# What Was Your Spark Plug Gap?



## XtremeRevolution (Jan 19, 2012)

If you changed your spark plug gap per this thread or this thread, please report what the original values were here. If you have yet to change them, please remember to report the original values. 

My case with GM has been escalated to a district case manager at GM to hopefully get some exposure on this issue. My primary goal is to allow people to go to their dealerships and have their spark plug gaps checked and corrected (as there has been a 100% error rate so far), and the more people and numbers I can present them with, the better. 

If your username is on the below list, I already have your numbers down. If not, please post them. I need specific values, such as ".022, .023, .025, .025." I will also need the model year of your Cruze. 

We have 37 cars recorded so far. I'd like to get at least 50. My current spreadsheet is also attached. 


InsaneSpeed Stevesciphigarrettb1Rosstudewilde74krlw1224crazylegsozman2005audiobahnmancalintzcharlie_tcecaa850Chevyderek72Ian_12whatsstuckk5XtremeRevolutioncoinneachtecollins1BeachernautRed Dragontwin1987churdlerVetterinUR2N0ZHiggs Bosonsilverram323OnlyTaurusjblackburnH3LLON3ARTHSlvrECObulletCampuscop2003haoleboyweimerrjUpstateNYBillEcoCruzerdanimal


----------



## spacedout (Dec 7, 2010)

looking at your spreadsheet, seems we should also be recording model years also. My 2012 was .019,.024,.025,.024


----------



## XtremeRevolution (Jan 19, 2012)

spacedout said:


> looking at your spreadsheet, seems we should also be recording model years also. My 2012 was .019,.024,.025,.024


Good suggestion. 

If those who have already reported their numbers would provide the year of their vehicle, I can certainly have that added to the spreadsheet. I will add those values for all newly reported gaps.


----------



## cecaa850 (Apr 9, 2012)

2012 mt 1.4t


----------



## Vetterin (Mar 27, 2011)

2011 Eco MT here. :goodjob:


----------



## obermd (Mar 3, 2012)

XtremeRevolution said:


> Good suggestion.
> 
> If those who have already reported their numbers would provide the year of their vehicle, I can certainly have that added to the spreadsheet. I will add those values for all newly reported gaps.


It would be nice to know if the engines are 1.8 or 1.4T as well. This may give us an idea about the severity of the problem for each engine.


----------



## XtremeRevolution (Jan 19, 2012)

obermd said:


> It would be nice to know if the engines are 1.8 or 1.4T as well. This may give us an idea about the severity of the problem for each engine.


I have been making a mental note of this and have not yet noticed any trends.

Sent from my Bulletproof_Doubleshot using AutoGuide.Com Free App


----------



## tecollins1 (Nov 6, 2011)

11' Eco m6


Sent from iPhone 4


----------



## UpstateNYBill (Jan 14, 2012)

2012 1lt


----------



## blk88verde (Apr 30, 2011)

I PM'd my info - I was surprised that my plugs were either .025 or .026 still under spec but pretty consistent. This is a May 2011 built ECO - Austrian built engine and transmission per the window sticker. By the way the total cost to check and regap plugs was $16 in tools and supplies. Gapping tool was $2, mini feeler guage $3, magnetic 5/8 plug socket $6 and anti sieze $5 from auto zone.


----------



## TechCruzer (Mar 15, 2012)

2012 ECO A/T Mfg. 11/11

I don't know the plug order, but left to right... 0.020, 0.025, 0.025, 0.020 are all now gapped to 0.035.


----------



## obermd (Mar 3, 2012)

2012 ECO MT, final assembly Oct 2011

0.023, 0.025, 0.025, 0.023

All now at 0.035 - 0.036


----------



## MafiaLTZ11 (May 29, 2011)

AS you know from the other thread; 3 out of four at .025 and one at .020


----------



## XtremeRevolution (Jan 19, 2012)

Spreadsheet updated. 

I've decided I'm going to go through it later and get the years. Easier than having every person post in this thread.

41 cars have currently been reported in this spreadsheet.


----------



## albow77 (Feb 18, 2012)

Mine were .024 .024 .025 .025 

2012 ECO 6m made in Aug 2011 -- if it helps the color is white!!!!


----------



## obermd (Mar 3, 2012)

For those of you who work better visually, I graphed Xtreme's sheet after adding albow77. There is a very definite peak at 0.025 with the plug gap margin of error being -0.002 +0.001.


----------



## sedanman (Dec 10, 2010)

Well you've convinced me to open her up and check.

Question: Where do you buy these spark plugs from? No online store carries them. Even the NGK website does not list 2011 Chevy Cruze as one of it's options.

I only ask in case I break the tip or something.


----------



## XtremeRevolution (Jan 19, 2012)

sedanman said:


> Well you've convinced me to open her up and check.
> 
> Question: Where do you buy these spark plugs from? No online store carries them. Even the NGK website does not list 2011 Chevy Cruze as one of it's options.
> 
> I only ask in case I break the tip or something.


Any auto store should have them. I can't imagine why they wouldn't. Absolute worst case, a dealer will have it. You can also use a different brand Iridium plug.


----------



## XtremeRevolution (Jan 19, 2012)

obermd said:


> For those of you who work better visually, I graphed Xtreme's sheet after adding albow77. There is a very definite peak at 0.025 with the plug gap margin of error being -0.002 +0.001.
> 
> View attachment 5841


That visual graph sure makes it look like NGK thought they were supposed to be .025, and there were serious quality control problems on top of that.


----------



## obermd (Mar 3, 2012)

XtremeRevolution said:


> That visual graph sure makes it look like NGK thought they were supposed to be .025, and there were serious quality control problems on top of that.


Agreed. There are now enough plugs (> 100) in the chart to start doing statistical analysis, but I think just seeing it graphically is sufficient. It also appears NGK was given the same spec for both the 1.4T and 1.8 engines, which makes me wonder if they shouldn't both be 0.035 +- 0.002, despite what both the owners manual and the GM service manuals say.


----------



## JeffBazell (Jan 24, 2012)

Checked today, 5/28/12:
2012 Cruze Eco 1.4, AT, 5800 miles: .028, .026, .028, .028. Only adjusted the .026 to .028. Now all in line with specs per the manual.


----------



## obermd (Mar 3, 2012)

JeffBazell said:


> Checked today, 5/28/12:
> 2012 Cruze Eco 1.4, AT, 5800 miles: .028, .026, .028, .028. Only adjusted the .026 to .028. Now all in line with specs per the manual.


I would go with the 0.035" what's in the GM maintainence manual. It's more current than the owners manual.


----------



## Kruise (Sep 28, 2011)

Checked the plugs after changing oil.

.025
.026
.025
.024

Now adjusted to .034. I haven't driven around yet.
Thanks for bringing this to our attention.


----------



## XtremeRevolution (Jan 19, 2012)

obermd said:


> I would go with the 0.035" what's in the GM maintainence manual. It's more current than the owners manual.


I'm not sure why some people still insist on using the owner's manual or what logic there is in assuming it is a more reliable authority than GM Global Connect, the GM service manual available to all dealerships, and AllData. The owner's manual was probably never updated since the production of the Cruze started. I'm fairly certain the same cannot be said of the service manuals.


----------



## Arcticat (Feb 16, 2012)

I have a 2012 ECO, the gaps where as follow's 26,27,27,26. I did change them to 33 on all four. Have not had a chance to drive it yet


----------



## XtremeRevolution (Jan 19, 2012)

Thank you to everyone who has provided their numbers. I've recorded everyone's results in my spreadsheet, which now has 49 vehicles and 196 plugs recorded. 

If looking at this spreadsheet, please note the orange highlighted values. These represent owners who provided an approximation, such as "all 4 were around .025." I believe that, for statistical reasons such as the graph provided on page two, it is important to include those.

The updated spreadsheet is attached.


----------



## 20126spdRS (Dec 27, 2011)

did my gaps last night and i found from right to left .019 .023 .021 .023
2012 M/T 1LT


----------



## XtremeRevolution (Jan 19, 2012)

20126spdRS said:


> did my gaps last night and i found from right to left .019 .023 .021 .023
> 2012 M/T 1LT


Wow. Those are all much lower than the average, and the 2nd person who has reported a .019 gap. How's it run now?


----------



## spacedout (Dec 7, 2010)

XtremeRevolution said:


> Wow. Those are all much lower than the average, and the 2nd person who has reported a .019 gap. How's it run now?



I had one at .019(which you recorded before I assume since I posted in this thread), My automatic had a surging missing type feeling between 1,200-2,000rpm when under load. That is completely gone, the engine feels like it makes more power. also seems to not struggle(revs quicker) above 4,000rpm.


EDIT: looking at the spreadsheet looks like my numbers were not recorded(the numbers are posted on the first page of the thread) _My 2012 1LT auto was .019,.024,.025,.024_


----------



## The Wolf Wagon (Mar 5, 2012)

Mine were .030 and regapped to .035. 2012 Eco A/T.


----------



## obermd (Mar 3, 2012)

For the two of you who reported the really small gaps, what are the last 6 digits of your VINs (if you don't mind)? I wonder if a shipment of spark plugs got banged up or dropped on the way to your cars.


----------



## fraser420 (Jun 26, 2011)

Just regapped to. 035. Left the to right they were. 024, .025, .024, .021. I'm in a 2011 eco manual. Definitely notice an increase in low end power aswell as a smoother acceleration overall, but I also put in a KN filter and bypassed the ressonater at the same time, so I can't say how much is due to the plugs


----------



## TechCruzer (Mar 15, 2012)

fraser420 said:


> Just regapped to. 035. Left the to right they were. 024, .025, .024, .021. I'm in a 2011 eco manual. Definitely notice an increase in low end power aswell as a smoother acceleration overall, but I also put in a KN filter and bypassed the ressonater at the same time, so I can't say how much is due to the plugs


I know I did, but you're probably seeing much of the performance improvement is due to the increase in the plug gaps... the filter & resonator delete is going to hopefully improve you MPG on top of what you might see over the plug gap increase. :th_dblthumb2: I did my resonator delete about 3 weeks ago (no K&N drop in yet) & saw a 1.5MPG increase. :yahoo: I'll see what my adjusting the plugs does after this weeks tank of gas.


----------



## aewid (Apr 16, 2011)

Mine is a 2011 LT2 bought in March 2011. With 20,500 miles on the car, the gaps from left to right facing the engine were: 0.026. 0.025, 0.023, 0.025.


----------



## aewid (Apr 16, 2011)

BTW, mentioned this thread to the dealer service advisor and what people were experiencing, 0.022 and lower in some cases, he said that that was way too tight and another guy shook his head in agreement. I told them about the .035 and they were thinking off the top of their heads much higher, but they might have been thinking something else, they weren't the techs.


----------



## crazytglo (May 30, 2012)

Just did mine today. All four were at .025. I re-gaped to .031. Should I go to .035?

2012 cruze ls


----------



## obermd (Mar 3, 2012)

crazytglo said:


> Just did mine today. All four were at .025. I re-gaped to .031. Should I go to .035?
> 
> 2012 cruze ls


The US spec is currently 0.028" - I saw this myself in the on-line service manual at my dealership. According to AC Delco Australia the overseas spec, converted to inches is 0.0315.


----------



## thekevin (Feb 21, 2012)

21 21 23 24 changed them all to 36 and I am amazed at how smooth the car accelerates now.

12 mt 1.4t


Sent from my Autoguide iPad app


----------



## XtremeRevolution (Jan 19, 2012)

Just updated the spreadsheet with the newest information. 57 cars have now been reported.


----------



## jdubb11 (Mar 14, 2012)

i copied and pasted 3 pages of quotes from the other gap thread and brought my car to the dealer. i told them i had some "boggie feel, and lack of throttle responce"(which was true) and wanted the gap checked. they said they would have to duplicate. i said to do what ever ya want, here is 3 pages of people with the same problem from a fourom online. service guy said they dont worry about internet stuff. i said good cuz here is the case # gm has on this issue. he said ohhhhh, well that deals with a specific person for that case. i said ok well here is her name and number. he said, ohhhh well we will take a look at it. they said the plugs were between .027 and .029 and they regapped them to .037. so good news is a got the dealer to do it. bad news is i didnt see for myself what they were and what they are now. i will just leave it if i feel the issues are better. if they presist i will check them again myself. it did feel a bit better but i only drove ten miles home so i will update later in the week


----------



## DMac1988 (Oct 3, 2011)

I had mine at(from left spark to right side while working on the engine) 
Left: .19 .20 .23 .19 then i changes them to .35

I have the 2011 ls 1.8l


----------



## llabahn (Feb 9, 2012)

I just re-gapped the plugs in my 2012 1LT 1.4 AT. All four were .025. Now they're .035. It ran pretty good before and seems about the same now.


----------



## Eddie & the Cruzer (Apr 10, 2011)

I have a 2011 1.4T ECO, 6-Spd Manual with Trifecta tune. Mine were .026, .026, .026 and .025.
They're now all at .029 and I don't feel much of a difference.
I'll monitor the gas mileage to see if I have any changes.
Great post!


----------



## unitednations161 (Mar 13, 2011)

2011 cruze eco mt, from right to left, my gaps were ..019 .019 .016 .025, regapped to .035. Alot better now, no hesistation now!


----------



## jblackburn (Apr 14, 2012)

Holy crap, .016?!?! Your car had to be bogging like crazy. 


Sent from my Autoguide iPhone app


----------



## obermd (Mar 3, 2012)

0.016 would explain why you were having such a hard time shifting smoothly.


----------



## unitednations161 (Mar 13, 2011)

jblackburn said:


> Holy crap, .016?!?! Your car had to be bogging like crazy.
> 
> 
> Sent from my Autoguide iPhone app


It was! Im only guessing at the .016 too it was smaller then the .019 gapper i had and a hair bigger then a .014 feeler gauge i have.


----------



## bruteforce (Mar 23, 2012)

Checked mine tonight. 1.4 ECO MT manufacture date of 5/12. Every plug was set at .025. At least they were all the same. Set the gap to .035 as suggested, and definitely noticed a difference as others have. I didn't get a great long distance test drive however, I did notice a difference. I even took it over to a friends house, who drove my car prior to me changing the gap and resonator removal, and had him drive it. His words, "What did you do to this thing"!? I told him, "the only thing I've done is remove the resonator, and gap the plugs". He couldn't believe the difference. It's funny, he has a new Malibu and is now searching forums to see if there is anything he can do to his to help with performance. Tomorrow, I will report back after I drive it to work (120 miles rnd trip) and see how it did. Thank you XtremeRevolution for posting this great find. Keep up the good work!

Thanks,
bruteforce
http://www.cruzetalk.com/forum/4009-xtremerevolution.html


----------



## XtremeRevolution (Jan 19, 2012)

Uploaded a new spreadsheet with the latest numbers. I changed the formatting a bit to make it easier to read, and added a smooth chart.


----------



## obermd (Mar 3, 2012)

Thanks. I think the chart just about says it all.


----------



## bruteforce (Mar 23, 2012)

XtremeRevolution said:


> Uploaded a new spreadsheet with the latest numbers. I changed the formatting a bit to make it easier to read, and added a smooth chart.


Could you add a vehicle manufacture date to this as well (assuming it has been provided)? Since all my plugs were the same, I'm curious if the issue has been somewhat looked at recently. Not saying they're set "right" but, at least they were all the same.


----------



## XtremeRevolution (Jan 19, 2012)

bruteforce said:


> Could you add a vehicle manufacture date to this as well (assuming it has been provided)? Since all my plugs were the same, I'm curious if the issue has been somewhat looked at recently. Not saying they're set "right" but, at least they were all the same.


I've seen many with a 2011 and a 2012 that also had the same consistency. I haven't noticed any correlation there.

Sent from my Bulletproof_Doubleshot using AutoGuide.Com Free App


----------



## ECRUZ (Mar 6, 2011)

So plugs 1, 2 and 3 were gapped at .025 and plug 4 was at .023...here is my question, my plugs look crappy after 27,567miles. Here is a picture of a plug, they all look the same, just curious to know what everyone else thinks? After the regap noticed a huge difference. It really is like night and day.









Sent from my HTC Rezound


----------



## chevyboy695 (Jun 17, 2011)

Did mine earlier 3 at .25 and 1 at .23... def smoother acc 2011 lt2 auto


----------



## unitednations161 (Mar 13, 2011)

obermd said:


> 0.016 would explain why you were having such a hard time shifting smoothly.


Yep, its much better now, the car barely made it up hills without bogging! I thought it was my lack of manual knowledge, nope, today i took a corner at 65 downshifted to 4th and pulled through it with ease, before it woulda hesiated like a pig at a slaughter house.


----------



## obermd (Mar 3, 2012)

I can run 87 octane again - even in the heat of summer. Before I regapped I had to run 91. Yeah!!!


----------



## jblackburn (Apr 14, 2012)

obermd said:


> I can run 87 octane again - even in the heat of summer. Before I regapped I had to run 91. Yeah!!!


My car is much improved from what it used to be. But I believe it still heat soaks in 90+ temperatures with AC running full blast in traffic, and on 87 it was bogging a bit trying to take off. Once I got going and got some airflow through the front of the car (it had been sitting in shopping centers and the like with a hot engine), taking off from the next stop wasn't bad at all. 

This never seems as pronounced on higher octanes - HOWEVER, the cars overall response on 87 octane is much better than when I first got the car. I'm thinking of doing the intake resonator delete this weekend to see if it will help cool down IAT temperatures a bit more at idle. 


Sent from my Autoguide iPhone app


----------



## bruteforce (Mar 23, 2012)

jblackburn said:


> I'm thinking of doing the intake resonator delete this weekend to see if it will help cool down IAT temperatures a bit more at idle.
> 
> 
> Sent from my Autoguide iPhone app


Do it! You won't regret it. It took me about 3 minutes..hood up to hood down. You will definitely notice the difference.


----------



## brian v (Dec 25, 2011)

how are you gapping iridium plugs took me 1 hour withpro feeler guage.
I also took great care to not destroy iridium tip . these are the hardest alloy spark plugs I have ever checked.
0.028 is the dwell I have .


----------



## XtremeRevolution (Jan 19, 2012)

brian v said:


> how are you gapping iridium plugs took me 1 hour withpro feeler guage.
> I also took great care to not destroy iridium tip . these are the hardest alloy spark plugs I have ever checked.
> 0.028 is the dwell I have .


I used the following tool set, which includes a tool (the one pointing downward) with which you can easily adjust the electrode without touching the tip. $7 at your local auto store. 










What was .028? Your original gap, or the gap you adjusted to?


----------



## Mattburgess (May 29, 2012)

2012 Eco automatic, .025 .026 .025 .026 all are set now to .028


----------



## NB983 (Jun 8, 2012)

G'day guys, 

A great read through this thread as well as the few others regarding the spark plugs gapping issues. I was referred to this site by a friend as no particular website for the Holden Cruze exists in Australia, though a facebook page does. This forum gets technical, and I like that.

I purchased my Holden Cruze SRiV (1.4 Turbo) in August last year. At the first 3000km service check, I advised the dealer of a rattle/knock coming from the engine. I was told it was the turbo. The very first service was at 15000km in March this year, and again I raised the issue about the knocking.

Compiling a few notes with a description of this issue, I put together that the engine was producing this noise in 3rd gear around the 2000-24000PRM range. At the conclusion of this service by the dealer, I was advised to alter the fuel type (from 95 premium octane to 98 premium) and see how that goes.

Various tanks of fuel later, nothing had changed. By this stage I raised a complaint with GM Australia for a full investigation as I believed a brand new Holden Cruze right from the first 1 kilometre had this knocking/rattle/pinging noise during acceleration and no dealer wanted to know about it.

After several weeks, as organised by Holden Head Office, I took my Cruze into a new service dealer and the plan was to keep the car for diagnosis for 2 days.

I received a text message 3 hours after I dropped it off to say it was ready. As I was away I didn't pick it up until last night. Sitting down with the dealer and going over the notes, the Manager's jaw literally fall to the desk... I said you seemed concerned and he replied with, 'The spark plug gaps were ALL OVER the place!'

I said, 'Excuse me?' Haha

They have been all adjusted, and unfortunately I do not have the figures as requested in the initial post of this thread, though I will try to find out.

I have noticed much better performance from the low end RPM range and a more spirited & lively drive. But, the engine knocking/pinging still exists.... I'd appreciate any comments or direction to a similar thread about this, if any. As Holden Australia Head Office has informed me, there have been no cases about the engine knocking...

Though when I speak to them on Tuesday, as they promised to call me back to follow this all up, I will be right on the spark plug debacle!


----------



## obermd (Mar 3, 2012)

Kermie,

It sounds like you ran into the same problem that occurs in the US a lot - crappy dealerships. The service manager at the second dealership seems to know what he's doing.


----------



## ECRUZ (Mar 6, 2011)

Kermie,

Well I hope you do get the numbers, and let us know what you hear or find out. As far as the pinging noise youre hearing, I think your problem is not rod knock, but cylinder slap. I have the same sound in my 1.8LS, but when I ask the dealer, they pretty much say its just me learning how to drive this new manual (Ive been driving this fat for over 27,000 miles) But anyways that should be your problem, that is what my buddy's shop told me. And the only real way to fix it would to be a complete rebuild. Sorry to stray off topic just wanted to throw out some information for Kermie.

Sent from my HTC Rezound


----------



## UpstateNYBill (Jan 14, 2012)

Kermie the SRiV said:


> They have been all adjusted, and unfortunately I do not have the figures as requested in the initial post of this thread, though I will try to find out.
> 
> I have noticed much better performance from the low end RPM range and a more spirited & lively drive. But, the engine knocking/pinging still exists.... I'd appreciate any comments or direction to a similar thread about this, if any. As Holden Australia Head Office has informed me, there have been no cases about the engine knocking...
> 
> Though when I speak to them on Tuesday, as they promised to call me back to follow this all up, I will be right on the spark plug debacle!


Adjusted to what?! 0.028, or 0.035? Ask them that too! If they set it to 0.028, further adjustment to 0.035 might be a next step.


----------



## bartonmd (Jun 30, 2011)

Mine were all right around .025 ('11 ECO manual). I adjusted them to .035, and even though I'm currently running 93 octane, idle is completely smooth (like "can't feel it running" smooth), and low end (like taking off from a stop) is also much smoother.

Mike


----------



## Rockerxink820 (Aug 8, 2011)

Well i checked mine today and there gap was all .019 so i regapped them all to .035 and i have a 2011eco mt


----------



## spacedout (Dec 7, 2010)

Rockerxink820 said:


> Well i checked mine today and there gap was all .019 so i regapped them all to .035 and i have a 2011eco mt


Would love to hear if you noticed any difference in your car, I bet it revs up quicker & has a much smoother idle & throttle response. GM should be checking all cars with as many of these that are out of spec.


----------



## XtremeRevolution (Jan 19, 2012)

Rockerxink820 said:


> Well i checked mine today and there gap was all .019 so i regapped them all to .035 and i have a 2011eco mt


Wait, so you're saying all 4 of them were at .019??? I can't begin to imagine how horribly your car ran before you adjusted them.


----------



## gman19 (Apr 5, 2011)

I checked and re-gapped my plugs today, all were out.
From the driver's side they were: *0.024", 0.024", 0.024" & 0.025".
*All are now re-gapped to 0.035". I will not be driving her until Monday so I'll know then how she drives.

I am about 100 miles into my latest fill-up, so if I go farther than about 530 miles, it may be an indicator of a little MPG increase.
I will run a couple tanks thru and re-visit 'CUDA's poll and respond with my findings.


----------



## wallbngr (Feb 2, 2012)

Rockerxink820 said:


> Well i checked mine today and there gap was all .019 so i regapped them all to .035 and i have a 2011eco mt


What color were they , I would bet they were all Dark and I'm wondering if you even had much Lowend power.. 
The color they should be is a tan color ,not black . Black is too cool ...


----------



## wallbngr (Feb 2, 2012)

What is happening here?? There is so much variation in the gaps here ... But it seems like theat Most of them are WAY too small


----------



## wallbngr (Feb 2, 2012)

ECRUZ said:


> So plugs 1, 2 and 3 were gapped at .025 and plug 4 was at .023...here is my question, my plugs look crappy after 27,567miles. Here is a picture of a plug, they all look the same, just curious to know what everyone else thinks? After the regap noticed a huge difference. It really is like night and day.
> 
> View attachment 6002
> 
> ...


Looked like mine did when I took them out to regap.. Looks too cool


----------



## ECRUZ (Mar 6, 2011)

Like maybe running to cool or just saying it is too cool? :iagree: with wallbngr's previous post, there is a lot of variation between the gaps. but how can it be when they are all from the same company and all machine built? :uhh:


Oh yea and I also forgot to say that all but one plug was barely hand tight and none of the crush washers (except for one) was crushed...seems a little shady to me :$#angry: :wtf:


----------



## XtremeRevolution (Jan 19, 2012)

wallbngr said:


> What is happening here?? There is so much variation in the gaps here ... But it seems like theat Most of them are WAY too small


Why do you think I made such a big deal out of this? Between the 3 threads I created, there are 25,000 views. 



ECRUZ said:


> Like maybe running to cool or just saying it is too cool? :iagree: with wallbngr's previous post, there is a lot of variation between the gaps. but how can it be when they are all from the same company and all machine built? :uhh:
> 
> 
> Oh yea and I also forgot to say that all but one plug was barely hand tight and none of the crush washers (except for one) was crushed...seems a little shady to me :$#angry: :wtf:


Shady would be generous, lol. Not only is the consistency terrible, but based on the averages, we can come to a conclusion as to what *someone* thought they should have been, which points blatantly to .025". However, the only place that .025 is within spec is the document from the EPA for emissions testing where they noted the Cruze 1.4T motor's spark plug gap spec is .0236-.0276. No other document from GM or elsewhere indicates that this is anywhere close to correct.

With gman's spec, we have 70 cars reported. I'll post the spreadsheet again on Monday. That said, I highly encourage everyone who will do this to continue to report their spark plug gaps. Perhaps we can start seeing a trend if GM were to finally take note of this error and make some corrections. It wouldn't surprise me if all of a sudden, people started reporting higher gaps when checking their plugs.


----------



## BladeOfAnduril (Apr 27, 2012)

I'm going to try to check mine tomorrow. My car was built 3 weeks ago, so probably one of the most recently produced cars on here. I'll post back with the results. 

Sent from my Galaxy Nexus using AutoGuide.Com Free App


----------



## Nickerbacher (Jan 17, 2012)

My 2012 Eco 1.4 had all 4 plugs around .024-.025. I regapped to .035 and will post back on mileage as well as driveability as soon as I drive it a bit.


----------



## ECRUZ (Mar 6, 2011)

Well whatever the reason is, I hope Faust someone at GM realizes that there is room for improvement in both R&D and in the factories...I am loyal to GM and will always be, but this upsets me and I'm sure everyone else feels the, especially for such an easy fix such as this.

Sent from my HTC Rezound


----------



## andrewm2002 (Jul 27, 2011)

2011 ECO MT All were .024 to .025... seemed in between. I set them all to .028 (I'm tuned so I'm gonna follow the tuned crowd and stay under .03)


----------



## Record_player (Nov 16, 2011)

2011 LTZ all were .025 - .024. set all them to .030.(tuned)


----------



## BladeOfAnduril (Apr 27, 2012)

I just finished doing my spark plugs. All 4 were gapped at .025. I have regapped them all to .035. My car was built 3 weeks ago.


----------



## obermd (Mar 3, 2012)

BladeOfAnduril said:


> I just finished doing my spark plugs. All 4 were gapped at .025. I have regapped them all to .035. My car was built 3 weeks ago.


So either GM has done nothing or there are still misgapped plugs in the supply line. My bets are on both.


----------



## Kinmartin0789 (Feb 18, 2011)

this point i doubt gm knows enough about it yet. Your best bet is to just gap them your slef and make sure your dealership knows about it. I printed this forum out and brought it to my dealership and they offered to regap them for free. I had already done it so it doesnt matter. The dealership let me know the process on how these things work and how slow the message would get to GM. R&D made sure the cars run, which they do. NGK has alot of the balme in my mind, in fact i messaged them and havent heard anything back yet.


----------



## obermd (Mar 3, 2012)

Kinmartin0789 said:


> this point i doubt gm knows enough about it yet. Your best bet is to just gap them your slef and make sure your dealership knows about it. I printed this forum out and brought it to my dealership and they offered to regap them for free. I had already done it so it doesnt matter. The dealership let me know the process on how these things work and how slow the message would get to GM. R&D made sure the cars run, which they do. NGK has alot of the balme in my mind, in fact i messaged them and havent heard anything back yet.


NGK would only have blame for the inconsistency in gaps. It really appears GM gave the wrong spec to NGK. As for GM, they know about it. That's one of the reasons GM set up their Social Media unit - to let GM corporate know when owners of GM products find problems with their cars. Note to Stacy - this isn't a ding on your being here, just an observation on the mission of GM's Social Media unit. Whether or not GM will do anything unless the media gets involved is a different question entirely.


----------



## obermd (Mar 3, 2012)

:iagree:


----------



## ECRUZ (Mar 6, 2011)

Well I just hope that something is going to happen soon...it's not that it is hard to do, but it's the fact that it should have been done from the factory...has anyone talked to our GM Rep about this yet?

Sent from my HTC Rezound


----------



## XtremeRevolution (Jan 19, 2012)

ECRUZ said:


> Well I just hope that something is going to happen soon...it's not that it is hard to do, but it's the fact that it should have been done from the factory...has anyone talked to our GM Rep about this yet?
> 
> Sent from my HTC Rezound


In my case, 4 GM reps, one district case manager, and Stacy on this board, who came back saying that some "subject expert" told her in an internal email that the owner's manual is CORRECT and the service manual is WRONG. I capitalized those words because she did as well in her quote of that email. Supposedly GM Powertrain is working on "fixing" the service manual. Really? This is after the district case manager I worked with insisted that I should consult with my dealership for clarification if in doubt. 

I question if that "subject expert" is from a legal or risk management department. Per the other large thread regarding this topic, I sent an email to a contact over in GM Powertrain on Friday night. I'm waiting for a reply on that since customer service is hesitant to offer any useful information. 



Here's my message to anyone from GM that may be reading this thread. You have a finite amount of time left before I contact my local media regarding this issue as I'm running out of options. That time will expire when I have recorded 100 people in my spreadsheet. We are now at ~70 within a month's time. I figure 100 owners and 400 spark plugs with a very broad demographic should be plenty (as if the data isn't conclusive enough already), and you (GM) have had long enough to respond responsibly.


----------



## ECRUZ (Mar 6, 2011)

Thanks for the update, and for your extreme diligence in helping us fellow Cruzers get this issue rectified.

Sent from my HTC Rezound


----------



## XtremeRevolution (Jan 19, 2012)

70AARCUDA said:


> ...with no disrespect toward Stacy whatsoever, but maybe GM should be consulting a _"...*SPARK PLUG *(GM-Powertrain) expert.." _rather than a _"...*SUBJECT* expert..." _(which IMHO is _merely_ PR-speak for "dummy")?


I asked her for the name or at least title of this "subject expert" in my first response and she didn't respond to that question. I asked her again in my second response. I wonder if she'll come back with anything. 

I'm simply not buying it. This feels like dirt swept under the rug.


----------



## ECRUZ (Mar 6, 2011)

It would not be the first time.

Sent from my HTC Rezound


----------



## Starks8 (Jul 20, 2011)

I SAY WE TAKE THIS ISSUE TO THE STREETS, LOL!! And by the streets I mean both the local and national news & newspapers, Youtube, as well as the Chevy Cruze Facebook page!! We know that people worship Facebook and Youtube, so XtrmeR, you and the rest of us should start there. GM/Chevy better get their stuff together with this issue and the car as a whole ASAP! Not only are under-gapped spark plugs an issue but, it looks like the reason why some Cruze owners feel their A/C's aren't cold enough *may* be because of a lack of the right amount of refrigerant.


----------



## ECRUZ (Mar 6, 2011)

Not to sound like an idiot, but don't GM pin the problem on us since we are doing our own maintenance on our cars? But I do agree, we should go local/live?

Sent from my HTC Rezound


----------



## XtremeRevolution (Jan 19, 2012)

I'll give it till Wednesday to let that guy from GM Powertrain respond before I give up dealing with GM directly.

Sent from my Bulletproof_Doubleshot using AutoGuide.Com Free App


----------



## NeonRyder (Jan 3, 2012)

I gapped mine this weekend to .036", the car "seems" to be smoother and to have more power, but that may be due to the placebo effect...
Gaps when pulled were .025, .026, .025 and .025.


----------



## rbtec (Feb 3, 2012)

I am going to try and get the dealer to gap mine. What should the gap be? I am thinking of telling them to gap to .034, the low end of the spec in the service manual.


Sent from my Autoguide iPhone app


----------



## Pruittx2 (Mar 24, 2012)

My 2011 RS were around 26-27,,, I changed them to 35.

IF I were to buy a new set of plugs, to have the best possible plug in my car,,,, WHAT PLUG WOULD IT BE?


----------



## bartonmd (Jun 30, 2011)

XtremeRevolution said:


> I asked her for the name or at least title of this "subject expert" in my first response and she didn't respond to that question. I asked her again in my second response. I wonder if she'll come back with anything.
> 
> I'm simply not buying it. This feels like dirt swept under the rug.


I agree. Crap like this is why I swore I was buying Ford or Honda stuff from now on, but I made the exception for the ECO (the GM employee discount didn't hurt). It's not the issue. There are going to be issues. It's the handling of the issues.

Mike


----------



## rbtec (Feb 3, 2012)

Since the Chevy Sonic has the same engine as the Cruze, I checked the Chevy Sonic owners manual and it says the gap should be .028 as well. I wonder what All-Data or the Sonic service manual says the gap should be.


----------



## XtremeRevolution (Jan 19, 2012)

I'm getting the run-around from Tom Read at GM. He's avoiding all of my questions and blaming all of the variance we've measured on user error. I will be posting his reply as soon as I can determine where to do so.


----------



## jblackburn (Apr 14, 2012)

So he's basically saying that 100+ people are idiots and can't read 400+ spark plugs on a gauge?

Yeah, I'm *sure* it's user error...


----------



## XtremeRevolution (Jan 19, 2012)

jblackburn said:


> So he's basically saying that 100+ people are idiots and can't read 400+ spark plugs on a gauge?
> 
> Yeah, I'm *sure* it's user error...


Precisely. I became a bit irritated to say the least. Sounds like I'm talking to a lawyer, not a GM Powertrain representative.


----------



## obermd (Mar 3, 2012)

GM has probably closed ranks and notified their powertrain folks to not say anything by this time. I can see the variance being somewhat subjective, but the peak at 0.025 isn't. I know my two plugs that I reported at 0.023 were an estimate based on the wire gapper I have just barely not slipping through at 0.025. The 0.025 loop just slipped through the other two tools, touching the wire but not blocking it.


----------



## jblackburn (Apr 14, 2012)

As someone pointed out above, it's not so much that they WILL fix something in the end - it's the amount of crap you have to put up with to get it to happen that drives them away. GM seems to be treating customers with issues, big or small as this is, like idiots on the issues they're having. Saying it's just their fault and that's how the car was designed.

Sounds like GM's policy is to blame the drivers for every issue rather than their quality control. Some people may remember the batch of bad clutches in the Cruze, as well as the spark plug gap, AC condensers being hit by rocks, front struts clunking, AC systems not being properly charged (this may be the next one - mine was definitely low), etc.

My parents have owned 2 Chrysler vehicles that have been *mostly* reliable, but after having to jump through hurdles and 3 dealerships to get a slipping transmission replaced on the Jeep, they will never buy another. And they never fixed the sliding door that hung up on the Town & Country properly.

I will never own another Volvo for the absolutely ridiculous cost of fixing things, and never being able to find a good mechanic or dealer that doesn't bend you over a barrel. It turns out that with the help of forums of knowledgeable people that I'm the best mechanic for one of those I've happened to find.

Ford & Honda dealerships for us have always fixed the issue - if there was one - right away and without hassle.


----------



## bartonmd (Jun 30, 2011)

XtremeRevolution said:


> Precisely. I became a bit irritated to say the least. Sounds like I'm talking to a lawyer, not a GM Powertrain representative.


A quick Googling tells me that Tom Reid/Reed is the GM Powertrain spokesman. Doesn't mean he isn't a lawyer, or doesn't get what he says OK'd by the legal Dept.

Mike


----------



## XtremeRevolution (Jan 19, 2012)

I'd like to provide an update. Within minutes of replying to Tom Read regarding my concerns and venting a bit of frustration regarding his response and the lack of a cohesive answer, I received a phone call directly from him, since I provided him my phone number in my first email. He sounded genuinely concerned. +1 for Tom Read. 

I had a lengthy discussion with him, and it was a breath of fresh air to speak to someone that wasn't from customer service that not only had access to some real resources at GM but also appreciated what I was doing. The way he put it, despite having corrected this issue on my end, I was acting on behalf of everyone else on this forum, taking my time to gather as well as compile information to help *GM*, who already sold *me *the car, and he was quite appreciative of that fact. I'd personally like to extend that appreciation to everyone who returned to this forum and provided their own measured spark plug gaps. 

Moving forward, he promised that he'd send me an official statement regarding what the correct spark plug gap is, and who it came from. To cut to the chase, the correct gap is .028" which he has 100% certainty of. He was able to speak to a service engineer over in Powertrain who had specific knowledge of the 1.4L Turbo motor and confirm that this was the gap set by GM. I'll follow up to this email with his statement. _In my mind_, this concludes what _*GM says*_ the spark plug gap should be. The confirmation to this will be when the service manual is corrected. However, it does _not _indicate or _imply _what the optimal spark plug gap is for each of us with regard to power delivery or fuel economy. I will personally keep my gaps at .035 as the results have been appreciable, and those with tuned motors will need to make their own decisions. 

Tom will be investigating why the dealership service manual differs from that of the owner's manual, and I have asked that he keep me updated. He will also be investigating the automatic transmission fluid capacity specification in the owner's manual. He made it very clear that I should call him directly if I have any further questions or need to speak about any other issues. 

I can finally say that I have found someone at GM who can handle this situation appropriately. I have a feeling I will be in contact with him quite often.


----------



## rbtec (Feb 3, 2012)

XtremeRevolution said:


> I'd like to provide an update. Within minutes of replying to Tom Read regarding my concerns and venting a bit of frustration regarding his response and the lack of a cohesive answer, I received a phone call directly from him, since I provided it in my first email. +1 for Tom Read.
> 
> I had a lengthy discussion with him, and it was a breath of fresh air to speak to someone that wasn't from customer service that not only had access to some real resources at GM but also appreciated what I was doing. The way he put it, despite having corrected this issue on my end, I was acting on behalf of everyone else on this forum, taking my time to gather as well as compile information to help *GM*, who already sold *me *the car, and he was quite appreciative of that fact. I'd personally like to extend that appreciation to everyone who returned to this forum and provided their own measured spark plug gaps.
> 
> ...


So, will dealerships gap to .028 if you request it or will they say they have to gap to the service manual in order to not void the warranty?


----------



## XtremeRevolution (Jan 19, 2012)

rbtec said:


> So, will dealerships gap to .028 if you request it or will they say they have to gap to the service manual in order to not void the warranty?


That, I honestly do not know. Since this will be done by the dealership as an act of good-will anyway given the absence of a TSB or one's ability to reproduce an issue on the spot, they may be willing to gap to whatever it is you request.


----------



## bartonmd (Jun 30, 2011)

XtremeRevolution said:


> I'd like to provide an update. Within minutes of replying to Tom Read regarding my concerns and venting a bit of frustration regarding his response and the lack of a cohesive answer, I received a phone call directly from him, since I provided him my phone number in my first email. He sounded genuinely concerned. +1 for Tom Read.
> 
> I had a lengthy discussion with him, and it was a breath of fresh air to speak to someone that wasn't from customer service that not only had access to some real resources at GM but also appreciated what I was doing. The way he put it, despite having corrected this issue on my end, I was acting on behalf of everyone else on this forum, taking my time to gather as well as compile information to help *GM*, who already sold *me *the car, and he was quite appreciative of that fact. I'd personally like to extend that appreciation to everyone who returned to this forum and provided their own measured spark plug gaps.
> 
> ...


It's really good to hear that Mr. Reid/Reed/Read (Have seen it all 3 spellings, depending on which rag it's in) stepped up to the plate with a real answer!

Unless I hear something negative about the larger .035" gap, I'm going to leave it. Unless there's something specific about this setup, it really just means higher ignition voltages, a bit shorter plug life, and a little more heat in the coil. Since I'm totally stock, my ignition voltages aren't as high as you guys running higher boost (The voltage required to jump the gap on the spark plug is directly related to cylinder pressure. More boost = more cylinder pressure = more voltage = more heat in the coil), and if it works for you, long term, it should work for me. 

My wife called my on the way back from an 8 hour trip to drop off a foster-dog at his new home, yesterday. She said "I wasn't listening when you told me what you were doing to the car, but whatever it was, it's awesome! Easier to take off on hills, holds speed better in 6th on hills, and the DIC shows I'm getting 42mpg!" (She drives hard, it was 90F with the A/C on high, 2 of the 8 hours of driving were through a city, and she would normally get ~38-39 on a trip like this, where I would normally get 43-44).

Mike


----------



## XtremeRevolution (Jan 19, 2012)

bartonmd said:


> It's really good to hear that Mr. Reid/Reed/Read (Have seen it all 3 spellings, depending on which rag it's in) stepped up to the plate with a real answer!
> 
> Unless I hear something negative about the larger .035" gap, I'm going to leave it. Unless there's something specific about this setup, it really just means higher ignition voltages, a bit shorter plug life, and a little more heat in the coil. Since I'm totally stock, my ignition voltages aren't as high as you guys running higher boost (The voltage required to jump the gap on the spark plug is directly related to cylinder pressure. More boost = more cylinder pressure = more voltage = more heat in the coil), and if it works for you, long term, it should work for me.
> 
> ...


Mike, 

It's for this reason that I think my own recommendation will remain to .035", simply because of the benefits realized by everyone who have gapped to that spec. That said, I will believe that .028" is the correct spec _per GM_ when I see it in the service manual, but I'm taking Mr. Read's word for it.


----------



## ECRUZ (Mar 6, 2011)

I like we finally found someone with an actual concern for its customers. And thank you again to Xtreme for all your hard work. Side question, would Mr. Read know anything about the manual transmissions notchy shifting? Just throwing it out there, not meaning to change thread topics...

Sent from my HTC Rezound


----------



## XtremeRevolution (Jan 19, 2012)

ECRUZ said:


> I like we finally found someone with an actual concern for its customers. And thank you again to Xtreme for all your hard work. Side question, would Mr. Read know anything about the manual transmissions notchy shifting? Just throwing it out there, not meaning to change thread topics...
> 
> Sent from my HTC Rezound


You're welcome. 

I can bring it up, but I may be able to answer your question. A few members noted that changing their manual transmission fluid offers incredible differences over the stock fluid. A thread was created with a how-to for this here:

http://www.cruzetalk.com/forum/57-how-forum/6627-how-change-manual-transmission-fluid.html

Re-filling it with a quality synthetic transmission fluid such as Amsoil Synchromesh should alleviate the problem and vastly improve shifting quality. 

I personally have two quarts of it sitting in my garage, waiting for some decent weather so I can drain the old and put in the new.


----------



## Sweber (Jun 11, 2012)

Just bought my Cruz yesterday but I plan on checking the Gaps this weekend. I told the manager about this forum thread while buying the car and he said if I check my gaps and they are incorrect they will adjust them, although if I go through all the trouble of checking them I don't see why I wouldn't just adjust them also.

He also thanked me for letting him know as his wife drives the cruze and he said he would be checking hers ASAP as well.


----------



## XtremeRevolution (Jan 19, 2012)

Here we are Gentlemen:



> Hi Mr. Pop,
> 
> Thank you for the phone conversation and again thanks for bringing this to our attention. I will assure you your concerns and findings will be forwarded on to my engineering and manufacturing contacts.
> 
> ...


This was in response to my previous email sending him the spreadsheet I've been compiling, which now has 75 total vehicles recorded. Should raise a few eyebrows over at GM when it starts getting around. 

In the above, he confirms an error in the GM service manual (spark plug gap) as well as an error in the owner's manual (Trans fluid capacity). 

Making progress!!!


----------



## Hoon (Mar 18, 2012)

Just checked mine (2012 1LT). 

.025-.026 across the board. 

Regapped to .028


----------



## obermd (Mar 3, 2012)

Hoon said:


> Just checked mine (2012 1LT).
> 
> .025-.026 across the board.
> 
> Regapped to .028


Hoon,

A lot of us have regapped to the 0.035 listed in the service manual. Please let us know how your car responds to regapping to 0.028".


----------



## Hoon (Mar 18, 2012)

obermd said:


> Hoon,
> 
> A lot of us have regapped to the 0.035 listed in the service manual. Please let us know how your car responds to regapping to 0.028".


.003" can be enough of a change to make a significant difference with spark blowout issues, but i don't think it will be enough to see a noticeable difference in fuel economy or power/throttle response. 

I will post up any changes, but i'm not expecting much.


----------



## XtremeRevolution (Jan 19, 2012)

Hoon said:


> .003" can be enough of a change to make a significant difference with spark blowout issues, but i don't think it will be enough to see a noticeable difference in fuel economy or power/throttle response.
> 
> I will post up any changes, but i'm not expecting much.


I don't believe anyone on .035 has been experiencing spark blowout with the stock motor. Those that did experience spark blowout were Trifecta tuned motors that were gapped down to .027-.029.


----------



## ECRUZ (Mar 6, 2011)

XtremeRevolution said:


> You're welcome.
> 
> I can bring it up, but I may be able to answer your question. A few members noted that changing their manual transmission fluid offers incredible differences over the stock fluid. A thread was created with a how-to for this here:
> 
> ...


XR again that you very much for the assistance. You are a great asset to the CT community.

Sent from my HTC Rezound


----------



## bh04 (Aug 5, 2011)

I've went through the last 3-4 pages on this thread. I'm trifecta tuned with K&N intake. When I check mine, what should they be gapped at? I'm kinda curious to see. I've only got 14k miles on my 2011 LT 6A


----------



## XtremeRevolution (Jan 19, 2012)

bh04 said:


> I've went through the last 3-4 pages on this thread. I'm trifecta tuned with K&N intake. When I check mine, what should they be gapped at? I'm kinda curious to see. I've only got 14k miles on my 2011 LT 6A


Anywhere from .027 to .029 if you have the Trifecta tune. I'd go .029, and if you feel a misfire or blowout, drop down a bit.


----------



## Hoon (Mar 18, 2012)

XtremeRevolution said:


> I don't believe anyone on .035 has been experiencing spark blowout with the stock motor. Those that did experience spark blowout were Trifecta tuned motors that were gapped down to .027-.029.


I'm not saying specifically with the Cruze, just generally speaking about plug gaps. 

I'll probably end up tuned sooner or later, and considering the factory spec is .028 i'm fine with that, not because i was expecting blowout with a larger gap on the stock tune.


----------



## Starks8 (Jul 20, 2011)

There are a lot of Chevy Cruze owners on the Chevy Cruze Facebook page, some of which most likely don't know about this forum, that need to know this and would be very appreciative of this information about the Cruzes' undergapped spark plugs. Extreme Revolution, would you like to do the honors of letting these Facebook Cruze owners know since you are the pioneer on this issue? Thanks for all your hard work and to everybody else who has busted their humps to get our questions and concerns addressed accordingly!


----------



## Starks8 (Jul 20, 2011)

XtremeRevolution said:


> Here we are Gentlemen:
> 
> 
> 
> ...


Hey ExtremeR- Are you completely satisfied with the answer he gave you about the transmission fluid? He still didn't specifically say how much transmission fluid should be put back in after a change? Is there any way we can get a real amount that should be going in after a trans fluid change? Thanks again!


----------



## XtremeRevolution (Jan 19, 2012)

Starks8 said:


> Hey ExtremeR- Are you completely satisfied with the answer he gave you about the transmission fluid? He still didn't specifically say how much transmission fluid should be put back in after a change? Is there any way we can get a real amount that should be going in after a trans fluid change? Thanks again!


Yeah, I trust that spec. It matches the service manual. The drain amount for the automatic trans when the drain plug is removed is 5.8 quarts.

Sent from my Bulletproof_Doubleshot using AutoGuide.Com Free App


----------



## XtremeRevolution (Jan 19, 2012)

Starks8 said:


> There are a lot of Chevy Cruze owners on the Chevy Cruze Facebook page, some of which most likely don't know about this forum, that need to know this and would be very appreciative of this information about the Cruzes' undergapped spark plugs. Extreme Revolution, would you like to do the honors of letting these Facebook Cruze owners know since you are the pioneer on this issue? Thanks for all your hard work and to everybody else who has busted their humps to get our questions and concerns addressed accordingly!


Do you know of any groups in particular that should be notified?


----------



## Starks8 (Jul 20, 2011)

XtremeRevolution said:


> Do you know of any groups in particular that should be notified?


Well, there isn't a specific group(s) per-say, but there is a Chevy Cruze Facebook page and just posting this and other important information like we have here on the page's wall, will be able to be seen by all, both the page's members and visitors. Here is the link to the page, https://www.facebook.com/chevycruze. There is also another good Chevy Cruze forum Chevrolet Cruze Forum although I think a majority of these members are not in the US but I think more US cruze owners are becoming members of that forum as well.


----------



## Big Tom (Mar 8, 2011)

Left to right... 0.025, 0.025, 0.023, 0.025. Installed new plugs gapped to 0.035.
2011 LTZ 1.4 Auto, 36,900 miles


----------



## Starks8 (Jul 20, 2011)

XtremeRevolution said:


> Yeah, I trust that spec. It matches the service manual. The drain amount for the automatic trans when the drain plug is removed is 5.8 quarts.
> 
> Sent from my Bulletproof_Doubleshot using AutoGuide.Com Free App


so 2.7 quarts of automatic trans fluid will still be in the system at each change? So each time, the appropriate amount of fluid to be put back in would be the same 5.8 quart amount that was initially drained, so that when done, the automatic trans fluid amount is back up to the 8.5 quart spec level?


----------



## XtremeRevolution (Jan 19, 2012)

Big Tom said:


> Left to right... 0.025, 0.025, 0.023, 0.025. Installed new plugs gapped to 0.035.
> 2011 LTZ 1.4 Auto, 36,900 miles


Wow, that's a lot of miles! How's the car running?


----------



## XtremeRevolution (Jan 19, 2012)

Starks8 said:


> so 2.7 quarts of automatic trans fluid will still be in the system at each change? So each time, the appropriate amount of fluid to be put back in would be the same 5.8 quart amount that was initially drained, so that when done, the automatic trans fluid amount is back up to the 8.5 quart spec level?


That would be correct.


----------



## Starks8 (Jul 20, 2011)

XtremeRevolution said:


> That would be correct.



okay great, thanks! Now what are the correct fluid amounts for these things when doing oil changes?


----------



## XtremeRevolution (Jan 19, 2012)

Starks8 said:


> okay great, thanks! Now what are the correct fluid amounts for these things when doing oil changes?


Check the dipstick, lol. I believe it's 4 quarts, maybe 4.5. Fill up to however much the dipstick shows is full.


----------



## Cruze572 (Dec 20, 2011)

2011 ECO, 14k, .023, .025, .024, .024. Plugs are now set to .035.


----------



## Big Tom (Mar 8, 2011)

XtremeRevolution said:


> Wow, that's a lot of miles! How's the car running?


Runs great, no problems. Air could be a little colder, mileage could be a little better but overall a great car.


----------



## NB983 (Jun 8, 2012)

UpstateNYBill said:


> Adjusted to what?! 0.028, or 0.035? Ask them that too! If they set it to 0.028, further adjustment to 0.035 might be a next step.


I will let you know shortly re plug gaps... The plan is to get the car in again very soon to replace the map lights fitting as well as follow up the engine rattle.


----------



## NB983 (Jun 8, 2012)

A case I have open with Holden Australia still remains at this stage regarding this spark plug gaping issue... Since the Series II Cruze is assembled in Australia and recently talking and shall continue with one of their Customer Service Reps, I put forward my concerns that the Cruze being sold here and also exported to the US and being sold is a little embarrasing for Holden/GM to turn a blind eye to something so simple like this. Holden have advised me that my such experience and comments will be directed appropriately and on this, I have made them aware of not only the Holden Cruze facebook page, but also CruzeTalk.com and this thread along with another which is 27 pages (maybe more by now). GM overall should start using these forums, not necessarily to comment or reply at this stage, but to at least read through what customers like us are saying. Holden Australia have warmly acknowledged these comments. I shall keep you posted.


----------



## GM_6T40_Trans_Engineer (Feb 26, 2011)

XtremeRevolution said:


> He will also be investigating the automatic transmission fluid capacity specification in the owner's manual.


What's your issue with the ATX fluid capacity?


----------



## UpstateNYBill (Jan 14, 2012)

XtremeRevolution said:


> Wow, that's a lot of miles! How's the car running?


Ehhh, I'm at 19,000 miles in 6 months so I'll have that in another 6 months. :th_coolio: or :angry:, depending on how I want to look at it. But CruzeEcoBlueTopaz will have him beat in no time, he's running more than even me. Look to him to find out all the problems once our Cruzes get up there in miles, and then maybe me. lol

I'm still finding my gas mileage going up, overall. Today, I filled up, hopped on the highway for a bit, then a short trip through the city, and then back on the highway for a while. The DIC was reading in the low 40's for mpg's, and still going up when I had to get off the highway and go up a mountain (almost 2000' of elevation change), which killed that. I got quite a bit of it back going down again but I still have to go up another 1300' or so at the end of the day to get home too. 

I attribute the overall improvement in gas mileage to the car breaking in, changing my spark plug gap to .035, and increasing my tire pressure to 44 psi, but how much to attribute to each is anyone's guess.


----------



## XtremeRevolution (Jan 19, 2012)

GM_6T40_Trans_Engineer said:


> What's your issue with the ATX fluid capacity?


It's listed as 4L or 4.2 quarts capacity in the owner's manual. It's correct for the MTX, but not the ATX. This was the reason so much doubt was cast on the accuracy of the spark plug gap spec.

Someone trying to save a few bucks on a trans fluid change might not measure how much they drained when pulling the drain plug (which drains 5.8 quarts) and put only 4.2 quarts back in. Kind of a problem.

Sent from my Bulletproof_Doubleshot using AutoGuide.Com Free App


----------



## XtremeRevolution (Jan 19, 2012)

Attached the most recent spreadsheet. 79 vehicles or 316 plugs reported so far. The trends continue with a sharp peak at .024"-.026", with disturbing amounts of variation below that. All it takes is one under-gapped plug to foul up the whole car.

I also sent another email over to Tom Read to check in on the progress of his investigation.


----------



## XtremeRevolution (Jan 19, 2012)

I'm liking this Tom Read guy. He seems to prefer to respond to me via phone instead of email, and promptly at that. 

He spoke to two service engineers who owned Chevy Cruzes, and they went out and checked the gap on their cars, then came back. One of them gave him exact specs, and said that they were at .025". Basically, GM now knows there's a big issue when their own engineers can confirm it with their own cars. He told me they have a lot of people working on this issue right now, investigating the assembly line as well as dealing with vendors to determine where the problem is. He mentioned a conference call he had in a few minutes regarding this very issue, so safe to say, my conversations with him have definitely created a great deal of exposure. 

Thanks again to everyone who took the time to measure and report their spark plug gaps back. The spreadsheet I was able to put together with that information really helped push for an investigation. Now that the issue is confirmed internally, this should get interesting. 

I also reminded him about the automatic transmission spec, and he said he'll ask about that as well in his next meeting.


----------



## jblackburn (Apr 14, 2012)

Good news! It's nice when you actually find someone in the chain of bureaucracy that can actually accomplish something, isn't it?

Reminds me of having to deal with Verizon at times...trying to get someone that actually knows what they're _*doing*_ on the other end of the phone.

I'd be interested to know what they determine the preset gap is supposed to be, but I definitely won't be changing my plugs back. It runs swimmingly well on .035", so much so that I have gotten used to shifting under 2000 RPM most of the time around town and can be in 5th or 6th gear at 35 mph. 

Before I was driving it like I thought was normal for a 1.4 liter 4-cylinder (and most other small 4-cylinders I've driven without a turbo) - at 3000 RPM or above. I still do when I need to keep up with faster traffic, but I feel like I have to push the car _*much*_ less now, even with the AC running.


----------



## obermd (Mar 3, 2012)

XtremeRevolution said:


> I'm liking this Tom Read guy. He seems to prefer to respond to me via phone instead of email, and promptly at that.
> 
> He spoke to two service engineers who owned Chevy Cruzes, and they went out and checked the gap on their cars, then came back. One of them gave him exact specs, and said that they were at .025". Basically, GM now knows there's a big issue when their own engineers can confirm it with their own cars. He told me they have a lot of people working on this issue right now, investigating the assembly line as well as dealing with vendors to determine where the problem is. He mentioned a conference call he had in a few minutes regarding this very issue, so safe to say, my conversations with him have definitely created a great deal of exposure.
> 
> ...


Are you going to add "GM Engineer" 0.025 x 4 to your spreadsheet? Just a thought. I suspect and hope Mr. Read has pulled up CT and read through, and possibly printed, the threads concerning spark plug gap. 




jblackburn said:


> Good news! It's nice when you actually find someone in the chain of bureaucracy that can actually accomplish something, isn't it?
> 
> Reminds me of having to deal with Verizon at times...trying to get someone that actually knows what they're _*doing*_ on the other end of the phone.
> 
> ...


100% agree unless GM Powertrain can provide an engineering answer as to why the North American 1.4T Cruzen should be at 0.028 while the Holden 1.4T Cruzen are at 0.035.


----------



## rbtec (Feb 3, 2012)

Hope a TSB is in the works.


Sent from my Autoguide iPhone app


----------



## Laurie Lou (Apr 26, 2011)

Ok we just got done and 1 was at .025 and 3 were at .026. I took it for a ride and noticed it runs smoother and too soon to judge the pep issue I was having. We reset the miles per gallon indicator and will report back in a day or two.


----------



## Fastalk (Jun 8, 2012)

I just checked my 2012 Cruze LTZ RS with the 1.4 turbo I purchased May 30th. All 4 plugs were .024 gap. re gaped to .035


----------



## bartonmd (Jun 30, 2011)

Just adding to mine... Going from .025 to .035 seems to have yielded a ~5% increase in "commuting" (highway/rural mix) fuel mileage. I could get a pretty consistant 42-42.5mpg on my commute, in the mornings with no A/C running. I'm now getting a pretty consistant 44-45mpg, but I'm running mid-grade since the re-gapping, where I had been running premium.

Mike


----------



## hawkeye (Mar 31, 2012)

I re-gapped about a week ago. I have an '11 Eco automatic that was .025 across the board. I had been experiencing a surging sensation on a cold engine under light throttle on 87 octane gas with a 10% ethanol blend. I had switched to 89 octane 10% blend and didn't notice the surging. I switched to a .034 gap and haven't noticed much of a change since the higher octane seemed to eliminate the surging. I'm debating on whether I should move my gaps down to .028 if it's what's being suggested by GM. How many of the re-gappers have moved it back a bit to the .028?


----------



## XtremeRevolution (Jan 19, 2012)

hawkeye said:


> I re-gapped about a week ago. I have an '11 Eco automatic that was .025 across the board. I had been experiencing a surging sensation on a cold engine under light throttle on 87 octane gas with a 10% ethanol blend. I had switched to 89 octane 10% blend and didn't notice the surging. I switched to a .034 gap and haven't noticed much of a change since the higher octane seemed to eliminate the surging. I'm debating on whether I should move my gaps down to .028 if it's what's being suggested by GM. How many of the re-gappers have moved it back a bit to the .028?


For those on the stock tune, none that I know of. The difference was much too noticeable in both fuel economy and low rpm power to decrease the gap, especially for manual transmissions.

Sent from my Bulletproof_Doubleshot using AutoGuide.Com Free App


----------



## hawkeye (Mar 31, 2012)

I appreciate the work you've gone into the research on this topic. Did the engineer(or whatever the GM guy was) explain why they are suggesting a .028 if people are seeing these results? I'm guessing they had tried different gaps when testing. Is there going to be a durability issue? Misfires? Increased emissions? I'm leaning towards keeping .034 unless I hear their reasoning. Thanks.


----------



## XtremeRevolution (Jan 19, 2012)

70AARCUDA said:


> ...the _wider_ *0.035"* gap is optimum for the engine when it's in *normal aspiration *(NA) operation, while the _tighter_ *0.028"* gap is assurance against 'spark blow out' when the engine is under heavy load and _full_ *turbo* _spool-up _operation.
> 
> ...GM-Powertrain has simply taken the "cautious" path and picked the slightly tighter gap (remember, gap width widens with age & wear!).


The answer is a bit more complicated depending on who you ask. In the GM service manual, the 1.4T calls for the larger gap, not the 1.8. So far, I haven't heard a reason why GM recommends .028 for both. All I'm concerned with is how my car runs, and the verdict is that .035 runs very nicely.

Sent from my Bulletproof_Doubleshot using AutoGuide.Com Free App


----------



## ECRUZ (Mar 6, 2011)

I agree with XR, ever since I regapped my 1.8L plugs to .035, my car is so much more lively, and my freeway merging and acceleration is so much better, not to mention my MPG's has finally leveled out at a nice 34.4 MPG. That is 4.4 MPG's up from"factory gap." So as long as my car keeps running good with no issues, I'm keeping my plugs gapped at .035

Sent from my HTC Rezound


----------



## hawkeye (Mar 31, 2012)

I saw that Vince Trifecta posted on a separate website that the wider gap will put stress on the coils and cause failure--in addition to the blowout of the plugs. He was referring to non-tuned cars, too. Has anyone tried a .030 gap to see if there were any driveablity advantages compared to the stock .025? I'm getting nervous, again, about leaving it up at .034. I don't want to deal with any problems down the road.


----------



## XtremeRevolution (Jan 19, 2012)

hawkeye said:


> I saw that Vince Trifecta posted on a separate website that the wider gap will put stress on the coils and cause failure--in addition to the blowout of the plugs. He was referring to non-tuned cars, too. Has anyone tried a .030 gap to see if there were any driveablity advantages compared to the stock .025? I'm getting nervous, again, about leaving it up at .034. I don't want to deal with any problems down the road.


I argued with him about this quite a bit because his post was full of misleading scare tactics. He never said the wider gap *will *put more stress on *these *coils and cause failures. He said the wider gap *can *put stress on the coils and cause failures. Note the bolded words that make all the difference. The exact same thing is applicable for the spark blowout. I ran .040 for about 800 miles on the stock tune and did not experience spark blowout even once. Again, can, or may is not the same as will or does. His statement was generalized, and as a tuner, I know exactly why he said it; to caution people. 

I would compare this to saying that you may be struck by lightning if you're outside and it rains. Sure, there's the possibility, but it's not quite that simple. My mother in law insists that I shouldn't be playing soccer outside when it rains because I will be struck by lightning. Note the difference there. 

For the time being, the GM service manual still says the gap should be .033-.037. Anything between .028 and .035 will provide an advantage over .025. That is, assuming your plugs are gapped at .025, and not at some random number between .016 and .028. Just read through this thread and you'll see how "all over the place" these gaps are.


----------



## rubiconjp (Feb 10, 2012)

Very good info and investigative works folks. What would we do without internet forums anymore?? 

Sent from my Galaxy Nexus using AutoGuide.Com Free App


----------



## drewcandraw (May 2, 2012)

just checked on mine cause i did notice that shifting from 2nd to 3rd in traffic nearly got me into an accident on multiple occasions...always wondered why it felt boggy so i did what every person does read stuff

checked the gaps and mine were consistent around .025-.026 so i decided to bump it up to .035-.036 accordingly and just finished a drive up and down the street and it feels like my integra...cant report on gas mileage yet since its too early but i was previously getting 42mpg (mostly highway commute,around 65-80mph depending on how i felt).

but i feel the difference in throttle response and i have to say i like it better now


----------



## toydriver00 (May 4, 2011)

Mine were all at .025. I bumped them all up to .028. No noticeable difference..


----------



## Eco (May 13, 2011)

2011 Eco 6MT
After nearly 20K miles.
All of the plugs were .023 across the board exactly.

I suspect GM gapped them so low as to make them the 100,000 mile plug they were meant to be. Even if it burned off all of the Iridium (which some of it may have chipped off when trying to gap those badboys (tried not to)
I regapped them as much as I felt safe to not chip the iridium off
.036, .035, .034, .035

I'll post this in the other thread too, but what I'm going to do since I got this car for my wife and she'll be primarily driving it, I'll see over the next couple of months if the DIC records any improvement or not.

As far as stress on the coils, guys the plugs are supposed to be gapped at .035. These coils that GM has on there are bad arse and .023 is VERY small for a gap, thats what 800 WHP Supra guys gap their plugs to, to get it to spark. On Iridum plugs I'd feel safe gapping to .040 but the problem is all you're doing is opening up the front of the electrode in otherwords the electrode isn't really perpendicular to the plug anymore, so... You'd have to buy a plug that was made out of the box for that gap.
These plugs are definitely made for .025 gap no question, mine just happened to be a bit smaller.


OH *GUYS!* One important thing.
When pulling my coil rail off very gingerly, I noticed inside the boot the springs were probably slightly stretched when being pulled out, and then recoiled back once they popped off the plug behind a lip further up in the boot...
I had to take a tiny screw drive and pop the springs that were pressed up and off to the side catching on that ledge so that they came down and were centered in the coil rail properly.

If you DID NOT do this when you changed your plugs, you need to pull the coil rail off again and make sure all of your springs are centered. I'll make a separate post just to be safe.


----------



## Arcticat (Feb 16, 2012)

All this conversation about which gap is right is becoming somewhat tiresome, does anybody think we will ever get a real answer from GM which is correct? I certainally agree that having 4 plugs all gaped differently is not good, at the very least they should be the same. Looking forward to a final answer to this question.


----------



## Mick (Dec 31, 2011)

Arcticat said:


> All this conversation about spark plug gap is becoming somewhat tiresome


*fixed

Guys do we need 4 threads for this?


----------



## ECRUZ (Mar 6, 2011)

Mick said:


> *fixed
> 
> Guys do we need 4 threads for this?


We don't need 4 threads, but I think at least thus thread should stay open, only because XR was/is gathering information on all the different gap sizes and what the outcome is/was when the plugs were re-gapped...but that is only my 2cents.

Sent from my HTC Rezound


----------



## XtremeRevolution (Jan 19, 2012)

Arcticat said:


> All this conversation about which gap is right is becoming somewhat tiresome, does anybody think we will ever get a real answer from GM which is correct? I certainally agree that having 4 plugs all gaped differently is not good, at the very least they should be the same. Looking forward to a final answer to this question.


We did get a real answer, from two GM service engineers, a few pages back. 



Mick said:


> *fixed
> 
> Guys do we need 4 threads for this?


Yes. This issue is pretty widespread. By widespread, I mean it affects 100% of Cruze owners. This thread is here to get me information regarding what spark plug gaps have been reported (hence the thread title). The "Are your spark plugs gapped correctly" thread has long ago run its course and has exceeded 43 pages. VERY few people are actually going to read the whole thread before posting, but it's there for general discussion anyway. We then have the poll thread asking what fuel economy change came about as a result of the spark plug gaps, which is a related thread, but different in its own right. Lastly, we have the first thread that was created, in the Fuel Economy section, asking what fuel economy effect this had. That thread isn't responded to very frequently so it's safe to say we aren't really using it anymore. 

The existence of this thread has allowed me to work with Tom Read to get some real exposure of the issue over at GM. That alone, in my opinion, is worth having 4 threads about this issue. Getting someone over at GM to scratch their heads and realize there's a problem based on something we told them isn't exactly easy, lol.


----------



## rbtec (Feb 3, 2012)

XtremeRevolution said:


> We did get a real answer, from two GM service engineers, a few pages back.
> 
> 
> 
> ...


Ask GM where the TSB is.


Sent from my Autoguide iPhone app


----------



## XtremeRevolution (Jan 19, 2012)

rbtec said:


> Ask GM where the TSB is.
> 
> 
> Sent from my Autoguide iPhone app


Considering they're still trying to figure out where the issue originates, I don't think that's going to do anyone any good.


----------



## rbtec (Feb 3, 2012)

XtremeRevolution said:


> Considering they're still trying to figure out where the issue originates, I don't think that's going to do anyone any good.


It will give dealerships a way to check gaps under warranty. 


Sent from my Autoguide iPhone app


----------



## XtremeRevolution (Jan 19, 2012)

rbtec said:


> It will give dealerships a way to check gaps under warranty.
> 
> 
> Sent from my Autoguide iPhone app


I'm not questioning that the TSB is necessary or that it would be beneficial in general. I'm just saying, in my talks with Tom, there is no point in me asking him where the TSB is at this point as there simply hasn't been enough time. I've already made it very clear to him that a TSB is needed during a few of our earlier talks, so that people can drive into their dealerships and have their spark plug gaps checked and corrected free of charge. He knows that we've asked for this. I'll follow up with him tomorrow or Wednesday to see what progress they've made in identifying the source of the problem.


----------



## Bohdan (Apr 28, 2012)

Perhaps GM will remain quite on this issue since if they go ahead and post a TSB then many many owners will take there cars to have the plug gap corrected and GM will then have to pay the dealers for there time and this will cost MONEY. They may just leave it as a need to make it so when a person comes to the dealer with a mileage and or poor preformance issue. They may just make it so for the 2013 models after reading this forum.


----------



## rbtec (Feb 3, 2012)

Bohdan said:


> Perhaps GM will remain quite on this issue since if they go ahead and post a TSB then many many owners will take there cars to have the plug gap corrected and GM will then have to pay the dealers for there time and this will cost MONEY. They may just leave it as a need to make it so when a person comes to the dealer with a mileage and or poor preformance issue. They may just make it so for the 2013 models after reading this forum.


I hope this is not the case.


Sent from my Autoguide iPhone app


----------



## rbtec (Feb 3, 2012)

Bohdan said:


> Perhaps GM will remain quite on this issue since if they go ahead and post a TSB then many many owners will take there cars to have the plug gap corrected and GM will then have to pay the dealers for there time and this will cost MONEY. They may just leave it as a need to make it so when a person comes to the dealer with a mileage and or poor preformance issue. They may just make it so for the 2013 models after reading this forum.


I've tried to get a couple dealers to check the plugs, but they say my car is not having misfires or any codes, so they won't check. I just want a TSB to justify the check, without having to say 'I hear from an Internet forum that the gaps are wrong'. 


Sent from my Autoguide iPhone app


----------



## rbtec (Feb 3, 2012)

Bohdan said:


> Perhaps GM will remain quite on this issue since if they go ahead and post a TSB then many many owners will take there cars to have the plug gap corrected and GM will then have to pay the dealers for there time and this will cost MONEY. They may just leave it as a need to make it so when a person comes to the dealer with a mileage and or poor preformance issue. They may just make it so for the 2013 models after reading this forum.


How about simply a PI that states 'If requested by the customer, check and re-gap/replace plugs if necessary'. This way, they will only have to check an extremely small amount of cars.


----------



## Laurie Lou (Apr 26, 2011)

spacedout said:


> looking at your spreadsheet, seems we should also be recording model years also. My 2012 was .019,.024,.025,.024


You mean to tell me this was not just the 2011's??? The 2012 too? Well mine is a 2011 that I reported my numbers already...And yes if we could have just one "live thread" then I will know where to go for updates. Today(for the first time) I had a cruze following me and I was so tempted to tell her about this but thought hers was a 2012... Next tiem If I see another Cruze I'll try to fill them in. This whole thing still amazes me.


----------



## XtremeRevolution (Jan 19, 2012)

Laurie Lou said:


> You mean to tell me this was not just the 2011's??? The 2012 too? Well mine is a 2011 that I reported my numbers already...And yes if we could have just one "live thread" then I will know where to go for updates. Today(for the first time) I had a cruze following me and I was so tempted to tell her about this but thought hers was a 2012... Next tiem If I see another Cruze I'll try to fill them in. This whole thing still amazes me.


Well, it it makes you feel better, I won't be creating any *new *threads, lol. To answer your question though, all Cruzes are still affected. The most recent one we got a report for was manufactured 3-4 weeks ago, so they haven't fixed it yet.


----------



## NYCruze2012 (Jan 16, 2012)

Ok, so I'm going to jump in here also. Finally regapped my plugs as well. 
2012 Cruze Eco 6MT gaps as follows: 19,23,25,18. Gapped all at 30 huge difference in response in the way the car accelerates.


----------



## XtremeRevolution (Jan 19, 2012)

Most recent spreadsheet is attached, containing 88 vehicles.


----------



## taikajm (Jun 21, 2012)

Hey XtremeRevolution,

Do you know if the wrong gapping only afflicts the Lordstown Cruze, or is it universal? Can't see find that info anywhere after going through the threads.

I've got a -12 1.8l euro Cruze, made at the Korean factory. Not being a techhead, figured I'd try to save myself trouble (and money for the tools) by asking first.

Cheers.


----------



## NYCruze2012 (Jan 16, 2012)

taikajm said:


> Hey XtremeRevolution,
> 
> Do you know if the wrong gapping only afflicts the Lordstown Cruze, or is it universal? Can't see find that info anywhere after going through the threads.
> 
> ...


Thats a great question! I am very curious about this also! Maybe we need a split pole of Euro vs. American built

Sent from my DROID3


----------



## XtremeRevolution (Jan 19, 2012)

taikajm said:


> Hey XtremeRevolution,
> 
> Do you know if the wrong gapping only afflicts the Lordstown Cruze, or is it universal? Can't see find that info anywhere after going through the threads.
> 
> ...


I really don't have an answer to this. I would love to know what your gaps measure.

Sent from my Bulletproof_Doubleshot using AutoGuide.Com Free App


----------



## Cavere (Sep 11, 2011)

Mine were all somewhere between .023-.028


Sent from my Autoguide iPhone app


----------



## blacksheep40 (Jun 9, 2012)

2012 eco 6mt. plug gaps were .021, .023, .022, .024. gapped all to .038 and it feels so much better. i dont use ac much but on my test drive i turned it on full and it didnt bog at all even up hill


----------



## blacksheep40 (Jun 9, 2012)

nope, .038... .001 bigger than alldata specs


----------



## CruzeTech (Mar 23, 2012)

Xtreme, you can add me to the list as well when you get a chance. I left my gap specs in the other thread. Most were .010 undergapped.


----------



## XtremeRevolution (Jan 19, 2012)

70AARCUDA said:


> FWIW -- had my wife e-mail GM asking what the gap should be and their response was: _"...0.7mm (0.028"), as written in the Owners Manual..."_


Who at GM did she email, if you don't mind me asking?


----------



## XtremeRevolution (Jan 19, 2012)

Had a long chat with Tom today over the phone. There are quite a few things going on, and a lot of teams on alert. He's working on getting me an email with some more definitive answers, but it's a very complicated process, as he has to get a few teams to sign off on the information before he sends it out. 

Basically, they have Service Engineering, who is there to find the fixes for issues that come up and communicate with the dealers. They then have Manufacturing Engineering, which communicates with the vendors and investigates all of these issues. They then have Product (Engine) Engineering, over in Germany. The entire 1.4L Turbo motor is German engineered, and all real engineering for this motor happens out at the Opel headquarters in Germany. Getting all of those teams to sign off on information that he can give me is not really a simple matter. 

One issue they're currently dealing with is that the spark plug gap should have been specified as a range in the owner's manual. I had the impression talking to him that the 2013 owner's manual will not look the same as the one we have for 2011 and 2012 with regard to these specifications. 

In other news, Tom has invited me for a personal tour of the facility. I think I'll take him up on that offer and drive down there one day this summer.


----------



## obermd (Mar 3, 2012)

Large company => lots of stakeholders. Making changes in any large company takes time. Xtreme, thanks for your efforts on this.


----------



## Hoon (Mar 18, 2012)

After regapping from .025 to the spec of .028, i have noticed absolutely nothing different, lol. 

MPG seems the same, and if it gained any power or response it's certainly not noticeable.


----------



## XtremeRevolution (Jan 19, 2012)

Hoon said:


> After regapping from .025 to the spec of .028, i have noticed absolutely nothing different, lol.
> 
> MPG seems the same, and if it gained any power or response it's certainly not noticeable.


Try .035. There will be a difference there. 

Yours if I remember correctly were more consistent. Most people who notice huge differences have wild variations in spark plug gap, where a combination of both consistency and a larger gap make a big difference.


----------



## rubiconjp (Feb 10, 2012)

Checked this morning, gap was at 0.025 exactly for all four. Regapped to 0.030.

Sent from my Galaxy Nexus using AutoGuide.Com Free App


----------



## cruzers (Dec 13, 2010)

Checked the gap today, all four were .028. I re-gapped to .035 since everybody is either getting better performance or no noticeable difference, nothing to lose I guess.


----------



## vitgia78 (Mar 9, 2011)

@Xtreme: I've re-gapped the spark plugs to 0.038" (my stock is 0.044"). For the low speed, it is better than stock gap, but for middle and high speed, it lacks power in comparison with stock gap, so that I turn back to stock gap. I found in Google that, more wider gap (in limitation) will have more electric.

I think that before regapping the gap, it is necessary to consider which type of spark plug, because some car use different type of spark plugs. If default gap is more than 0.038", there is no need to regap spark plugs, but if default gap is below 0.03", it is better to regap spark plugs. My car uses NGK ZFR6U-11, and I think that 1.4L will use another type.


----------



## obermd (Mar 3, 2012)

vitgia78 said:


> @Xtreme: I've re-gapped the spark plugs to 0.038" (my stock is 0.044"). For the low speed, it is better than stock gap, but for middle and high speed, it lacks power in comparison with stock gap, so that I turn back to stock gap. I found in Google that, more wider gap (in limitation) will have more electric.
> 
> I think that before regapping the gap, it is necessary to consider which type of spark plug, because some car use different type of spark plugs. If default gap is more than 0.038", there is no need to regap spark plugs, but if default gap is below 0.03", it is better to regap spark plugs. My car uses NGK ZFR6U-11, and I think that 1.4L will use another type.


Do you by any chance have the all wheel drive Holden Cruze? That was the only cruze to use 1.1mm spark plug gaps.


----------



## vitgia78 (Mar 9, 2011)

obermd said:


> Do you by any chance have the all wheel drive Holden Cruze? That was the only cruze to use 1.1mm spark plug gaps.


My car is Korean version named Lacetti Premiere CDX 1.6. And Cruze LS 1.6 (MT), Cruze LT 1.8 (MT) and Crzue LTZ 1.8 (AT) version in Vietnam also use that 1.1 mm spark plugs.


----------



## Rescue09 (Oct 6, 2011)

2012 Eco 1.4

All were .025. Now .035


----------



## XtremeRevolution (Jan 19, 2012)

vitgia78 said:


> @Xtreme: I've re-gapped the spark plugs to 0.038" (my stock is 0.044"). For the low speed, it is better than stock gap, but for middle and high speed, it lacks power in comparison with stock gap, so that I turn back to stock gap. I found in Google that, more wider gap (in limitation) will have more electric.
> 
> I think that before regapping the gap, it is necessary to consider which type of spark plug, because some car use different type of spark plugs. If default gap is more than 0.038", there is no need to regap spark plugs, but if default gap is below 0.03", it is better to regap spark plugs. My car uses NGK ZFR6U-11, and I think that 1.4L will use another type.


This spark plug gap this thread was created for only applies to the 1.4L turbo and 1.8L naturally aspirated motors sold in the USA. I would advise you gap back to .044".


----------



## mistereric (Aug 11, 2011)

.24, .25, .25 and .255 from the factory at 24k miles. .35 on all now, and about 2mpg better.


----------



## sheleb1 (Sep 16, 2011)

Regapped from .022, .023, .023, .026 at 14,500km on my 2011 1.4 auto to 0.035". So far notice the engine is a bit more responsive. To early to see if any difference in mpg.

Thank you very much XtremeRevolution for your efforts!

Bill


----------



## AceMan13 (Apr 29, 2012)

I found my gaps to be between .024 & .025. Re-gaped to .035. Both my wife and I feel it's a whole new driving experience. Much better acceleration and pedal response. Very happy about that! Will have to put a few more mile on re-gap before knowing if MPG improves.

2012 LTZ 1.4 Auto 11250 miles.


----------



## ZadeStorm (May 2, 2012)

Just pulled mine into the shop today.2011 Chevy Cruze Ls.Spark Plug Gap when pulled .25(All 4).Had the mechanic gap them to .35.I can go up and down hills like a champ.The driving difference is a completely new experience.Seems to be shifting smoother for some reason.Thanks guys hope my info will help you


----------



## dannylightning (Jun 24, 2012)

2012 cruze eco 1.4T MT i bought the car less than 2 weeks ago, all of my gaps where either at .022 or .025 

after i took the boot off and looked in the boot 3 of the 4 springs in the boot where setting crooked so i got a thin screw driver and lightly tapped the springs and they popped straight and than i re installed the boot, not sure if they usually end up crooked after you take the boot off or not.

i fired up the engine and it seemed to run fine, all the gaps are at 0.35 now i will report back later tonight after i drive the car,


well i figured i better take it out for a spin before i go to work tonight to make sure its running ok, i can now shift sooner at 2k rpm before i had to run it up to at least 2500 rpm before when i shifted there was no power till the motor got up around 1175 rpm and the turbo kicked in..

according to my computer i am now getting around 36 mpg around town i think i was getting around 28mpg around town before the spark plug gap, i have also removed the air filter resonator box which is said to boost up your mpg slightly, tires at 40psi . so between those few things it looks like my MPG just bumped up quite nicely..


----------



## gt_cristian (Apr 7, 2012)

Are there any cons for a wider spark plug gap? How it put more stress on the engine therefore reducing long term engine reliability?


----------



## XtremeRevolution (Jan 19, 2012)

gt_cristian said:


> Are there any cons for a wider spark plug gap? How it put more stress on the engine therefore reducing long term engine reliability?


A larger gap *can* put more stress on the ignition coil, which *can* reduce the longevity of the coil. However, at what gap this starts to happen is unknown. It's a general statement of all ignition coils. 

No failures reported yet.

Sent from my Bulletproof_Doubleshot using AutoGuide.Com Free App


----------



## atdauph (Jun 20, 2012)

Checked mine today...all were .025", regapped to .035.


----------



## jacnnic (Mar 3, 2011)

Mine were set at, .028, .029, .029 & .029


----------



## WisCruze (Jun 5, 2011)

Mine were all .025, I have a 2011 eco mt with 16,000miles


----------



## Atomic (Nov 5, 2011)

I have not yet checked my plugs - that being said, I am making a 425 mile road trip tomorrow morning, and then back on Sunday. This is all the way across Indiana and Illinois with very little elevation change. I am going to measure my MPG (manual calc) when I arrive on the stock plug gaps, and then back again on the regapped plugs and see if there is a meaningful difference. 

I'll report back with my gaps as well.


----------



## backofbeyond (Jul 7, 2012)

2012 LS 1.8 6speed manual
1 on passengers side was .025 all 3 others .024. regapped to somewhere between .031 and .032. This is my first post on this forum. someone posted this was the holden 1.8 spec(.031) and is the highest spec I have seen for a 1.8. I may be better of with .035, eventually. Lots of bog taking off on hills with ac on at .024. very hard to drive.


----------



## Atomic (Nov 5, 2011)

Atomic said:


> I have not yet checked my plugs - that being said, I am making a 425 mile road trip tomorrow morning, and then back on Sunday. This is all the way across Indiana and Illinois with very little elevation change. I am going to measure my MPG (manual calc) when I arrive on the stock plug gaps, and then back again on the regapped plugs and see if there is a meaningful difference.
> 
> I'll report back with my gaps as well.


Just wanted to provide an update.

1st trip - 452 miles on 12.5 gallons = 36.1mpg
Weather conditions were 100 degrees with around 40% humidity and a 5-7mph headwind.
AC was ON the entire trip, cruise control at 70mph.

Spark plug gaps were found to be .024, .024, .027, .026

Regapped plugs to .033

~~~~~~

2nd trip - 452 miles on 13.0 gallons = 34.7mpg
Weather conditions were average temp around 80, humidity about 60%, some rain, winds were a strong headwind for first half of trip, then variable the second half.
AC was ON for half the trip, OFF for the second half, with cruise set at 70mph.

This is not scientific nor indisputable evidence one way or the other, but given the weather variables, *I'd call the spark plug gaps having a noticeable effect on MPG unlikely at best*, whether it be positive or negative. I use only 93 octane in the car (10% ethanol) as well.


----------



## XtremeRevolution (Jan 19, 2012)

Atomic said:


> Just wanted to provide an update.
> 
> 1st trip - 452 miles on 12.5 gallons = 36.1mpg
> Weather conditions were 100 degrees with around 40% humidity and a 5-7mph headwind.
> ...


As I mentioned in the other thread you posted this, you will need to run several complete tanks of gas to accurately gauge what difference this makes _for you_. The DIC is far too inaccurate to use to measure fuel economy changes with modifications.


----------



## Atomic (Nov 5, 2011)

As I similarly replied in the other thread, these numbers were calculated at the pump, not using the DIC. I said they are not scientific nor indisputable; sample is far too small. However, this is still data that is more accurate than multiple tanks of gas in variable stop and go traffic and city driving that people experience in their daily commutes and attempt to derive results from.


----------



## oshia86 (May 29, 2011)

Did mine Saturday. They were all under .03. Gapped them and did the intake mod at the same time. Smoothed out starting just a hair.


----------



## Curoudo (Jun 15, 2011)

2011 1.4L LT
0.020, 0.020, 0.023, 0.022
All changed to 0.035


----------



## longmw (Jun 22, 2011)

2011 LTZ with 1.4T

0.025 0.023 0.023 0.025

re-set to user manual 0.028


----------



## Beachernaut (Mar 27, 2012)

I really need to visit this place more than every week or month.

XR- For the sake of you having accurate information I'll expand on my "varied between .024 and .026" in the other thread.

2012 Eco M6 stock with intake resonator removed.
1 plug at .024, 1 plug at .025, and 2 at .026

My low RPM hesitation that went away with the regap to .035 is now back. However, I believe that's because of the hot weather combined with running AC, and nothing do do with the gap

Also, my MPG has gone up since the regap, but I can't say for sure why. Could be a minor change in driving habit I didn't notice, the fact that my car barely has 2600 miles, etc.


----------



## XtremeRevolution (Jan 19, 2012)

****, even I noticed hesitation the past couple of weeks.

However, the conditions were pretty...taxing. For the last 2 tanks of gas, I had 5 people in my car and my sound system, (I'd estimate ~1000 pounds of extra weight) A/C on full blast, and 95-105+ degree temperatures. I learned to keep my revs above 2000 to avoid that hesitation, especially when starting from a stop.

Sent from my Bulletproof_Doubleshot using AutoGuide.Com Free App


----------



## Beachernaut (Mar 27, 2012)

Yup, with the AC on my car is a dog below 1800rpm.


----------



## Kinmartin0789 (Feb 18, 2011)

has anyone read this thread from Vince at trifecta? 

So... What exactly is the spark plug gap supposed to be on the 1.4 turbo?? - 1.4L Turbo (LUJ, LUV) and 1.6L Turbo (LLU) - WOT-Tuning.com

what are your guy's thoughts? i want to check to make sure my gaps are correct on my new car but it seems like it should be .028 not .035.


----------



## XtremeRevolution (Jan 19, 2012)

Kinmartin0789 said:


> has anyone read this thread from Vince at trifecta?
> 
> So... What exactly is the spark plug gap supposed to be on the 1.4 turbo?? - 1.4L Turbo (LUJ, LUV) and 1.6L Turbo (LLU) - WOT-Tuning.com
> 
> what are your guy's thoughts? i want to check to make sure my gaps are correct on my new car but it seems like it should be .028 not .035.


I've already gone over that post in this thread. Read back several pages and you'll find it. In all honesty, it's more important that your gaps are consistent than what the exact gap size is within either of those specifications.


----------



## obermd (Mar 3, 2012)

Kinmartin0789 said:


> has anyone read this thread from Vince at trifecta?
> 
> So... What exactly is the spark plug gap supposed to be on the 1.4 turbo?? - 1.4L Turbo (LUJ, LUV) and 1.6L Turbo (LLU) - WOT-Tuning.com
> 
> what are your guy's thoughts? i want to check to make sure my gaps are correct on my new car but it seems like it should be .028 not .035.


In a nutshell, if you have a tune, gap to 0.028". Otherwise the current GM Service manual says 0.035" +/- 0.05mm. GM is working on this issue and may come back and say 0.028" for all North American Cruzen, however.


----------



## XtremeRevolution (Jan 19, 2012)

obermd said:


> In a nutshell, if you have a tune, gap to 0.028". Otherwise the current GM Service manual says 0.035" +/- 0.05mm. GM is working on this issue and may come back and say 0.028" for all North American Cruzen, however.


I completely forgot to post Tom's official statement (backed by both GM Service Engineering in Detroit and GM Product Engineering in Germany). Here it is:



> Hello Andrei,
> 
> In a follow-up to your question regarding the correct spark plug gap for the Cruze 1.4L turbo engine I worked with our product and service engineering teams to get these answers back to you. Feel free to pass this information on to others.
> 
> ...


Of course, they also don't recommend that we install Trifecta tunes, but those who have will more than justify their decision. I'd like to highlight his carefully chosen words:



> *potential *negative effects


I would certainly not go even close to the .6 lower limit GM is now recommending. .7mm or .028" is the lowest I would go on this car. I would not go any higher than .035.


----------



## Kinmartin0789 (Feb 18, 2011)

i apologize, i was googling random stuff and came across it. i think i will gap to .028 just to be safe


----------



## MyShibbyEco (Jan 21, 2012)

Did mine over the weekend. The following were my previous specs. All are 0.089mm now.

0.022", 0.020", 0.023", 0.022"


----------



## silverls (Nov 12, 2011)

2012 1.8 liter. Finally did mine. 0.025, 0.026, 0.026, 0.026. Fairly consistent. Regapped to 0.034 to try it out.

Sent from my DROID BIONIC using AutoGuide.Com Free App


----------



## SkullCruzeRS (Nov 3, 2011)

Just got done with re-gaping mine, factor results were the following from left to right:

0.025
0.022
0.024
0.024

Not horribly bad as far as consistency compared to others results. Re-gaped them to 0.028 as I plan on getting the tune sometime down the road.


----------



## bh04 (Aug 5, 2011)

I can't remember if I posted in here or not. But mine were as follows from left to right:

0.019
0.022
0.024
0.022
Regapped all of mine to 0.028 as I am tuned.


----------



## sog805 (Jun 23, 2011)

All of mine were right around .019 to .022. I regapped them all to .33 and a drive around the block with full blown AC seemed to run slightly smoother.


----------



## Chris2298 (Aug 1, 2012)

My 2012 1.4 Eco 6spd was born on 6/11... It has 40440 miles... All plugs at .28 except #2 (left to right), it was .26... Now they're all at .35... It's been running rough lately (since it went out of warranty), hope this fixes it... Probably could use new ones, do you guys recommend sticking with the stock plug?


----------



## XtremeRevolution (Jan 19, 2012)

Chris2298 said:


> My 2012 1.4 Eco 6spd was born on 6/11... It has 40440 miles... All plugs at .28 except #2 (left to right), it was .26... Now they're all at .35... It's been running rough lately (since it went out of warranty), hope this fixes it... Probably could use new ones, do you guys recommend sticking with the stock plug?


You said you have over 40k miles? How did you drive that many miles on a 2012???

Did you pull the battery cable after re-gapping the plugs?


----------



## Vetterin (Mar 27, 2011)

About 2-3 weeks ago I regapped mine back down to .028 and the car turned into a dog! No pick-up at all under 2500 rpm's. This morning before I left for work I upped the gap to .033 and the difference in low rpm power is once again quite noticeable.


----------



## Chris2298 (Aug 1, 2012)

I drive A LOT for work... and I did not, should I?


----------



## XtremeRevolution (Jan 19, 2012)

Chris2298 said:


> I drive A LOT for work... and I did not, should I?


Definitely yes.


----------



## Chris2298 (Aug 1, 2012)

I pulled the (-) cable before going out. Great improvement! Thanks for the heads up! I'm going to do the air box mod next. Has anyone had any issues in wet conditions doing this?


----------



## XtremeRevolution (Jan 19, 2012)

Chris2298 said:


> I pulled the (-) cable before going out. Great improvement! Thanks for the heads up! I'm going to do the air box mod next. Has anyone had any issues in wet conditions doing this?


You'd have to be fording rivers 2 feet deep in order for any consequential amount of water to get sucked in through there.


----------



## Cips (May 21, 2012)

My plugs (2011) were .029.


----------



## MonkeyRench (Feb 10, 2012)

Got car back today and had them check for spark plug gaps because of MPG issues. They found all of them to be in spec at .028 which is what they call for. EXPECT FOR ONE. It was gapped at .090. YUP I had the same question. Why not a misfire? Of course the usual hesitation was there but everyone has that. They didn't have an answer but the car is getting better MPG on the DIC just one way to work which is about 50 miles. One down side, it feels slower than before.. Gonna live with it because it's a lease but if I bought one, I'd have to have a tune. Which the dealer said the GM engineers couldn't tune the TCM/ECM to stop the hesitation without the tranny being "reliable".. They said a lot of customers are really complaining about almost getting creamed by traffic because of the "lag".


----------



## MonkeyRench (Feb 10, 2012)

Another thing about the MPG. Call this a conspiracy theroy but as soon as my oil change light came on my MPG on the DIC was terrible..Maybe that's a way to get people into the shop for an oil change. Who knows? I was going to reset it and see if the MPG went back up but I wasn't that interested in waiting for an oil change since it was already at the dealer.


----------



## XtremeRevolution (Jan 19, 2012)

.090?!?! Wow. Hesitation you say? Try to bump those up to at least .030, preferably .035 and see if it goes away.

Sent from my Bulletproof_Doubleshot using AutoGuide.Com Free App


----------



## MonkeyRench (Feb 10, 2012)

I'm not going to mess with it. It's too hot outside here and I have enough crap to work on. lol. I'll disconnect the battery for a while and let it relearn but I'm not gonna take the plugs out. Although some have stated good results. By hesitation I meant the typical delay between the time I hit the gas and the time the car takes off. I never had a misfire or a spudder from the plug being gapped that big which is crazy to me.


----------



## skiisme753 (Jun 21, 2012)

2011 LTZ automatic were all .029. regapped to .035


----------



## hawkeye (Mar 31, 2012)

Just in case anyone else disconnects the battery cable after the re-gap: It's not just the clock to reset, you need to re-activate the 1 up power window switch. It's in the manual. Basically you turn the ignition to on, put the window down, put it up and hold the switch for atleast two seconds after it's up.


----------



## Testadura (Jul 16, 2012)

2012 1LT 2.4
Factory Gap: .024. .025, .025, .024
Re-gapped to: .029


----------



## XtremeRevolution (Jan 19, 2012)

hawkeye said:


> Just in case anyone else disconnects the battery cable after the re-gap: It's not just the clock to reset, you need to re-activate the 1 up power window switch. It's in the manual. Basically you turn the ignition to on, put the window down, put it up and hold the switch for atleast two seconds after it's up.


What is this 1-up power window switch you're speaking of?


----------



## RedChevy (May 22, 2011)

I just re-gapped the plugs in my 2011 1LT 1.4T with A/T.
I couldn't find my slide gap tool so I had to use my ring gapper (which makes it hard to be exact).
The .025 ring slid through snugly on all 4 plugs so I'll say they were all .025.
I opened up all 4 plugs to where the .032 ring slid through snugly.
I'll let you know later if it feels better.


Update: After about 10 miles of driving I'm not sure it's any better but it's certainly not any worse.


----------



## hawkeye (Mar 31, 2012)

I guess I should have worded it better. The ECO has a one-touch up feature for the driver's front window. When you pull it all the way back, the window will close without having to hold the switch. When you disconnect the battery cable, it disables the one-touch up feature. The manual mentions this. I just happened to go to the car wash the day after disconnecting the cable and pulled the switch, but it stopped moving as soon as I took my finger off. I looked in the manual and it spelled out the re-programming procedure.


----------



## AceMan13 (Apr 29, 2012)

XtremeRevolution said:


> Definitely yes.


Missed the post about cable disconnect. Could you elaborate? I have put 7K since re-gap and car still has great response.


----------



## hondo84 (Dec 14, 2011)

2012 cruze turbo spark plug gap was .027 to.029 on plugs


----------



## woz (Feb 20, 2012)

when i removed my plugs from a 2012 rs lt2 they were at .019, .021, .022, .020, i re gaped at .035 and increased mileage by almost 3 mpg with way more low end power and smoother idle


----------



## cas2 (Jul 8, 2012)

Is There Any Indication yet the chevy dealer should re-gap my plugs ? I don't feel comfortable doing this procees myself.


----------



## XtremeRevolution (Jan 19, 2012)

woz said:


> when i removed my plugs from a 2012 rs lt2 they were at .019, .021, .022, .020, i re gaped at .035 and increased mileage by almost 3 mpg with way more low end power and smoother idle


WOW. that's universally very low. I have no doubt you got 3mpg out of this!



cas2 said:


> Is There Any Indication yet the chevy dealer should re-gap my plugs ? I don't feel comfortable doing this procees myself.


There is no indication that dealers will do anything here. It's a fairly simple process. Do you have anyone on the board located nearby? I'm sure someone will be willing to do it for you. It's really a very simple job. There is a how-to thread in the how-to section describing exactly what is needed to perform this. Your plugs may be ok, or they may be like woz's plugs, which were in desperate need of correcting. 



hondo84 said:


> 2012 cruze turbo spark plug gap was .027 to.029 on plugs


That's not that bad. I'd say those are pretty good plugs to get from the factory. 

By the way guys, welcome to CruzeTalk. If you haven't yet posted a thread in the introductions section to introduce yourselves, please do. We'd love to see your cars and get to know you more.


----------



## sciphi (Aug 26, 2011)

Mine were at about 0.021-0.024. I went to 0.030, but got blowout after a few thousand miles (note I'm tuned too, and it only happened at about 20-23 PSI while in Sport mode), so they went back down to 0.027 the other day. I haven't driven it yet since we've been taking our other car places.


----------



## toxaris (Mar 19, 2011)

*2011 Cruze 1.8 l AT. Spark plugs gaps and poor customer service from GM dealer*

2011 Cruze 1.8 l AT. Spark plugs gaps from left to right: 0.024, 0.025, 0.026, and 0.024. Re-gapped all at 0.029. There is definitely some improvement in better power especially at low rpm and it appears better mileage (I get slightly lower averages on the same route in the same traffic conditions).

Few weeks ago I took my car for an oil change and I complained about higher than normal engine vibration especially when engine was hot and/ or the A/C on. The dealer couldn’t find anything wrong (they just check for error codes and didn’t find any stored) and they try to explain that this is the nature of the car when the AC is on (explanation which I don’t buy). 

Two weeks ago I took the car for the latest recall and I asked the dealer to check the Spark plugs gaps explaining sluggish response at low rpm and the fact that I read on the forum that most of the people found incorrect gaps. The answer was very disappointing and clearly poor customer service:
- Oh, yeah, those guys on the forum who like to troubleshoot themselves (ironic tone)
- Because would be the second time I complain about non-existing problems I can be charged $115 for checking the Spark plugs gaps. I pointed out about my first complain that the fact they didn’t find the root cause it doesn’t mean the problem doesn’t exist and $115 for 15- 20 min job is ridiculous.
- Eventually I got a tech to drive the car with me and he decided there was no problem: all Cruze’s drive the same and he blamed the AT. He also told me that even if the gaps were less than the specs it shouldn’t be a problem as the computer would adjust.
- They also told me there was no TB from GM to check the Spark plugs gaps

Therefore I ended up re-gapping myself. If anyone from GM Customer Service reads these posting, I am very unhappy about how I was treated by the dealer and the fact that GM doesn’t react to come up with a TB. It appears that re-gaping the spark plugs didn’t improve anything related to the vibration so this problem is still not solved.


----------



## jblackburn (Apr 14, 2012)

toxaris said:


> 2011 Cruze 1.8 l AT. Spark plugs gaps from left to right: 0.024, 0.025, 0.026, and 0.024. Re-gapped all at 0.029. There is definitely some improvement in better power especially at low rpm and it appears better mileage (I get slightly lower averages on the same route in the same traffic conditions).
> 
> Few weeks ago I took my car for an oil change and I complained about higher than normal engine vibration especially when engine was hot and/ or the A/C on. The dealer couldn’t find anything wrong (they just check for error codes and didn’t find any stored) and they try to explain that this is the nature of the car when the AC is on (explanation which I don’t buy).
> 
> ...


Have you tried 89 octane? It's a different engine, but my 1.4T vibrates A LOT with the AC on running 87 octane. After re-gapping and running 89, idle is much, much smoother.


----------



## toxaris (Mar 19, 2011)

Yes, I tried 89 and the vibration is at a more acceptable level, but it is still there. I still don't understand why it is worse when the engine is hot


----------



## steamguy14 (Jul 26, 2011)

2012 Cruze 1LT - .024, .021, .026, .025


----------



## smoove87 (Jul 9, 2012)

2012 Cruze 1LT AT - .024, .025, .025, .027


----------



## Chevy Customer Care (Oct 29, 2011)

toxaris said:


> 2011 Cruze 1.8 l AT. Spark plugs gaps from left to right: 0.024, 0.025, 0.026, and 0.024. Re-gapped all at 0.029. There is definitely some improvement in better power especially at low rpm and it appears better mileage (I get slightly lower averages on the same route in the same traffic conditions).
> 
> Few weeks ago I took my car for an oil change and I complained about higher than normal engine vibration especially when engine was hot and/ or the A/C on. The dealer couldn’t find anything wrong (they just check for error codes and didn’t find any stored) and they try to explain that this is the nature of the car when the AC is on (explanation which I don’t buy).
> 
> ...




toxaris,
I would like to apologize for the issues that have you have experienced with your dealer as well as your Cruze. I understand that this can be frustrating to deal with. Have you been in contact with GM of Canada? If you have not I would suggest that you contact them and explain to them your concerns. You can contact them at 800-263-3777 Monday-Friday 7:30am - 11:30pm or Saturday 7:30am - 6:00 EST. If you have been in contact with them please let me know what progress you made with them. I do look forward to hearing back from you.
Thank you,
Stacy Chevrolet Customer Service


----------



## tjtenor4 (Mar 21, 2012)

I'm kinda late to this party, but I just did mine (2012 Eco Manual trans w/1.4L Turbo). Gaps were either 0.024 or 0.025 on all 4 plugs. Re-gapped them all to 0.030 all around. Haven't had the chance to try driving it since, I will update here if there are any significant changes. I'm in the middle of a tank so probably won't notice fuel economy changes until after the next tank.


----------



## Sk8ermarc (Apr 10, 2012)

Just done mine, a little late too, they were .025, .024, .024, .024 from left to right. Regapped to .029. I don't want to go higher because I plan to tune soon. Job took me only 15 minutes!


----------



## XtremeRevolution (Jan 19, 2012)

My impression is that the spark plug gaps have effectively stabilized since my discussion with Tom. My guess is whatever issue there was has been corrected. 

If anyone decides to post any new gap, please check your door jamb and post your car's build date. If I see any relatively new Cruzes (especially 2013 models) with out of spec spark plug gaps, I'm going to have to contact Tom and the Flint Engine Plant to have them investigate the issue again.


----------



## Big Grouch (Apr 16, 2012)

2012 Cruze 1LT, build date 11/11. Three at .025, one at .020. All now at .030, not driven yet, so no reports.


----------



## steamguy14 (Jul 26, 2011)

steamguy14 said:


> 2012 Cruze 1LT - .024, .021, .026, .025


I reset all of my plugs to .035 the day I posted my original gaps. Since then, I have done a bit of around town driving and went on a 600 mile road trip. The gas mileage was just above sticker for the trip average and the engine runs perfectly.


----------



## Arctic Cat ZRT (Mar 19, 2012)

Well this weekend I will be home some college, and I am going to be checking the gaps, hopefully if I have time! Now as I was reading through and the GM spec is .35 gap, I also see alot of people going to .30 gap. Which on should I choose? I have the resonator disconnected, and planning to put a K&N filter drop in. I do not have a plan for a tune in the near future.


----------



## jblackburn (Apr 14, 2012)

Arctic Cat ZRT said:


> Well this weekend I will be home some college, and I am going to be checking the gaps, hopefully if I have time! Now as I was reading through and the GM spec is .35 gap, I also see alot of people going to .30 gap. Which on should I choose? I have the resonator disconnected, and planning to put a K&N filter drop in. I do not have a plan for a tune in the near future.


.35 works great for me. Never had blow-out on my stock car.


----------



## izzyizz (Mar 11, 2012)

Left to right... 0.025, 0.025, 0.023, and 0.025 put them to.029 and car has no more jerking from a dead stop and the car shifts like Ithink it should. Drives like an automatic not a manual which is what I was complainingto the dealer about and it was just a matter of adjusting the gaps of theplugs.
BRAVO, BRAVO :eusa_clap:
LTZ 05/2011 
Miles 22715 tune


----------



## l-eater (Aug 6, 2012)

I gapped mine this weekend. 3 of them were at .024 and the other was .025 I set them all at .030 I have driven approx 100 miles since, cant tell any difference so far.


----------



## Starks8 (Jul 20, 2011)

l-eater said:


> I gapped mine this weekend. 3 of them were at .024 and the other was .025 I set them all at .030 I have driven approx 100 miles since, cant tell any difference so far.


Ive heard you have to disconnect the battery either before or after regapping the spark plugs.


----------



## XtremeRevolution (Jan 19, 2012)

Starks8 said:


> Ive heard you have to disconnect the battery either before or after regapping the spark plugs.


Correct. 

Also, the difference is mostly noticeable at the lower RPMs and under load, such as when A/C is on. Manual transmission owners have noticed much more of a difference than Automatic transmission owners, as we can take off from a start and spend a great deal of our time under 1,500 RPM, while the Automatics will be higher than that as a result of the torque converter.


----------



## Adrian1989 (Sep 2, 2012)

My 2012 Cruze Eco MT: .026" .026" .025" .024"

Mom's 2011 Cruze LT Auto: .025" .0255" .026" .0255"


----------



## sheleb1 (Sep 16, 2011)

XtremeRevolution said:


> Correct.
> 
> Also, the difference is mostly noticeable at the lower RPMs and under load, such as when A/C is on. Manual transmission owners have noticed much more of a difference than Automatic transmission owners, as we can take off from a start and spend a great deal of our time under 1,500 RPM, while the Automatics will be higher than that as a result of the torque converter.


I changed the gaps approx 1500km ago and didn't know about having to disconnected the battery also.
Would it still be worthwhile? And if so, what difference would it make?? (So the car can 're-learn' how to run more efficiently?)


----------



## izzyizz (Mar 11, 2012)

sheleb1 said:


> I changed the gaps approx 1500km ago and didn't know about having to disconnected the battery also.
> Would it still be worthwhile? And if so, what difference would it make?? (So the car can 're-learn' how to run more efficiently?)


I was just wondering the same thing. I didn’t disconnect my batterywhen I changed the gaps on my plugs but the car is running better than ever.


----------



## sheleb1 (Sep 16, 2011)

Anyone have an answer or opinion?
Would it still be of benifit for those who didn't disconnect the battery during the re-gap to do it after putting on a couple thousand km or miles with the re-gap?

Thanks.


----------



## XtremeRevolution (Jan 19, 2012)

sheleb1 said:


> Anyone have an answer or opinion?
> Would it still be of benifit for those who didn't disconnect the battery during the re-gap to do it after putting on a couple thousand km or miles with the re-gap?
> 
> Thanks.


It wouldn't hurt, but if you've been driving a while, the car's computer will have adjusted the fuel trims by now.


----------



## ECRUZ (Mar 6, 2011)

sheleb1 said:


> Anyone have an answer or opinion?
> Would it still be of benifit for those who didn't disconnect the battery during the re-gap to do it after putting on a couple thousand km or miles with the re-gap?
> 
> Thanks.


The whole point of disconnecting the battery is so the ECU can recalibrate itself to the change. Is it still a benefit, probably, but I assume its more of a benefit if you were to recalibrate your ECU. Someone please correct me if I'm wrong.

Sent from my DROID RAZR using AutoGuide App


----------



## XtremeRevolution (Jan 19, 2012)

ECRUZ said:


> The whole point of disconnecting the battery is so the ECU can recalibrate itself to the change. Is it still a benefit, probably, but I assume its more of a benefit if you were to recalibrate your ECU. Someone please correct me if I'm wrong.
> 
> Sent from my DROID RAZR using AutoGuide App


The calibration is based on fuel trims. Long term fuel trims take a while to change and are calculated over a significant mileage. At the time of your spark plug gap change, your computer is calibrated to run off of the fuel trims it knew based on the previous gap size. The difference gap size will start to provide the computer with new data that will slowly change the long term fuel trims. It takes a good number of miles for the computer to get used to the new information, whereas if you disconnect the battery right when you change the plugs, the computer can start fresh and learn the fuel trims based on the new gap without having to take time to get used to it based on the previous gap.


----------



## ECRUZ (Mar 6, 2011)

XtremeRevolution said:


> The calibration is based on fuel trims. Long term fuel trims take a while to change and are calculated over a significant mileage. At the time of your spark plug gap change, your computer is calibrated to run off of the fuel trims it knew based on the previous gap size. The difference gap size will start to provide the computer with new data that will slowly change the long term fuel trims. It takes a good number of miles for the computer to get used to the new information, whereas if you disconnect the battery right when you change the plugs, the computer can start fresh and learn the fuel trims based on the new gap without having to take time to get used to it based on the previous gap.


Thanks Xtreme, appreciate the help as well as the knowledge.

Sent from my DROID RAZR using AutoGuide App


----------



## flynryan87 (Sep 12, 2012)

my car 2012 cruze eco mt6 all the plugs were gapped at 24


----------



## ctrider (Sep 9, 2012)

I just checked mine today and 3 were at 25, one was 23. That's on a 2013 ECO.

EDIT:

Oh and I did disconnect the neg terminal after, while I did other things to it.


----------



## Sunline Fan (Jul 29, 2012)

Just did this tonight. All four of my near-virgin (910 miles) plugs were .025", quite dirty already, and lacking any type of antiseize. 2012 1.4L, car built 2/23/12. I re-gapped to .030", cleaned them, and reinstalled with antiseize. I took it for a quick spin, and it does seem to have MUCH better pickup! It was a little disappointing before, which is why I kept it in manual mode most of the time in order to get some revs when in traffic. I like the manual mode and will probably continue to use it all the time, but it will perform much better!

This car just continues to impress me!

Plugs before:









Plugs after: (sorry, put one in already so the pic is just of three)


----------



## XtremeRevolution (Jan 19, 2012)

The lack of antisieze was intentional. At 18lb-ft without antisieze from the factory, it is very unlikely that they wold sieze up over the course of their usable life.

Using antisieze on these is not necessary.

I'm glad you noticed a difference though. 

Sent from my Bulletproof_Doubleshot using AutoGuide.Com Free App


----------



## jaszypoo (Dec 1, 2011)

Going to pick up a plug gapper in the near future. .029" is the recommended for tuned vehicles right?


----------



## XtremeRevolution (Jan 19, 2012)

jaszypoo said:


> Going to pick up a plug gapper in the near future. .029" is the recommended for tuned vehicles right?


.027-.029, yes. 

Sent from my Bulletproof_Doubleshot using AutoGuide.Com Free App


----------



## Sunline Fan (Jul 29, 2012)

Maybe it's just coincidence, but I was very impressed with my Cruze commuting today, more than ever. I don't know whether to attribute it to the plug gaps, intake resonator tube delete, or both, but I'm thinking mostly plugs. I was able to merge onto the highway today in fifth gear without having to downshift at all, which was required before because it bogged down so much. You could just tell the engine kinda sputtered a little before and just didn't have much go. Now it's got immediate, throaty response without needing to rev more.

Best of all, since I filled up last night, I averaged 38 mpg on my trip in today, and 35 average for the day! Granted that's just according to the computer, so I'll know more when it's time to fill up again, but the best I did before in the same situation was about 35/32. As a matter of fact, the highest the computer has read for longer term was around 34/35.

I have to say, if this all stays like this and I continue to get better mileage to boot, all for a mod that cost nothing, THAT'S JUST AWESOME!!!


----------



## Starks8 (Jul 20, 2011)

Sunline Fan said:


> Just did this tonight. All four of my near-virgin (910 miles) plugs were .025", quite dirty already, and lacking any type of antiseize. 2012 1.4L, car built 2/23/12. I re-gapped to .030", cleaned them, and reinstalled with antiseize. I took it for a quick spin, and it does seem to have MUCH better pickup! It was a little disappointing before, which is why I kept it in manual mode most of the time in order to get some revs when in traffic. I like the manual mode and will probably continue to use it all the time, but it will perform much better!
> 
> This car just continues to impress me!
> 
> ...



How did you clean them?


----------



## Sunline Fan (Jul 29, 2012)

Starks8 said:


> How did you clean them?


Hey Chris,

Carefully, with a small wire brush. I didn't do the point though, just the (dirty) threads and tip. The after picture has the anti-seize on it though, so that's why it doesn't look perfectly clean.


----------



## Starks8 (Jul 20, 2011)

Sunline Fan said:


> Hey Chris,
> 
> Carefully, with a small wire brush. I didn't do the point though, just the (dirty) threads and tip. The after picture has the anti-seize on it though, so that's why it doesn't look perfectly clean.


Got cha, thanks!


----------



## WM.Mike (Apr 1, 2012)

I just pulled my plugs and found the gaps at a pretty consistent 0.025" to 0.026". They were similarly dirty to how Sunline Fan's looked in the before picture.

I gapped them to 0.032" and will lightly wire brush them before reinstalling. My car is a 2012 Cruze Eco, 1.4T with 6-speed manual trans, and I have about 13k miles on it. Airbox mod only, no tune. Hopefully this gap is good for now, but I'll drop it down if I end up getting the Trifecta. I haven't driven it yet, but will report back if there's a noticeable change.


----------



## My Cruze Eco (Oct 22, 2011)

I pulled my plugs today with 16K miles on them the numbers were 0.025",.0.022,0.024,0.023. I set them all to.029.
2011 Eco 1.4.


----------



## HisandHers (Aug 18, 2012)

I checked mine today and they were not bad but not right.From left to right the numbers were 0.025,0.028,0.028,0.026.I regapped them to 0.031 and took it for a drive.It seems to accelerate a little smoother now.

This is a 2012 1.4 with a build date of 7/12.


----------



## Convict (Sep 19, 2012)

2012 Eco M/T 
left to right
.026
.025
.025
.025

Now at .035 and runs smoother.


----------



## titan2782 (Nov 4, 2011)

2011 Eco MT with Trifecta tune
All were 0.025

Bumped to 0.028. There is less bogging off the line in 1st. The car feels different, like it might be stronger, but it could also be my imagination. Might be a little crisper. When I push the pedal it seems to respond quicker. No idea why bigger gap would help that, but what ever. 

I ran it up to 4500 rpm WOT and didn't notice any problems like blow out. Then again, my tune isn't working like it should be. Will run it for a few more days and see what happens.


----------



## shadows69 (Oct 9, 2012)

2012 1.4t LT
.023 .025 .025 .023
All changed to .035 and running 87 octane. Reaching 50 miles per gal. On the highway. Only other mod is the remove of the air duct. Car has only 300 miles on it, still in break in period. Very happy I bought a Cruze!


----------



## Jaycruze (Jul 11, 2011)

Finally got around to checking mine.
from left to right they were:
2011 LS
.025 .019 .026 .020

I regapped the first one to .028 and decided to take it in and let the dealer do the rest, I'm afraid I'm going to break one! those things are harder to bend then I thought they would be!.

there must be some technique I'm missing, When I did the first one I ended up making it way over gap and then I had to push it back to 28.

The gap tool i was using is one of those types that flip out like a swiss army knife.


----------



## titan2782 (Nov 4, 2011)

shadows69 said:


> 2012 1.4t LT
> .023 .025 .025 .023
> All changed to .035 and running 87 octane. Reaching 50 miles per gal. On the highway. Only other mod is the remove of the air duct. Car has only 300 miles on it, still in break in period. Very happy I bought a Cruze!


What altitude are you? 50 mpg's on 87 @ 0.035 seems dangerous. You should do a few hard runs and then pull the plugs and examine them. Had mine at 0.028 and they turned white (too hot). Moved them to 0.022.


----------



## XtremeRevolution (Jan 19, 2012)

titan2782 said:


> What altitude are you? 50 mpg's on 87 @ 0.035 seems dangerous. You should do a few hard runs and then pull the plugs and examine them. Had mine at 0.028 and they turned white (too hot). Moved them to 0.022.


Don't you also have a tune? That generally makes a pretty big difference...

.022" is _significantly under _the recommended GM spec of .0235.


----------



## shadows69 (Oct 9, 2012)

Sorry made a typo should be 35 mph at .035 gap. 1.4 Turbo 2012. What is the gap that it should be? Mine is all stock no mods, I keep reading different gaps on here.


----------



## titan2782 (Nov 4, 2011)

XtremeRevolution said:


> Don't you also have a tune? That generally makes a pretty big difference...
> 
> .022" is _significantly under _the recommended GM spec of .0235.


I would agree that having a tune is more likely to cause problems with higher gaps, but if 0.022 is "significantly" under then what do you consider 0.035? On 91/93 you're probably not going to see any problems (this is me assuming you drive more like a grandma and less like an a-hole), but 87? 

I would say if his driving style includes a heavy foot, he should check and report back. Has anyone who over gaped pulled their plugs after some hard driving to see what they look like?


----------



## XtremeRevolution (Jan 19, 2012)

titan2782 said:


> I would agree that having a tune is more likely to cause problems with higher gaps, but if 0.022 is "significantly" under then what do you consider 0.035? On 91/93 you're probably not going to see any problems (this is me assuming you drive more like a grandma and less like an a-hole), but 87?
> 
> I would say if his driving style includes a heavy foot, he should check and report back. Has anyone who over gaped pulled their plugs after some hard driving to see what they look like?


I'll share my experiences, for what it may be worth. I didn't pull mine after some heavy driving, but I have been pulling them periodically and have not noticed an issue. I have run the following gaps:

.025 (stock)
.030 
.033
.035
.038
.040

I did not notice any improvements at .038 or .040 over .035, but did notice some spark blowout at .040 under specific conditions, occasionally. At 15k miles, my spark plugs show no signs of overheating, using the various online "charts" with pictures of spark plugs as a reference. They all look light gray, but not white, blistered, damaged, or corroded. Granted, I don't drive my car hard (it's a Cruze, not a Camaro), and given my fuelly link, you can hint at my driving habits. I do drive it WOT to redline a few times every tank just to keep the carbon from building up though. 

I would like to make a few comments. My car felt significantly smoother in acceleration at .035" than at .033 or .030, and I quantified this by moving back down this weekend to .030. You can feel more of the engine's vibrations. However, it seems to also have a slight bit more power. I cannot say for certain as the weather has been very unstable lately. 

If you spend some time on this thread and the other thread reading through all of the responses, you'll see numerous complaints that people have posted related to bogging, hesitation, throttle lag, and poor fuel economy at numbers at or under .022, with an increase to .028+ alleviating those problems completely. I ran 93 octane starting on my 3rd tank of gas with this car; the second tank of gas using 89 octane. A few people who increased their gaps tried to go back down to 87 octane, with no success. I personally believe you'll have problems with 87 octane regardless of spark plug gap. 

That said, I agree wholeheartedly that people should periodically check their spark plugs, especially under spirited driving conditions. It takes only 10 minutes.


----------



## titan2782 (Nov 4, 2011)

I read through all of the posts, that's why I went ahead and bumped. I chose 0.028 after reading VT's post. The difference (as I stated previously) was small. It did seem like the engine was louder (more of a purr to it).

However, I could still feel like timing being cut and of course it was running too hot. The car runs just as smooth at 0.022 but without the timing cut. Power wise it still feels like the lame duck it has been.


----------



## XtremeRevolution (Jan 19, 2012)

titan2782 said:


> I read through all of the posts, that's why I went ahead and bumped. I chose 0.028 after reading VT's post. The difference (as I stated previously) was small. It did seem like the engine was louder (more of a purr to it).
> 
> However, I could still feel like timing being cut and of course it was running too hot. The car runs just as smooth at 0.022 but without the timing cut. Power wise it still feels like the lame duck it has been.


What was your original spark plug gap, and how did that run with the tune?


----------



## titan2782 (Nov 4, 2011)

XtremeRevolution said:


> What was your original spark plug gap, and how did that run with the tune?


Stock gap was 0.025 across the board. The plugs were a nice golden brown, but you could still feel timing being pulled. Right around 3000 you could feel it cut out and then it would pick back up around 3800 it would come back in until about 4200. 

I'm pretty surprised at how the car runs now since everyone said they saw noticeable improvements with bigger gaps. I still say there is something funky with my car, but I don't know what and I can't take it in because they'll just send it back with a "no repro" and I'm still at square one.


----------



## XtremeRevolution (Jan 19, 2012)

titan2782 said:


> Stock gap was 0.025 across the board. The plugs were a nice golden brown, but you could still feel timing being pulled. Right around 3000 you could feel it cut out and then it would pick back up around 3800 it would come back in until about 4200.
> 
> I'm pretty surprised at how the car runs now since everyone said they saw noticeable improvements with bigger gaps. I still say there is something funky with my car, but I don't know what and I can't take it in because they'll just send it back with a "no repro" and I'm still at square one.


Pay close attention at *who *says their car runs better. They don't have a tune, and I keep repeating that because it's important. The tune is made for 93 octane, and requires that octane due to both the higher boost levels and the additional spark timing. You are pulling timing because the tune is increasing timing that wasn't on the stock motor. Steve at InsaneSpeed noted that he was seeing spark blowout on as low as .027" with the tune. 

With the stock motor, which was tuned to be able to run on 87 octane, running a .030"-.035" spark plug gap on 93 octane results in virtually no timing retard.


----------



## titan2782 (Nov 4, 2011)

XtremeRevolution said:


> Pay close attention at *who *says their car runs better. They don't have a tune, and I keep repeating that because it's important. The tune is made for 93 octane, and requires that octane due to both the higher boost levels and the additional spark timing. You are pulling timing because the tune is increasing timing that wasn't on the stock motor. Steve at InsaneSpeed noted that he was seeing spark blowout on as low as .027" with the tune.
> 
> With the stock motor, which was tuned to be able to run on 87 octane, running a .030"-.035" spark plug gap on 93 octane results in virtually no timing retard.


I noticed the ones saying it were the ones without tunes. However, I don't normally drive WOT, I normally drive pretty easy maybe getting to 60% throttle. As far as I know ( which probably isn't much) the tune doesn't do anything for the first 2/3 throttle.

It's pulling timing due to knock caused by temps. Again, running at 0.022 seems odd because according to NGK, at higher altitudes, the spark plug tips don't get as hot



> >> Also affects the spark plug's tip temperature
> >> The higher the altitude, the lower cylinder pressure becomes. As the cylinder temperature decreases, so does the plug tip temperature
> >> Many mechanics attempt to "chase" tuning by changing spark plug heat ranges
> >> The real answer is to adjust jetting or air/fuel mixtures in an effort to put more air back into the engine


Based on that last answer, I was wondering if the tune could increase the fuel (making it fat) instead of pulling timing.


----------



## XtremeRevolution (Jan 19, 2012)

titan2782 said:


> I noticed the ones saying it were the ones without tunes. However, I don't normally drive WOT, I normally drive pretty easy maybe getting to 60% throttle. As far as I know ( which probably isn't much) the tune doesn't do anything for the first 2/3 throttle.
> 
> It's pulling timing due to knock caused by temps. Again, running at 0.022 seems odd because according to NGK, at higher altitudes, the spark plug tips don't get as hot
> 
> ...


The tune should still allow the motor to maintain a 14.7:1 AFR during all closed loop conditions. That said, I don't know what the commanded AFR is under WOT. I believe for stock motors it's 13.2:1.


----------



## obermd (Mar 3, 2012)

I run my ECO at 0.035" without a tune. With the MT there is noticable difference in low RPM power vs. 0.025", regardless of octane.


----------



## Ru5ty (Jun 20, 2012)

2012 cruze 2 lt rs 1.4l turbo

2 were at .25 , one .23 one .27

i was blown away

they are all .35 now


----------



## BlueTopaz (Aug 25, 2012)

I just checked my spark plug gaps on our 2012 LT/RS 1.4l and they were all at 0.024 so I bumped them up to 0.032 to see how much of a difference it makes. I found the yellow Lordstown Assembly sheet in the car dated 11/03/11 Time: 01:48:01


----------



## XtremeRevolution (Jan 19, 2012)

Arctic Cat ZRT said:


> Well this weekend I will be home some college, and I am going to be checking the gaps, hopefully if I have time! Now as I was reading through and the GM spec is .35 gap, I also see alot of people going to .30 gap. Which on should I choose? I have the resonator disconnected, and planning to put a K&N filter drop in. I do not have a plan for a tune in the near future.


I tried .030 after some time at .035	to see how it would feel, and I'm not sure I like it. There's notably more engine vibration at .030 and .033 than there is at .035. 

Sent from my myTouch_4G_Slide using AutoGuide.Com Free App


----------



## ShawnB (Feb 17, 2012)

Hey XtremeRevolution,

I checked my plugs today and here are my results.

2012 Cruze 1LT RS 6 Speed Manual
Mods - K&N Typhoon SRI
Also, I always run 93 Octane Fuel
Factory Gap - .022-.023
Re-Gapped Plugs to .035 

I have noticed a much better response in throttle and turbo through 1500-4000RPM Range. I try to keep my shifts to about 3500RPM, but I opened her up a little today with the new gaps and wow.. Before if I was in 4-6th and below 2000RPM the motor just did nothing. Now I can go as low as 1400-1500 RPM and the motor now has life.


----------



## JHC828 (Oct 29, 2012)

Checked mine today. 2012 Cruze LTZ

They were as follows:
#1: .026
#2: .027
#3: .027
#4: .026

I changed them all to .035... Haven't had a chance to drive it yet but I'm hoping I will see a difference after all the posts I've read. Will report back if I find any problems.


----------



## giantsnation (Oct 11, 2012)

I wonder if 2013s got fixed. I just checked mine and they we all at .027/.028 (tough to see the exact gap). But either way they we all the same at factory specs. Mine is 2013 eco mt with 1,588 miles


----------



## bryanakron40 (Nov 8, 2012)

I did the regap on mine yesterday. Mine were all at .027" but I changed it to .032" to see how it does. GM has some of the best ignition systems in the world, so I believe the coils can take the extra gap and not cause any running issues.


----------



## Arcticat (Feb 16, 2012)

I have 2012 ECO A/T, all stock. Plugs where between .024 and .029, used 87 octane. Changed to all .035. Did not notice any big difference. After reading all the posts I determined that a stock 1.4 motor ran best at .028. Changed all to.028 use Shell mid-grade. The car runs great. IN my opinion having your plugs gaped all the same is the most important.--Mike


----------



## jstoner22 (Aug 21, 2012)

0.028 all around. They stayed as is. Upper end of the recommended stock gap is fine for me.

2012 cruze eco MT


----------



## giantsnation (Oct 11, 2012)

I left mine at the .028 spec because I am getting the trifecta tune.


----------



## ShawnB (Feb 17, 2012)

Well after 2 weeks of running at the suggested .035, I was running into issues. The plugs were burning too hot, and fouling out. So, I re-gaped them to .030. Did that 3 days ago, and so far no issues. The car had a lot more Pep at .035, but climbing the mountain to my work was causing the plugs to foul out. No fouling issues yet tho at .030, but lost some of that pep.


----------



## obermd (Mar 3, 2012)

ShawnB, do you have a tune? I ask because I have no problems with 0.035" and I live in Colorado.


----------



## ShawnB (Feb 17, 2012)

obermd said:


> ShawnB, do you have a tune? I ask because I have no problems with 0.035" and I live in Colorado.


No Tune, I only have the K&N Typhoon Short Ram Intake.. Oh and I ALWAYS run 93 Octane from either Shell or Sunoco.


----------



## obermd (Mar 3, 2012)

ShawnB said:


> No Tune, I only have the K&N Typhoon Short Ram Intake.. Oh and I ALWAYS run 93 Octane from either Shell or Sunoco.


OK - which engine? 1.8 (LS) or 1.4T (all others). The 1.8's spec has always been 0.028". The 1.4T spec in the US was originally 0.033-0.037" (GM Maintainence manual) and is now 0.025-0.0275" (GM Powertrain letter to XR).


----------



## ShawnB (Feb 17, 2012)

I have the 1.4T with a 6Spd Manual. Only 6000 miles on her... Running Castrol Edge Titanium Full Synthetic. Not dexos approved, but I love Castrol Edge. My 98Grand Prix ran it for 6 years, with 170,000 Miles, and motor ran like it was brand new LOL


Stock gaps were .023 across all 4 plugs when I took them out a month ago to re-gap them.


----------



## bryanakron40 (Nov 8, 2012)

Shawn, were they actually fouling or were you getting misfires?


----------



## ShawnB (Feb 17, 2012)

They were misfires...


----------



## bryanakron40 (Nov 8, 2012)

OK. Sounds like spark blowout on yours. One reason I stayed at .032". If I get a tune, I may drop the gap if I run into anything.


----------



## XtremeRevolution (Jan 19, 2012)

Just a quick note; I did run my plugs at .038" for a while, and did not get spark blowout until I went up to .040".

Sent from my SGH-T999 using AutoGuide.Com Free App


----------



## bryanakron40 (Nov 8, 2012)

:th_salute: Good info.


----------



## Smdqt (Sep 5, 2012)

Felt the obligation to post in both threads 
Gapped mine last night. I mixed the order, but 2 were gapped at .027 and 2 were at .021. Regapped to ~.035. Can't confirm any improvements so far besides the oddity of a smoother shift from 2nd to 3d (jerking went away)


----------



## jadedgamerx (Nov 12, 2012)

I regapped mine tonight and did the resonator bypass, so far nothing noticeable to report but it was just a quick trip to the gas station to check my air pressure. We'll see how it does on mileage and in traffic before making any judgement calls.

Mine were as follows, assuming Cylinder 1 is closest to passenger seat and Cylinder 4 is closest to driver seat:
Cylinder 1: 0.026
Cylinder 2: 0.026
Cylinder 3: 0.026
Cylinder 4: 0.025

Regapped to 0.035 across all four.


----------



## titan2782 (Nov 4, 2011)

jadedgamerx said:


> I regapped mine tonight and did the resonator bypass, so far nothing noticeable to report but it was just a quick trip to the gas station to check my air pressure. We'll see how it does on mileage and in traffic before making any judgement calls.
> 
> Mine were as follows, assuming Cylinder 1 is closest to passenger seat and Cylinder 4 is closest to driver seat:
> Cylinder 1: 0.026
> ...



Give it about 50 miles before making a judgement call.


----------



## jadedgamerx (Nov 12, 2012)

titan2782 said:


> Give it about 50 miles before making a judgement call.


Something I forgot to remember when I got home, I did notice that the idle was so smooth, I wasn't sure the car was running until I looked at the dash. So that is an improvement, it wasn't bad before, but not "forget the car is running" smooth.


----------



## XtremeRevolution (Jan 19, 2012)

jadedgamerx said:


> Something I forgot to remember when I got home, I did notice that the idle was so smooth, I wasn't sure the car was running until I looked at the dash. So that is an improvement, it wasn't bad before, but not "forget the car is running" smooth.


This is something I also noticed. The engine just runs so much smoother with gaps at .035".

Sent from my SGH-T999 using AutoGuide App


----------



## jadedgamerx (Nov 12, 2012)

XtremeRevolution said:


> This is something I also noticed. The engine just runs so much smoother with gaps at .035".
> 
> Sent from my SGH-T999 using AutoGuide App


I just finished reading all 34+ pages of responses and *holy crap* you have done a lot of work for us XR, thank you! I also learned that I need to let the car re-learn fuel trims (which is something I knew previously with other car modification adventures and completely forgot).

You deserve a beer man, if I'm ever in Chicago I'm looking you up.


----------



## Starks8 (Jul 20, 2011)

jadedgamerx said:


> I regapped mine tonight and did the resonator bypass, so far nothing noticeable to report but it was just a quick trip to the gas station to check my air pressure. We'll see how it does on mileage and in traffic before making any judgement calls.
> 
> Mine were as follows, assuming Cylinder 1 is closest to passenger seat and Cylinder 4 is closest to driver seat:
> Cylinder 1: 0.026
> ...



Some have said it's a must to unhook the car battery before or after performing the spark plug regap so that the car/engine resets itself the new gap readings.


----------



## obermd (Mar 3, 2012)

I didn't disconnect my car battery when I regapped. The car figured it out within a mile or so of driving after I regapped my plugs. The Cruze's ECU has got some really smart software when it comes to how the engine is operating. As a software engineer, I'm impressed at the quality of this car's computer systems.


----------



## jadedgamerx (Nov 12, 2012)

Starks8 said:


> Some have said it's a must to unhook the car battery before or after performing the spark plug regap so that the car/engine resets itself the new gap readings.


I pulled the negative cable and turned the key before I started doing anything, was disconnected and drained for about 30 minutes while I re-gapped and did the resonator bypass. Should have cleared it AFAIK, my window auto-up and date/time were reset.


----------



## speedy862004 (Dec 13, 2012)

My gapper didn't start till .020 and I couldn't get any of the plugs on there without forcing it so mine were all .02 or less.


----------



## XtremeRevolution (Jan 19, 2012)

speedy862004 said:


> My gapper didn't start till .020 and I couldn't get any of the plugs on there without forcing it so mine were all .02 or less.


That's really bad, lol. Not sure if I asked you this, but how much of a difference did you notice?



jadedgamerx said:


> I just finished reading all 34+ pages of responses and *holy crap* you have done a lot of work for us XR, thank you! I also learned that I need to let the car re-learn fuel trims (which is something I knew previously with other car modification adventures and completely forgot).
> 
> You deserve a beer man, if I'm ever in Chicago I'm looking you up.


Haha, thanks man. These 6350+ posts aren't just fluff. 



jadedgamerx said:


> I pulled the negative cable and turned the key before I started doing anything, was disconnected and drained for about 30 minutes while I re-gapped and did the resonator bypass. Should have cleared it AFAIK, my window auto-up and date/time were reset.


I usually just turn the headlights on and that discharges any electricity in the system. Seeing the date/time reset is a good way to know that it was cleared. 

It's not absolutely necessary, but it's a habit I've used on all cars. Whenever I touch the electrical system and change anything, I reset the PCM.


----------



## speedy862004 (Dec 13, 2012)

That's really bad, lol. Not sure if I asked you this, but how much of a difference did you notice?

I certainly noticed it was way more responsive! But as far as normal driving tho, I have noticed making it a smooth 1st to second gear shift is easier and more natural. My k&N drop in will be in today so after work going to drop it in, fill the tank, reset my trip and fuel economy meter and see what the results of the Trifecta Fix (my new name for the 3 musts of this car...Fix plug gaps, bypass resonator, and K&N drop in) will be.


----------



## titan2782 (Nov 4, 2011)

speedy862004 said:


> Trifecta Fix


While your name is valid, I would ask that you choose another word. Trifecta is a vendor and that term could have unintended side effects and cause confusion.

But yeah, those 3 things will give you a noticeable improvement. Let us know how it goes.


----------



## XtremeRevolution (Jan 19, 2012)

speedy862004 said:


> That's really bad, lol. Not sure if I asked you this, but how much of a difference did you notice?
> 
> I certainly noticed it was way more responsive! But as far as normal driving tho, I have noticed making it a smooth 1st to second gear shift is easier and more natural. My k&N drop in will be in today so after work going to drop it in, fill the tank, reset my trip and fuel economy meter and see what the results of the Trifecta Fix (my new name for the 3 musts of this car...Fix plug gaps, bypass resonator, and K&N drop in) will be.


I don't remember exactly what you gapped to, but if you do get a Trifecta tune, keep in mind that you will have to go back down to 0.027"-0.029" to prevent spark blow-out.


----------



## speedy862004 (Dec 13, 2012)

titan2782 said:


> While your name is valid, I would ask that you choose another word. Trifecta is a vendor and that term could have unintended side effects and cause confusion.
> 
> But yeah, those 3 things will give you a noticeable improvement. Let us know how it goes.


I'm aware of the Trifecta tune system. It was kind of a joke...I suppose if we were to come up with a real name for the 3 musts and sticky it on the forum it'd be a good idea (to help out those new to owning a Cruze)

How about the Trigasm of awesome fix.


----------



## speedy862004 (Dec 13, 2012)

XtremeRevolution said:


> I don't remember exactly what you gapped to, but if you do get a Trifecta tune, keep in mind that you will have to go back down to 0.027"-0.029" to prevent spark blow-out.


I don't have Trifecta tune. Not enough money and not sure I'd have the self control to keep my foot out of it for MPG sake after the fix. The trifecta fix was kind of an on the fly nickname for the big 3 to do's with a new Cruze.


----------



## titan2782 (Nov 4, 2011)

speedy862004 said:


> How about the Trigasm of awesome fix.


You sir, have aroused me.


----------



## obermd (Mar 3, 2012)

:signlol:


----------



## DonnieZcruzE (Nov 24, 2012)

Man there's a song in there fo sho!

TRIIIIIGASSSSSSMMMMMMmmmmmmmmmm!


----------



## speedy862004 (Dec 13, 2012)

So after my trigasm of awesome tune.....
I've only gone through 1 tank of gas since and here are the factors and results..

1. There was a morning where traffic had me sitting for over an hour beyond my norm.
2. The temp was consistently colder than when I did my first test of mpg's.
3. I punched the throttle a couple times more than my initial mpg test after switching to 93.

So I went from 33.7(can't remember if manual calculation or just went by gauge.) to drum roll......35.2(that was manual calculation).
So I expect it'll be better than that in the coming months when we get off of winter gas...Awesome!! I plan to inflate tires from 35 to closer to 38 or 40 to get a few more mpg if I can tolerate the more rigid drive.


----------



## titan2782 (Nov 4, 2011)

speedy862004 said:


> So after my trigasm of awesome tune.....
> I've only gone through 1 tank of gas since and here are the factors and results..
> 
> 1. There was a morning where traffic had me sitting for over an hour beyond my norm.
> ...


I'm till on factory tires and I like to keep them at 40psi. I noticed an improvement in MPG and acceleration. Of course, bumps are harder.


----------



## XtremeRevolution (Jan 19, 2012)

speedy862004 said:


> So after my trigasm of awesome tune.....
> I've only gone through 1 tank of gas since and here are the factors and results..
> 
> 1. There was a morning where traffic had me sitting for over an hour beyond my norm.
> ...





titan2782 said:


> I'm till on factory tires and I like to keep them at 40psi. I noticed an improvement in MPG and acceleration. Of course, bumps are harder.


Police officers also run their squad cars at maximum sidewall pressures. This is done for wear reasons and for stability reasons. While having less sidewall "cushion" reduces "ride quality," it does increase stability and predictability in cornering and maneuvers.

After removing the Eco's tires at 50psi and mounting snow tires at 35psi, I found the car almost unsafe during cornering and maneuvering and instantly bumped them to 44psi (max sidewall). They're still quite soft, but I would expect as much from snow tires. I had forgotten how much of a compromise in handling soft tires with lower pressures bring.


----------



## Jmax611 (Jan 6, 2013)

2013 Cruze Lt. .024 .025 .025 .024


----------



## magicstudio (Aug 13, 2012)

2012 LT 1.4T - 0.19 0.24 0.19 0.25 Now i have them all 0.35 (much, much better)

Thanks


----------



## dfwtxpatrick (Apr 22, 2012)

2012 2LT 1.4 Auto - .22 .23 . 24 . 26 and now all are at .35 and my first experience was going from 33mpg to 36mpg on a trip from DFW to Houston.

Also noticed better acceleration and smoother engine idle at all RPMs.

Overall, my weekly avg (to/from work) has risen from 400-420 miles per tank to 440-455 miles per tank.
I had purposely driven the car till the low fuel light comes on so that I am at the same level each time I fill up.

Still consistantly getting 440-455 miles per tank, so I can say with certantity that just adjusting the plug gap can increase mpg!


----------



## silverWS.6 (Jan 6, 2013)

Mine we're ranging from about .018 to .022, changed them to .035 and did notice a smoother idle while warming up and it is a bit "jumpier" during acceleration. My MPG's are still ranging at 30.4 avg but I have gotten up to 33.2 mpg on this tank but I think that's because I have driven a bit more highway this time around so we'll see how that goes. 

Not to mention piece of mind now that is done.


----------



## dsevenem2 (May 29, 2012)

Soooo...

2012 Eco 1.4T 6spd MT - Not tuned.

Is it .029 .030 or .035???


----------



## silverWS.6 (Jan 6, 2013)

dsevenem2 said:


> Soooo...
> 
> 2012 Eco 1.4T 6spd MT - Not tuned.
> 
> Is it .029 .030 or .035???


Went with .035 on mine.


----------



## dsevenem2 (May 29, 2012)

silverWS.6 said:


> Went with .035 on mine.


alrighty i'll give it a shot thanks man


----------



## silverWS.6 (Jan 6, 2013)

silverWS.6 said:


> Mine we're ranging from about .018 to .022, changed them to .035 and did notice a smoother idle while warming up and it is a bit "jumpier" during acceleration. My MPG's are still ranging at 30.4 avg but I have gotten up to 33.2 mpg on this tank but I think that's because I have driven a bit more highway this time around so we'll see how that goes.
> 
> Not to mention piece of mind now that is done.


Just to update this, my Avg. MPG is now at 31.2


----------



## Fool4racing (Jan 29, 2012)

2012 rs ltz .022 .024 .024 .022 moved up to .028 with premium tune much smoother idle. Milage up 1.5 to 2 per gallon


----------



## mastablasta (Feb 26, 2013)

2011 Cruze LTZ 1.4L .020 .023 .023 .025 Went to .035, with a doubt running smoother and much more jumpy acceleration. Only been on the forum 24 hours and I feel like I own a whole different car. Thanks Guys!


----------



## Billdog350 (Feb 27, 2013)

2012 Cruze LT 1.4L RS. .25 .25 .22 .22. Went to .30 across to start with. I'll be very interested to see if there is any noticeable difference. I'm coming from a 2007 Corvette Z51 6.0L so its definitely a little down on power to begin with!

Tires are at 44psi, DIC shows 37mpg but EVERY **** fillup I calculate out to 32-33...I've been logging results on Fuelly too. I'm starting to get fed up with driving all conservatively and only getting 33mpg. I was getting 23 in my Vette driving somewhat aggressively and I tried driving like a 4cyl for a few days and got 26mpg AVG....If I can get 26mpg in a Vette...a 1.4l BETTER be getting me at least 40mpg! I'm only at 2100mi though so maybe a little more break in will help get that number up. I've also gone to Super to see if that helps.


----------



## WhiteAndBright (Mar 4, 2013)

2012 LTZ 1.4L RS. 24,589 miles .019 .020 .020 .018 Changed to .035 and can already feel a difference!! Before the change when I would be sitting at a stoplight it would have a rough idle and almost a slight vibration that I could feel in the brake. I have also changed the air box (bypassing the induct mess) and tires are at 41 psi also have a k&n drop in filter (have been using for almost 2 months). I have a 82 mile roundtrip drive to and from work and have been getting an avg around 25-30 mpg since making the changes that other members on this site have mentioned I have seen an increase to 39 mpg (one trip with a tail wind both ways hit 43 mpg) not to bad if you ask me for my only real "mod" being a drop in filter..


----------



## Starks8 (Jul 20, 2011)

WhiteAndBright said:


> 2012 LTZ 1.4L RS. 24,589 miles .019 .020 .020 .018 Changed to .035 and can already feel a difference!! Before the change when I would be sitting at a stoplight it would have a rough idle and almost a slight vibration that I could feel in the brake. I have also changed the air box (bypassing the induct mess) and tires are at 41 psi also have a k&n drop in filter (have been using for almost 2 months). I have a 82 mile roundtrip drive to and from work and have been getting an avg around 25-30 mpg since making the changes that other members on this site have mentioned I have seen an increase to 39 mpg (one trip with a tail wind both ways hit 43 mpg) not to bad if you ask me for my only real "mod" being a drop in filter..


Nice! Keep us informed of how the car does on the new gapping over the long term. Hey can we get some more pics of your cruze? I also see you are located in Tulsa, you must be sick of the snow and weather at this point huh? You guys getting any snow this week? VA and most of the upper east coast is about to get a big snow storm starting sometime tomorrow and ending sometime Thurs.


----------



## WhiteAndBright (Mar 4, 2013)

Starks8 said:


> Nice! Keep us informed of how the car does on the new gapping over the long term. Hey can we get some more pics of your cruze? I also see you are located in Tulsa, you must be sick of the snow and weather at this point huh? You guys getting any snow this week? VA and most of the upper east coast is about to get a big snow storm starting sometime tomorrow and ending sometime Thurs.


No snow for us this week, it was 76 today!! The weather in Oklahoma is so weird it will be so nice one day and later that night it will start snowing


----------



## Notso4eign (Dec 22, 2012)

Wasn't sure if you guys were still wanting us to keep track. Just got around to checking my plug gaps and from left to right they were .014,.016,.024,.018. '12 Cruze Eco A/T


----------



## Imaperson (Apr 18, 2013)

After some 95+ weather here today, Had a pretty rough idle and hesitant acceleration. Decided to check the plug gaps. 

.019 .020 .022 <.019 ( gap tool didn't have terribly many wires to measure with ) Set them all to .032 on my 2012 1LT RS 1.4T. About 3700mi. Noticed right away that the idle smoothed out to barely able to tell its running.


----------



## Diesel Dan (May 18, 2013)

2013 Cruze, 1LT with 1.4L turbo, auto, 7,100 miles.
Plugs were all at .025-.026", re-gapped to .035".


----------



## CyclonicWrath (May 14, 2013)

2012 Cruze RS, .022 .024 .022. 025 regaped to .028, I fixed rough idle just by switching to 91 fuel but I had extra time so did my plugs as well I herd bad things about gaping them to .035 makes coil pack work a little harder from what I heard but alone with the 91 fuel the car drives totally different no need for a tune, no lag just go!


----------



## Diesel Dan (May 18, 2013)

I'm not so sure I'd worry about working the coils too hard.
While it was a different animal we gapped 3.8L V6 Buicks at .060" on single coil HEI systems.


----------



## xPunKx (Jan 25, 2013)

2012 Cruze lt RS, .022 .019 .023. 022 regaped all to 0.033


----------



## springer64 (May 14, 2013)

2013 cruze eco auto .027 - .028 - .028 - .028. idles and runs perfect, including high rpm - high load. i won't be regapping or messing with the plugs in any way.


----------



## gt_cristian (Apr 7, 2012)

2013 Cruze LT A/T .025 .025 .024 .025. Gapped at .030". Results to follow. Feels like it picks up a little better. I always run 91 octane.

Given I am not tuned and I run 91 octane, should I gap at .035"?


----------



## tecollins1 (Nov 6, 2011)

gt_cristian said:


> 2013 Cruze LT A/T .025 .025 .024 .025. Gapped at .030". Results to follow. Feels like it picks up a little better. I always run 91 octane.
> 
> Given I am not tuned and I run 91 octane, should I gap at .035"?


Most guys could do 0.035 on stock tune.
I actually got spark blow out when above 0.032.
I'd say try it out and if you get blow out set it back to .032 or .030.

You could also get one of my 4ga kits and that will def get you 0.035 
Did this with 2 stock cruzes at the Lordstown meet.


Sent from AutoGuide.com App


----------



## BrianMac (May 15, 2013)

I want to check my own gaps. When reinstalling the plugs, is it ok to go hand tight? Or do I need a torque wrench, I couldn't find the exact info I'm asking on other threads, thanks in advance


----------



## BrianMac (May 15, 2013)

2013 Eco Manual, All were gapped at approx .024, re-gapped to .033. Drove about 10 miles so far, not sure if it is my imagination, but my lag seems to be gone.


----------



## Blue Angel (Feb 18, 2011)

'12 Eco MT. My gaps were initially just over .025". I since bought a set of feeler gauges and a gapping tool. Set them all to .033" and ran fine (stock, no tune), and noticed better low RPM torque and smoothness (below ~1400 RPM). I just set mine to .038" to see how she goes. So far so good, but I haven't gone WOT yet. Will update if anything negative happens.

I also just gapped my buddie's '11 Eco MT. His gaps were all .025"-.026" from the factory. I set his gaps to .033" and we went for a spin. He couldn't believe the difference it made down low. I told him to lug up a hill in 4th gear and he figured his car wouldn't have done it before. I wish we'd have taken it for a spin before the change to see back to back.


----------



## Aussie SRi-V (Aug 25, 2012)

WOW what a long thread.
Re-gapped my 2012 SRi-V 1.4T last night. 
NGK IFR7X7G
Initial 0.024 0.024 0.025 0.023
Final 0.030" across the lot. I'm going to split the difference and see how it goes.
Holden book figure 0.028" CT 0.035"

Torqued plugs to 18 Ft Lb
Ignition Bolts 71 In/Lbs or 8.0Nm

Performance has improved.


----------



## silvercruze1lt (Sep 28, 2012)

2012 1.4 lt
original 0.023 0.025 0.022 0.023
final 0.033 for all
so much smoother than before


----------



## Blancmange (Jan 9, 2013)

2012 1.4 LT
Original .021 .024 .027 .027

Regapped all to .030

No more hesitation! Excellent! Thanks everyone!


----------



## Beth'sRS (Jan 21, 2013)

Well this is officially my first post on the boards! Up until the past week, I hadn't had any issues with my 2011 RS 1.4LT. I noticed yesterday it was falling on its face when taking off from a red light (not every time). It was not pleasant. But, I hopped on here after lunch and decided to have the hubby check my spark plugs when I got home.

He said 2 of the 4 were pretty much touching. The other 2 were .025. He re-gapped them all to .035 and it seemed much better this morning on the way to work. 

Thanks to all of you for putting so much time and effort into this topic. I was freaking out yesterday that my blue bullet was sick! :wink:


----------



## obermd (Mar 3, 2012)

Welcome to CruzeTalk Beth. I'm glad we were able to help.


----------



## Blue Angel (Feb 18, 2011)

Welcome Beth! Glad you found the forum useful!



Beth'sRS said:


> He said 2 of the 4 were pretty much touching. The other 2 were .025. He re-gapped them all to .035 and it seemed much better this morning on the way to work.


.035" is at the upper end of what people are adjusting their gaps to. I would suggest that you check the gaps about once a year to make sure they're not getting any wider, and maybe even consider putting them back down to .030"-.033".

I personally have mine set to .038", but I'm experimenting with another modification in parallel with this and I'm staying on top of it. I gapped my friend's Cruze at .033" to keep him on the safe side and he noticed a big difference.

Enjoy the Cruze, and please browse through the forum every now and then - there's a real wealth of knowledge and experience here for all to see and take part in.


----------



## Roccityroller (Jul 7, 2013)

How big of a difference are people actually noticing. Is it real or that feeling of when you do something and you think you feel improvements, like how all cars feel faster after a fresh wax. 

And are we seeing this still on the '13s/'14s?

I mean the 1.4T feels like I need to rev a bunch to get it off the line, but I chalked that up to it being a turbo car. 

This brilliant insight is brought to you via my Galaxy SIII


----------



## obermd (Mar 3, 2012)

Roccityroller said:


> How big of a difference are people actually noticing. Is it real or that feeling of when you do something and you think you feel improvements, like how all cars feel faster after a fresh wax.
> 
> And are we seeing this still on the '13s/'14s?
> 
> ...


After I adjusted the plugs (0.024" -> 0.030") on jxski07's 2013 ECO MT he discovered he had enough extra torque at 30 MPH in 4th gear to get up the hills near where he lives. Prior to the regapping he had to downshift to 3rd for this same set of hills. I found the same with my 2012 ECO MT with a 30 MPH hill near my house. It definitely improves low end power. 

I suspect drivers with automatics won't notice as much difference since the transmission won't shift up as low as those of us with sticks will shift.


----------



## Beth'sRS (Jan 21, 2013)

Well I took her for a spin during lunch and all seems right with the world.  

I'll get the hubby on *RE-re-gapping* the plugs tonight. If it performs well at .030 (i.e. doesn't feel like it's going to stall when letting off the brake when the light turns green) I'd like to keep it there instead. 
I should have mentioned mine is an automatic, but I'm still noticing a big difference in the low gears and it seems to just run better overall. I'm pleasantly surprised given that it's like 95 degrees today and I had my A/C cranked!

Thanks for the warm welcome! 
-Beth


----------



## Starks8 (Jul 20, 2011)

Using the higher octane gas during the summer months will also help your car run better Beth'sRS.


----------



## obermd (Mar 3, 2012)

Beth'sRS said:


> Well I took her for a spin during lunch and all seems right with the world.
> 
> I'll get the hubby on *RE-re-gapping* the plugs tonight. If it performs well at .030 (i.e. doesn't feel like it's going to stall when letting off the brake when the light turns green) I'd like to keep it there instead.
> I should have mentioned mine is an automatic, but I'm still noticing a big difference in the low gears and it seems to just run better overall. I'm pleasantly surprised given that it's like 95 degrees today and I had my A/C cranked!
> ...


Leave them at 0.035". This was the center point for the original GM Tech manual for the 1.4T engine in the Cruze. My ECO MT is at 0.035". Also, Starks8 is absolutely correct to give mid-grade or premium a try. Search around here for threads on octane to learn why.


----------



## Blue Angel (Feb 18, 2011)

obermd said:


> Leave them at 0.035".


I agree Beth, go easy on the poor hubby!

The car will be fine with the plugs set that way. I just threw the extra advice in there as it never hurts to check your plug gaps periodically. As a "set-it-and-forget-it" recommendation for most people I would reccomend .033", but since you have a "handy hubby" who can keep on top of things, just leave it at .035" and assign him the next item on the "honey-do" list. 

As others mentioned, if you notice the car bogging at all in hot weather with AC use don't "hesitate" to try a tank of premium fuel (pun fully intended). Once the weather cools back down you can easily switch back to cheaper 87.

Enjoy!


----------



## Beth'sRS (Jan 21, 2013)

LOL let's not feel sorry for the hubby. He thoroughly enjoys his alone time in the garage! (We have a 2 year old daughter, need I say more?!)

Thanks for the advice on the octane level. I'm definitely going to try some better gas in ole cruze next time I fill up.

Hmmm, let's see... what's next on the "honey-do" list... OH yeah! Selling 2 of his 3 cars! Sounds good to me. :th_coolio:


----------



## Roccityroller (Jul 7, 2013)

Ok now you're talking crazy people talk

This brilliant insight is brought to you via my Galaxy SIII


----------



## obermd (Mar 3, 2012)

Beth'sRS said:


> LOL let's not feel sorry for the hubby. He thoroughly enjoys his alone time in the garage! (We have a 2 year old daughter, need I say more?!)
> 
> Thanks for the advice on the octane level. I'm definitely going to try some better gas in ole cruze next time I fill up.
> 
> Hmmm, let's see... what's next on the "honey-do" list... OH yeah! Selling 2 of his 3 cars! Sounds good to me. :th_coolio:





Roccityroller said:


> Ok now you're talking crazy people talk
> 
> This brilliant insight is brought to you via my Galaxy SIII


Depends on the cars. If they're Yugos definitely sell them for scrap. 

More seriously, since 0.035" is a good gap for the 1.4T engine, leave it be. Every time you open the engine to do something there is always a small risk of breaking something.


----------



## EcoTech2.0 (May 29, 2013)

Checked my gap on my 13' 1.4 not long ago and they were:
0.027
0.028 
0.028 
0.026


----------



## newsguy99 (May 24, 2013)

my 2012 MT6 Eco was all gapped at .024


----------



## chaser x (Sep 3, 2012)

Ok i brought the tools ill try to gap when i have time so the LS 1.8 2012 has to be gap at .30?


----------



## obermd (Mar 3, 2012)

The spec for the LS has always been 0.028", but since that's not a gap on most tools I would set it to 0.030"


----------



## Roccityroller (Jul 7, 2013)

obermd said:


> The spec for the LS has always been 0.028", but since that's not a gap on most tools I would set it to 0.030"


This is why I always keep a set of feeler gauges with my plug wrench

This brilliant insight is brought to you via my Galaxy SIII


----------



## eedwards (Mar 20, 2013)

I bought my '13 Cruz 1LT this past March.... all 4 plugs were gapped under .025. I regapped them to .034, went to 91 or better gas and love the performance and mpg (around 37). This also took care of the rough idle.


----------



## 99_XC600 (Feb 24, 2013)

Went out this morning and regapped the plugs based on the feedback from the thread. I noticed from the day I took delivery ( 2 days ago) that there seemed some hesitation/stumbling from easy take off's, almost like it didn't know what to do.

The factory gaps were. 25 , 26 , 25, 27.

I went ahead and regapped then to .033 and went for a quick 15 mile ride. Stumble/Hesitation is just about gone. I attribute the remainder to the 87 Octane the dealer had filled it up with. I also noticed that going up some medium size hills that it stayed in 6th gear and didn't down shift.

Thanks to everyone who has posted not only in this thread but everything else. I've learned a lot and it's been an excellent resource.


----------



## vap3riley (Jul 28, 2013)

2013 LS 1.8, from factory the plugs were 26, 27, 25, 25. Raised to 35 each and definitely notice a difference in lag and performance.


----------



## aharnak (Feb 25, 2013)

In my 2014 2LT Manual (1.4 T), the gaps were .27, .27, .25, .26. I gapped all of them to .25 as per the manual, although it seems like most people are gapping them much wider.


----------



## obermd (Mar 3, 2012)

aharnak said:


> In my 2014 2LT Manual (1.4 T), the gaps were .27, .27, .25, .26. I gapped all of them to .25 as per the manual, although it seems like most people are gapping them much wider.


Wow - GM has really brought the "official" gap down. The first service manual was 0.033-0.037" for the 1.4T in the Cruze. The owners manual said 0.028". It must have been cheaper to reprint the manual to match what NGK was told to deliver.


----------



## aharnak (Feb 25, 2013)

obermd said:


> Wow - GM has really brought the "official" gap down. The first service manual was 0.033-0.037" for the 1.4T in the Cruze. The owners manual said 0.028". It must have been cheaper to reprint the manual to match what NGK was told to deliver.


I don't have my manual on me at the moment, but if I remember correctly it said .24 - .28 for the 1.4L


----------



## Boostpatrol (Jul 30, 2013)

2012 2LT RS and gap was 0.025"
And my Canadian manual says gap should be 0.028" which is what I set them too now. 

Sent from AutoGuide.com Free App


----------



## SnowBlindLTZ (Jan 4, 2012)

This is BS. I have had my cruze for almost 2 years and have always complained that the car felt sluggish. I leased another cruze this spring for my wife and hers feels like it has 40 more hp, until i re-gapped the plus in mine yesterday....now my car feels like it has more hp than hers. Mine were set at 25, 23, 23, 24 and i reset them all to 35. I am very disappointed this is happening and that GM is so careless.


----------



## NYCruizer (Jul 10, 2013)

2012 1LT/RS .025, .026, .025, .025 => opened the gap to .032 and she's got more pep and torque and no more hesitation.


----------



## OutOThsWrld (May 26, 2013)

2013 LS. Gaps were .025 across the board.


----------



## HeresJonny (Jun 25, 2013)

Not sure if anyone is still putting these statistics to use, but I'll happily add mine...

2011 1LT:
0.027
0.027
0.025
0.027

I didn't have anything between my .025 and .028 wires, so the .027 is estimated. I gapped the .025 up to match the rest.


----------



## BigMoe (Aug 19, 2013)

2013 LS all 4 were just under 0.025. Smallest wire any of the gap tools had around here 

Sent from AutoGuide.com App


----------



## CanaryGT (Aug 12, 2013)

Just finished doing this myself. 

Plug 1 - 0.020
Plug 2 - 0.024
Plug 3 - 0.022
Plug 4 - 0.020

I was WAY off. Hoping this will solve that sluggish feeling.


----------



## newsguy99 (May 24, 2013)

CanaryGT said:


> Just finished doing this myself.
> 
> Plug 1 - 0.020
> Plug 2 - 0.024
> ...


Wow!! You're going to think you bought a new car, or put a different engine in it, after you re-gapped..


----------



## CanaryGT (Aug 12, 2013)

newsguy99 said:


> Wow!! You're going to think you bought a new car, or put a different engine in it, after you re-gapped..


Yeah I drove it last night and today. The car is literally completely different. I didnt know how much is was going to change... It no longer is sluggish down low. I can still feel the slight turbo lag but its not like a HUGE push anymore like it used to be.


----------



## modalita (May 25, 2013)

I did my wife's 2012 1.8 Sonic, and my 2012 1.4 Eco Cruze yesterday. Her sonic was .25 all around, and my Cruze was about .21 all around. On the 1.8, we got a huge boost on fuel economy, and on the 1.4T it was more responsiveness.


----------



## airbornedave (Jan 26, 2013)

I will be changing the gap on my plugs when my Cruze gets back from the shop getting warranty work done. With that said, I can't verify anything right now, but can anyone tell me if this is the procedure to get to the spark plugs on the 1.4L turbo?






If so, this is the easiest access to spark plugs that I have ever had in a vehicle!


----------



## corvairbob (Dec 17, 2012)

XtremeRevolution said:


> If you changed your spark plug gap per this thread or this thread, please report what the original values were here. If you have yet to change them, please remember to report the original values.
> 
> My case with GM has been escalated to a district case manager at GM to hopefully get some exposure on this issue. My primary goal is to allow people to go to their dealerships and have their spark plug gaps checked and corrected (as there has been a 100% error rate so far), and the more people and numbers I can present them with, the better.
> 
> ...


my 13 ltz/rs had from left to right .020 .022 .022 .023 
i move it to all .032 now is this a good number? i had them all at .030 for a while but change last weekend. what other plug do these cars like. i see some don't care for the stock plug. and i see they can break easy so a different plug may be easier to deal with. this last time i took them out they were sooty? never had that much soot on plugs before what makes that so bad on these cars? can anyone tell me if the trifecta tune would do me any good for a 7 mile one way to work trip? bp.


----------



## XtremeRevolution (Jan 19, 2012)

corvairbob said:


> my 13 ltz/rs had from left to right .020 .022 .022 .023
> i move it to all .032 now is this a good number? i had them all at .030 for a while but change last weekend. what other plug do these cars like. i see some don't care for the stock plug. and i see they can break easy so a different plug may be easier to deal with. this last time i took them out they were sooty? never had that much soot on plugs before what makes that so bad on these cars? can anyone tell me if the trifecta tune would do me any good for a 7 mile one way to work trip? bp.


.035" is what I recommend for stock motors. 

Replace with stock plugs. They are good quality and work well. If you don't like them as much, you csn go with a copper plug but be advised that they will need to be replaced far more often. 

The Trifrcta tune won't improve fuel economy by any consequential amount unless you have an automatic transmission, and even then it won't be a huge difference. 

Not sure what you mean by soot. Can you take a picture? What kind of fuel do you use?

Sent from AutoGuide.com App


----------



## airbornedave (Jan 26, 2013)

XtremeRevolution said:


> .035" is what I recommend for stock motors.


I just regapped my plugs to .035 in less than 15 minutes from hood open to close. 

In order from left to right, they were factory gapped at 24, 25, 26, 25. 

2012 ECO, 1.4L turbo, A/T

On a side note, I can't believe how easy they were to access! Even my dad's old 440 Cuda takes longer to change plugs in, and there's a ton of room in that engine well.


----------



## SunnyinHollister (Mar 17, 2011)

Just did my 2013 Eco MT:

#1 - 0.027
#2 - 0.026
#3 - 0.026
#4 - 0.026


----------



## steve333 (Oct 23, 2010)

Seems to be an ongoing issue. Did GM ever say anything about it? Wonder if it's happening with the Sonic as well?


----------



## steve333 (Oct 23, 2010)

What really seems odd is that all the plugs weren't gapped the same amount, wouldn't this affect how the engine idles and runs?
Not a tech guy so I'm not sure, but it seems like they should all be the same


----------



## obermd (Mar 3, 2012)

steve333 said:


> What really seems odd is that all the plugs weren't gapped the same amount, wouldn't this affect how the engine idles and runs?
> Not a tech guy so I'm not sure, but it seems like they should all be the same


Inconsistently gapped plugs give the ECU fits. It assumes the same amount of spark and time to spark on each cylinder - the code to do otherwise would be far more complex and this code is already complex enough. My gut feel is that just getting the plugs gapped consistently is at least half the drivability improvement being reported.


----------



## steve333 (Oct 23, 2010)

Surprising (or maybe not) that GM hasn't given Lordstown this info to get them to check the gaps


----------



## newsguy99 (May 24, 2013)

Has anyone else noticed any ticking type noise coming from the engine after re-gapping the plugs? It only happens to me when the engine has been running awhile, and is up to temp..
Doesn't seem to effect anything, just kinda strange hearing that noise..


----------



## airbornedave (Jan 26, 2013)

newsguy99 said:


> Has anyone else noticed any ticking type noise coming from the engine after re-gapping the plugs? It only happens to me when the engine has been running awhile, and is up to temp..
> Doesn't seem to effect anything, just kinda strange hearing that noise..


If it happened immediately after gapping them, I would check to make sure that all of the plug boots sat on there straight. Sometimes one will get crooked when you replace the coils


----------



## obermd (Mar 3, 2012)

Penguin LS: 3 at 0.024 and 1 at 0.027. All four now at 0.030.


----------



## 2013LT (Jul 3, 2013)

I only got one pulled out and it was .022


----------



## airbornedave (Jan 26, 2013)

2013LT said:


> I only got one pulled out and it was .022


Why only one? The electrode "issue"?


----------



## 2013LT (Jul 3, 2013)

Yea I'm not pulling any out until I retrieve my proper gapper (wire type) and can do it properly before I bend another electrode. lol. Bad thing is I have to wait for a spark plug for a few days but it's safe to drive the way it is.


----------



## airbornedave (Jan 26, 2013)

I don't blame you. I love my wire gap guage with the nice tab to bend the anode, but I still use the solid disc guage to measure the final gap with.


----------



## 2013LT (Jul 3, 2013)

Yes... I use mine for that too...  Actually my wire gauge starts at the higher end at .040 ( I think ). Well over the cruzes specs anyway so I have to use the disc.


----------



## jandree22 (Sep 19, 2011)

2014 Cruze Eco 6MT

Passenger |0.025--0.025--0.025--0.025| Driver

My gap tool only goes down to 0.025 but the wire passed _just_ through on all plugs, pretty consistent. All now gapped to 0.035" and the engine is smoother with more linear power delivery from 1-2k rpm. 6th gear now pulls nicer at ~ 38mph and can be used more often (ie, slower) now. Nothing earth shattering but glad I did it nonetheless, thanks to all who contributed info/advise on this fix.


----------



## XtremeRevolution (Jan 19, 2012)

I went through and updated the list for the last time. I think this is about as good as this list is going to look moving forward. The consistency is downright horrible. It shouldn't be this difficult to make spark plugs, but I won't get into this right now. Everyone should continue to check their spark plugs, especially for 2011 and 2012 Cruzes. 

We have recorded a total of 170 Cruzes, 680 spark plugs, recording as low as 0.014 and as high as 0.030.


----------



## Blue Angel (Feb 18, 2011)

Any way to get that pic a little larger?


----------



## XtremeRevolution (Jan 19, 2012)

Blue Angel said:


> Any way to get that pic a little larger?


Right click the image and select the "view image" option, or using the following link:

http://imageshack.com/a/img850/5848/b0px.jpg


----------



## steve333 (Oct 23, 2010)

Has this been reported to GM?


----------



## XtremeRevolution (Jan 19, 2012)

steve333 said:


> Has this been reported to GM?


Long time ago. There are a couple of other threads on this topic. They improved consistency significantly in vehicles produced in the second half of 2012.


----------



## Blue Angel (Feb 18, 2011)

XtremeRevolution said:


> Right click the image and select the "view image" option...


I'm using Chrome, no such option. But if I right click and select "Open in new tab" it shows up full size. Thx


----------



## rcclockman (Jan 16, 2012)

July 2012 Ltz...All Plugs at .028 using a real feeler gauge....How do you know that the gap tools you guys are using are correct? You think those .99ct ones next to the register at pep boys are right? ya right...


----------



## Blue Angel (Feb 18, 2011)

rcclockman said:


> July 2012 Ltz...All Plugs at .028 using a real feeler gauge....How do you know that the gap tools you guys are using are correct? You think those .99ct ones next to the register at pep boys are right? ya right...


My $4 Lisle gapper is accurate to within 0.001", verified with a set of real feeler gauges. My copy reads 0.001" higher than the actual gap:

Lisle 67870 Spark Plug Gauge Gap : Amazon.com : Automotive

I think it's pretty safe to assume that any brand name gauge is going to get you in the ballpark, and even using a cheap gauge is better than just tossing them in the way they came without checking them. Also, it's not critical to get your plug gaps _perfect_, they just need to be close. Within a couple thou of the target is good enough.


----------



## Hmnrcn (Jan 13, 2014)

Mine were 0.024 all the way across. Re-gapped to 0.031 today and will see how it goes.


----------



## jandree22 (Sep 19, 2011)

rcclockman said:


> July 2012 Ltz...All Plugs at .028 using a real feeler gauge....How do you know that the gap tools you guys are using are correct? You think those .99ct ones next to the register at pep boys are right? ya right...


Manufacturing a consistently accurate gauge for a wire gapper tool isn't exactly rocket science.


----------



## [email protected] (Aug 3, 2013)

2013 1.4L LT2, .023, .024, .024, .024.
Re gapped to .34

Drove 200 miles round trip today - MPG 35.4
MPG on same drive was previously 30.8

It is like a new car. The wife drove it and said it felt lighter - her way of saying it is no longer bogging down at low rpm.


----------



## pL2014 (Dec 29, 2013)

I just checked and re-gapped my 2014 LTZ. They were from left to right standing at the front of the car .024 .025 .024 .023. I put them all to .031. I also shoved a paper towel between the firewall and the bracket which holds 2 brake lines and 2 fuel lines to try and stop what sounds like an exhaust leak. 

I drove a couple miles around town. Reminds me of the other Cruze I test drove. Mine has never been quite right since I've gotten it home but I couldn't put my finger on what it was. It was like a completely different car. I pulled the paper towel out when I got home, but I haven't driven it again yet. I don't know yet how much was the re-gapped plugs and how much was the paper towel, but I'm really happy either way.... If it was the paper towel, at least I've found the problem and can figure out a more permanent solution.


----------



## obermd (Mar 3, 2012)

If it's the paper towel you can take it in and have it fixed. If it was the spark plugs you've already fixed it. Either way you have a win.


----------



## pL2014 (Dec 29, 2013)

Just got back from picking up some pizzas. It ran great without the paper towel. I either bent the lines just enough that they don't rub anymore, or it was the spark plugs. Not exactly a properly executed scientific experiment, but I'm happy anyway.


----------



## SportBilly (Nov 25, 2013)

2011 1.4T auto ltz they were .20


----------



## tlucas (Jan 11, 2014)

2014 Cruze LT 1.4 automatic. All plugs measured .024" with a feeler gauge. Changed them to .035"


----------



## SkidooSteve12 (Jul 5, 2012)

2012 ECO 6M 1.4T from left to right standing in front of the car: .025", .026", .025", .026" and regapped to .035" with stock plugs. I have a set of NGK copper plugs waiting to go in, but was curious how the regapped stock plugs would feel. Definitely woke up the car and runs better, has more power to hold a taller gear than before. I don't know why I kept putting off doing some work on the car, has 36,000 miles on it now. It is at the dealer again to get the odors fixed and just had the steering fixed too. I know I was getting much better MPG on the partial tank before dropping it off at the dealer again, so really curious to run a full tank of 87 octane gas on my normal work commute. My guess is it will go up 3-4 MPG easy as others have noted.


----------



## steve333 (Oct 23, 2010)

You're better off running Premium


----------



## Sanjay Collins (Jun 25, 2013)

I was lucky enough to have .027, .027, .028 and .028 on the factory plugs.


----------



## Diesel Dan (May 18, 2013)

steve333 said:


> You're better off running Premium


Our car has seen no measurable gain in fuel economy running 93 octane over 87.


----------



## Blue Angel (Feb 18, 2011)

Diesel Dan said:


> Our car has seen no measurable gain in fuel economy running 93 octane over 87.


It's definitely a case by case basis. Those who drive at high speeds and/or drive more aggressively around town are more likely to see a mileage improvement with higher octane fuel. I don't see an increase in mileage with 91 vs 87, but I'm a very easy driver.


----------



## Vetterin (Mar 27, 2011)

rcclockman said:


> July 2012 Ltz...All Plugs at .028 using a real feeler gauge....How do you know that the gap tools you guys are using are correct? You think those .99ct ones next to the register at pep boys are right? ya right...


I eyeball mine. :dazed052:


----------



## obermd (Mar 3, 2012)

Vetterin said:


> I eyeball mine. :dazed052:


So did whoever was checking them at NGK.


----------



## jandree22 (Sep 19, 2011)

Watching Mary Barra's testimony to Congress yesterday, it's no wonder we have a problem like this. IIRC, specification on the ignition spring torque was 20 +/-5. When asked why the range of 4-10 was deemed "acceptable", she basically said it's not GM's practice to always follow [our own] specs... going onto explain how it's analogous to GM buying out-of-spec steel for frames. What a mess. All I know is I'll _never _question any thread on this site claiming a better (ie, correct) spec setting on something. /rant


----------



## XtremeRevolution (Jan 19, 2012)

Those little half dollar gauges at the auto store are actually fairly accurate. I checked one with a digital caliper once. 

Still not suitable for use on iridium plugs.

Sent from AutoGuide.com App


----------



## Blue Angel (Feb 18, 2011)

jandree22 said:


> All I know is I'll _never _question any thread on this site claiming a better (ie, correct) spec setting on something. /rant


Well, I'm a firm believer in the strength and abilities of the Engineering teams at the OEM level. In most cases, when you dig deep enough you'll see that there are very good reasons for doing things a certain way. It very well could be that the spark plug gap spec was tightened for some reason that goes un-detected by us, like something emissions related for example, and that opening the gap enhances performance in an area we CAN detect while compromising performance in some way we cannot.

Having said that, the commedy of errors that comes from mixing Accounting and Purchasing practices along with sporatic issues with Supplier Quality can toss a wrench into even the most thoroughly Engineered systems. I can guarantee you this, being an Engineer at a company like GM (or any other large auto manufacturer) can be an infuriatingly frustrating thing at times as there is always a battle between doing things right and saving money.

As an Engineer responsible for a part or system, I would want to develop it in the most robust way possible. Fighting me every step of the way will be the Accountants and Purchasing, who lean heavily on Past/Best Practices as a financial guideline. Making something better is an uphill battle where every tenth of a penny counts, especially on a mass produced car like the Cruze. For example, on a car with an annual production rate of 250,000 units/year, saving the company fifty cents per vehicle just paid for an Engineer's complete salary/benefits.


----------



## jandree22 (Sep 19, 2011)

Agreed, the problem is in large part attributed to the actuarial types which I suppose are a necessary evil to any financially sound business. Unfortunately, their formulas don't always get it right.

I have no doubt that GM employs some of the brightest engineers on the planet. They gave us the three V's... Vette, V-Series and Volt.


----------



## arodenhiser (Dec 13, 2013)

2011 1.4T LT1 6A with 65000km or 40000 miles. From left to right standing in front of the car looking at the engine .023", .026", .021", .027"

I am the 2nd owner, and believe these are the original. I changed the plugs to NGK BKR7E-4644, copper cored plugs gapped at .033". I bypassed the intake resonator at the same time. Both changes resulted in noticeable smoother idle, smother rpm climb, and acceleration. The Cruze feels like a new animal. It seems to pull/haul really well from 22-3500 rmp. Fuel economy is going up but I did the changes in the middle of the coldest portion of winter so that kills any mpg claims. Very pleased with these simple changes for my daily driver Cruze.

Adam


----------



## steve333 (Oct 23, 2010)

Diesel Dan said:


> Our car has seen no measurable gain in fuel economy running 93 octane over 87.


It should help with power though


----------



## obermd (Mar 3, 2012)

XtremeRevolution said:


> Those little half dollar gauges at the auto store are actually fairly accurate. I checked one with a digital caliper once.
> 
> Still not suitable for use on iridium plugs.
> 
> Sent from AutoGuide.com App


The work just fine. You simply can't touch the tip. I use the slot to directly bend the ground strap.


----------



## obermd (Mar 3, 2012)

jandree22 said:


> Watching Mary Barra's testimony to Congress yesterday, it's no wonder we have a problem like this. IIRC, specification on the ignition spring torque was 20 +/-5. When asked why the range of 4-10 was deemed "acceptable", she basically said it's not GM's practice to always follow [our own] specs... going onto explain how it's analogous to GM buying out-of-spec steel for frames. What a mess. All I know is I'll _never _question any thread on this site claiming a better (ie, correct) spec setting on something. /rant





Blue Angel said:


> Well, I'm a firm believer in the strength and abilities of the Engineering teams at the OEM level. In most cases, when you dig deep enough you'll see that there are very good reasons for doing things a certain way. It very well could be that the spark plug gap spec was tightened for some reason that goes un-detected by us, like something emissions related for example, and that opening the gap enhances performance in an area we CAN detect while compromising performance in some way we cannot.
> 
> Having said that, the commedy of errors that comes from mixing Accounting and Purchasing practices along with sporatic issues with Supplier Quality can toss a wrench into even the most thoroughly Engineered systems. I can guarantee you this, being an Engineer at a company like GM (or any other large auto manufacturer) can be an infuriatingly frustrating thing at times as there is always a battle between doing things right and saving money.
> 
> As an Engineer responsible for a part or system, I would want to develop it in the most robust way possible. Fighting me every step of the way will be the Accountants and Purchasing, who lean heavily on Past/Best Practices as a financial guideline. Making something better is an uphill battle where every tenth of a penny counts, especially on a mass produced car like the Cruze. For example, on a car with an annual production rate of 250,000 units/year, saving the company fifty cents per vehicle just paid for an Engineer's complete salary/benefits.


These two posts explain why the response GM gave about the spark plug gap was so infuriating. Nowhere in the response was the engineering reasons for the response. Instead it was a very paternalistic mother ship GM knows best type of response. If they had come back and stated what I measured this past January we would have all jumped on board and said 0.028" it is.


----------



## obermd (Mar 3, 2012)

arodenhiser said:


> 2011 1.4T LT1 6A with 65000km or 40000 miles. From left to right standing in front of the car looking at the engine .023", .026", .021", .027"
> 
> I am the 2nd owner, and believe these are the original. I changed the plugs to NGK BKR7E-4644, copper cored plugs gapped at .033". I bypassed the intake resonator at the same time. Both changes resulted in noticeable smoother idle, smother rpm climb, and acceleration. The Cruze feels like a new animal. It seems to pull/haul really well from 22-3500 rmp. Fuel economy is going up but I did the changes in the middle of the coldest portion of winter so that kills any mpg claims. Very pleased with these simple changes for my daily driver Cruze.
> 
> Adam


This leads me to believe this car had two plugs less than 0.020" when new. I wonder what the previous owner thought of the performance.


----------



## dhpnet (Mar 2, 2014)

Checked mine today. My 2014 1LT has 2K miles on it. Gaps were .024, .024, .025, .026. I re-gapped them all to .028. I was amazed at how beautifully polished the spark plug holes look. The plugs almost looked new, but there was already a very light amount of carbon forming on the base of the plugs. 

Also added dielectric grease on the battery terminals while I was in there.


----------



## Merc6 (Jun 8, 2013)

Diesel Dan said:


> Our car has seen no measurable gain in fuel economy running 93 octane over 87.


My car will get you killed on 87. Even with the V power plugs and a/c off 1st gear bog is there in full force. If I came to a stop sign I either ran it or blip throttle and California rolled it. If you left t/c on and traction control killed power on 87 it would misfire and stall easier. 

2013 ECO 6m v power copper gapped .030 checked a few days ago. 

Sent from my iFail 5s


----------



## dhpnet (Mar 2, 2014)

dhpnet said:


> Checked mine today. My 2014 1LT has 2K miles on it. Gaps were .024, .024, .025, .026. I re-gapped them all to .028. I was amazed at how beautifully polished the spark plug holes look. The plugs almost looked new, but there was already a very light amount of carbon forming on the base of the plugs.
> 
> Also added dielectric grease on the battery terminals while I was in there.


I ran the car at .028 for about 5 days and there seemed to be less torque at takeoff and less power passing cars on a hill on the freeway. It didn't push me back into the seat like it used to. My 1LT is auto, but I often use the sport shift mode. I regapped them back to .025 and it actually seemed to improve. It's strange because I thought .028 was GM's spec. I am thinking about trying some other gaps just to see the difference. I love how this car pushes me back into the seat when I take off. It even surprised some friends.


----------



## Blue Angel (Feb 18, 2011)

dhpnet said:


> I ran the car at .028 for about 5 days and there seemed to be less torque at takeoff and less power passing cars on a hill on the freeway. It didn't push me back into the seat like it used to.


Interesting. People generally report better performance with larger gaps, right up until the gap is wide enough to allow spark blowout at higher RPM, and that doesn't seem to be happening with gaps less than .035" on the stock tune and .028" on tuned cars.

For $10 you should try the 4644's and experiment with the gaps on those. If your results continue to be different than everyone else's there may be some other factor in play.


----------



## dhpnet (Mar 2, 2014)

I think I will try .03 and see what happens. I wonder if these cars don't like platinum and iridium. My old Saturn hated platinum plugs, and everyone on the Saturn forum reported the same.


----------



## alexeilb (Feb 26, 2011)

2011 LS Auto @ .030 all around, replaced them with Autolite iridium gaped @ .035 noticed better peddle response, RPM use to drop quite a bit before shifting now it shifts smooth without the drop off, I feel much more confident to overtake as there is no more hesitation.


----------



## obermd (Mar 3, 2012)

dhpnet said:


> I think I will try .03 and see what happens. I wonder if these cars don't like platinum and iridium. My old Saturn hated platinum plugs, and everyone on the Saturn forum reported the same.


They don't like platinum. The OEM plugs are iridium and once properly gapped work reasonably well. There are better plugs for the car but they don't last as long, which is what eliminated them from consideration for OEM use.


----------



## Merc6 (Jun 8, 2013)

I'm about a week from installing my 7EIX's which is the iridium version of the popular v power coppers. I'm on OEM plugs now so I can fully feel and appreciate the difference when I do swap em.


----------



## obermd (Mar 3, 2012)

.028" is the correct gap for all gen 1 gas Cruzes.


----------



## Merc6 (Jun 8, 2013)

Merc6 said:


> I'm about a week from installing my 7EIX's which is the iridium version of the popular v power coppers. I'm on OEM plugs now so I can fully feel and appreciate the difference when I do swap em.


Since it got bumped, I later swapped to the 8EIX with a new coil pack and still happy with the choice and said gap above. Low rpms in 6th gear no tune, handles just fine. Talking a level road cruising state not a low rpm wot state from car in front slowing down to turn. I'd simply go to 5th and be well enough off to speed back up to traffic flow again.


----------



## RedEco (Jul 25, 2016)

.035 the way to go on a 14 1.4T?


----------



## jblackburn (Apr 14, 2012)

RedEco said:


> .035 the way to go on a 14 1.4T?


No. .028"


----------



## dbcoop (Sep 2, 2017)

changed my plugs today.. car has 119k miles.. plugs are stock.. two of them were .27-28, and two were .25-.26


----------



## RussT (Sep 8, 2017)

2011 Cruze Eco gaps of .29, .30, and 2 at .31. I am not sure if these are original or not. I bought the car with about 94,000 and it now has 103,000. Hope this helps. 
Thanks again for the parts and help with my vacuum/pcv problem.


----------



## 12ecofamilycar (Jul 7, 2019)

While doing other engine work I checked the plugs in my 2012 eco.
All gaps were 29, my owners manual specifies 28. I think they are 2012 factory originals as I bought at 30000 miles from dealer. What brand would GM factory have installed? NKG? All in nice condition as were springs etc. Except #2 was not tightly secured and that well had a light tan coating on the well wall. I'll post a photo if color difference is visible.


----------



## Blasirl (Mar 31, 2015)

From *Hesitation...GONE!*

*-BKR8EIX-2668* (iridium plugs), ~$25, expect ~10-15k regaps on these, ~40-50k overall life.
*-BKR7E-4644* (nickel/copper plugs), ~$8, expect 15-25K out of these plugs, with a regap or two required at 5-8k intervals on stock tune.


----------



## snowwy66 (Nov 5, 2017)

Wonder why they don't list that on the underhood label anymore.


----------



## Mack (Nov 8, 2016)

snowwy66 said:


> Wonder why they don't list that on the underhood label anymore.


It's probably because the amount of drivers working on their own cars is dwindling. And any info they put there can be googled pretty easily. We wrench-turners are a dying breed.


----------



## snowwy66 (Nov 5, 2017)

Problem with google is mixed results though. 

One guy on here asked about his rear wheel alignment and I got 4 different specs from google. 

Same problem when I research motorcycles I'm considering. None of them have the same horsepower ratings for any given bike. Have to find a service manual and even those are tough to find mostly.


----------

