# Dumped the NGK IFR7X Spark plugs that came in my 2012 1.4L Turbo



## Patman (May 7, 2011)

The super thin center electrode design is the "Iridium plug design" Surpised the whatever out of me when I replaced in my 2003 Alero and my wife's 2005 Malibu. Don't know if I like it? Maybe I will change for platinum. Any ideas about the Iridium plug?


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## XtremeRevolution (Jan 19, 2012)

The big question now is, did you notice all of this difference because of the new plugs, or because of the adjustment in spark plug gap? What were your original plugs gapped to?

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## NickD (Dec 10, 2011)

NGK's were gapped at 0.071 mm or 0.028", translated, same precise gap. They came from the factory that way, just checked them.

I tried those Bosch thin electrode in my 88 Supra, those are a job to change, very dissappointed with the performance, got rid of them.

Iridium is not a natural earth element, only found in meteorites from outer space, so should assume since more expensive and from outer space, should be better, right? I put those in my Cavalier with not very good results.

NGK's were okay cruising down the highway with light engine loads, really noticed a big difference when accelerating, where the turbo kicks in. No misfire codes, really can't check that when accelerating, drops back to open loop mode with a constantly changing rpm. Taking a 450 mile trip this coming weekend, see how it does.

Ha, who misspelled dumped? Shame on me.


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## XtremeRevolution (Jan 19, 2012)

Really...out of 79 vehicles we've had reported, only one of those had plugs that were .028. That's a pretty small percentage, unless you had a dealership check and re-gap them for you. 

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## NickD (Dec 10, 2011)

70AARCUDA said:


> ...some "enlightenment" reading about the NGK plugs installed in 1.4LT engines: http://www.ngk.de/fileadmin/templates/Dokumente/EN/Presse/2010/20100914_V2_NGK_Presseinfo_EN.pdf
> 
> ...and, here's info about the different electrode materials (table midway down): High Performance BRISK Silver Spark Plugs for Vauxhall Opel Petrol, LPG & CNG Motor Vehicles


Wow, after reading about how great the NGK's are, I should go back to them. Japanese did hire a bunch of American engineers in the late 70's and early 80's, I was one of them to show them how to design a decent alternator and ignition system. But that was short term, just long enough to pick our brains, apparently they forgot what we taught them. 

Autolites are designed in the USA, but unfortunately Made in Mexico, can blame our EPA for that.

Also felt the carbon buildup on the tip of the white center electrode was excessive on these NGK's with only 5,000 miles on the plug. Either too cold of a plug, but definitely a sign of misfiring. Use to be able to buy plugs with different heat ranges, that has also become history.

Couldn't even find the plug I was looking for in town so ordered them from rockauto.com, are $3.59 each and S&H charges were literally a couple of bucks.


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## StoneCrab (Sep 14, 2011)

I swapped to the Autolite APP3923 today, based in part on NickD's experience. I gapped them to .030. Factory plugs were at .025, .022, .025, .022 - very small seems to me. I have always experienced the slight hesitation and pulsing during acceleration that seems to be a common trait in the 1.4s. I run 93 octane partially because that hesitation seems to be much less on higher octane. I was hoping the new plugs might solve that problem entirely. The first drive with the new plugs I got the engine up to temp and tried some full throttle acceleration in gears 2 through 4. I felt 5 or 6 clear misfires and stumbles, much worse than the slight pulsing normally felt (these were obvious misses and I'm surprised I didn't get a CEL), and I thought s*** that didn't work. I wondered if maybe the .030 gap was too big and that maybe there is a reason the factory plugs are gapped so small. I continued to drive though and subsequent acceleration runs felt very smooth, with no misfires and also no hesitation or pulsing! Seems very smooth now, even at low RPM and WOT. Too early to tell if any change in MPG. As long as I don't experience any more misfires, and there is no drop in MPG, I'll keep these plugs and be happy that the hesitation has gone away. Otherwise I'll put the stock plugs back in. But why would it miss those few times, then run fine? What adjustment would the ECM do regarding new plugs? Think the gap is still too big?


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## mcg75 (Mar 5, 2012)

Interesting. Both the info on our jobber site and the NGK site list the gap for the Cruze at .027"


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## NickD (Dec 10, 2011)

StoneCrab said:


> I swapped to the Autolite APP3923 today, based in part on NickD's experience. I gapped them to .030. Factory plugs were at .025, .022, .025, .022 - very small seems to me. I have always experienced the slight hesitation and pulsing during acceleration that seems to be a common trait in the 1.4s. I run 93 octane partially because that hesitation seems to be much less on higher octane. I was hoping the new plugs might solve that problem entirely. The first drive with the new plugs I got the engine up to temp and tried some full throttle acceleration in gears 2 through 4. I felt 5 or 6 clear misfires and stumbles, much worse than the slight pulsing normally felt (these were obvious misses and I'm surprised I didn't get a CEL), and I thought s*** that didn't work. I wondered if maybe the .030 gap was too big and that maybe there is a reason the factory plugs are gapped so small. I continued to drive though and subsequent acceleration runs felt very smooth, with no misfires and also no hesitation or pulsing! Seems very smooth now, even at low RPM and WOT. Too early to tell if any change in MPG. As long as I don't experience any more misfires, and there is no drop in MPG, I'll keep these plugs and be happy that the hesitation has gone away. Otherwise I'll put the stock plugs back in. But why would it miss those few times, then run fine? What adjustment would the ECM do regarding new plugs? Think the gap is still too big?


As opposed to installing individual spark plugs wires, working blind with the 1.4. Another reason why I like coating the sides of the boots, not the spark plug tips so they slide on easier. Can barely see that the four boots are centered on the four plugs before pressing down, but have to make sure they are. Then I held my right side up and pressed on the #1 plug first wanting to hear that light click, following with 2, 3, and 4.

Could have been the boots were not fully seated by eventually went down. Really doubt if 2 mils over would make that much difference. Gaps on the Autolites I received were quite large, trick is to bend that ground electrode so it surface is penpendicular to the center line of the plug. I also used a wire gauge, not a flat one. 

Have no idea where these NGK's were made, Japan is doing a lot of outsourcing, worse than us. 127 million people on that small island with also the super rich and most of them struggling to eat. Talk about a corporate ran country.


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## *CraSh (Apr 5, 2012)

Well I finally got around to messing with my spark plugs. Pulled them and gauged them, all factory gapped at .025. I had a lot of hesitation on the highway if I would try to accelerate in lower rpms without down shifting. And the car would almost die trying to leave a stop light with the a/c on. I was going to trying gaping the factory NGK's to .028 first, but the very first plug I broke the electrode off. So I ran down to oreillys and picked up a set of APP3923's and I couldn't be happier. Power, acceleration, and drivability is all better. Highly recommend these plugs.


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## NickD (Dec 10, 2011)

*CraSh said:


> Well I finally got around to messing with my spark plugs. Pulled them and gauged them, all factory gapped at .025. I had a lot of hesitation on the highway if I would try to accelerate in lower rpms without down shifting. And the car would almost die trying to leave a stop light with the a/c on. I was going to trying gaping the factory NGK's to .028 first, but the very first plug I broke the electrode off. So I ran down to oreillys and picked up a set of APP3923's and I couldn't be happier. Power, acceleration, and drivability is all better. Highly recommend these plugs.


This makes two of us, two down and about a million to go.


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## Vetterin (Mar 27, 2011)

So you guys are using the double platimums? I put the Iridium XP3923's in mine and while things seemed good for a month or two they started fouling up after about 4,000 miles. I just replaced them with the original NGK's (with about 36,000 miles on them) last weekend and the car is running much better.


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## boosted__cruze (Jun 25, 2013)

XtremeRevolution said:


> Really...out of 79 vehicles we've had reported, only one of those had plugs that were .028. That's a pretty small percentage, unless you had a dealership check and re-gap them for you.
> 
> Sent from my Bulletproof_Doubleshot using AutoGuide.Com Free App


Im assuming im that one person? Lol

Sent from my beast GS4


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## *CraSh (Apr 5, 2012)

I bought my car new, at 40k now and that's the first time the plugs where ever pulled.


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## AlainSDL (Jun 13, 2013)

XtremeRevolution said:


> Really...out of 79 vehicles we've had reported, only one of those had plugs that were .028. That's a pretty small percentage, unless you had a dealership check and re-gap them for you.
> 
> Sent from my Bulletproof_Doubleshot using AutoGuide.Com Free App


Are you saying that our plugs aren't gaped correctly from the factory?


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## chaser x (Sep 3, 2012)

Will the Autolite APP3923fit on the Cruze LS? if they are that good maybe ill buy a set instead of gaping the spark plugs that came with car.


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## obermd (Mar 3, 2012)

Take a look at the graph on post#16 in the thread http://www.cruzetalk.com/forum/10-engine-technical-discussion/6958-what-your-spark-plug-gap-2.html (The post is on page 2). As we got more plugs measured the peak at 0.025" just kept getting taller. At this time, the official GM maintenance guide for the Cruze was

1.8 (LS) -> 0.028"
1.4T (LT, ECO, LTZ) -> 0.033" to 0.035"

After prompting by Andrei, GM finally responded and their response is at http://www.cruzetalk.com/forum/10-e...cial-statement-regarding-spark-plug-gaps.html, which if you read carefully while remembering that anything a large corporation says in the US is always vetted by lawyers, basically says that we're changing the official plug gap to a range from where NGK is delivering the bulk of the plugs to what we have printed in the owners manual because the engine design team says this range will work. There is absolutely nothing in this response as to what the powertrain engineers said was the optimal plug gap for this engine in this application (car).

In addition to this, the range listed in the response is given in mm and when rounded to the nearest thousandth of an inch, still doesn't cover the gap size published in the 2011 and 2012 US Cruze owners manual.


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## NickD (Dec 10, 2011)

My 2012 owners manual state the proper gap is 0.028 inches or translated to 0.7112014 mm.

"The 2012 North American Cruze Service Manual spark plug gap information was incorrectly listed as 0.85 - 0.95 mm. A change is being implemented to correct that information to 0.6 - 0.7 mm."

So now they are saying the upper limit is 0.7 mm?

And the mean is 0.65 mm or 0.0256 inches?

I am gapped at 2.4 mils too high?

Well not enough for me to panic right now, sure beats when GM came out with that new HEI and recommended 0.0625 for a gap. Guess the wanted you to burn out your new catalytic converter at the same time so you would have to buy a new one with misfires.

Was another bad joke with he newly formed EPA with high content sulphur in the gas. Major exhaust output is H2O and with the high heat of misfires and S created H2SO4 or sulphuric acid destroying our lung tissue. EPA is trying to kill us, but came out with more friendly terms like acid rain or a rotten egg smell.


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## Handles (Oct 8, 2012)

I just replaced my factory plugs on my 2011 with about 55K on the odometer. All were at exactly .028.
I replaced with the autolites listed above and gapped to .032. I have noticed the car bogs down much more with AC on, and I'm averaging about 3mpg less on my interstate work runs. Certainly not happy with the performance.
Anyone suggest re-gapping to the factory setting of .028? (I used the larger gap per comments on this site). 
I guess it would be my only option other than going back to the AC/NGK plug.


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## jblackburn (Apr 14, 2012)

Handles said:


> I just replaced my factory plugs on my 2011 with about 55K on the odometer. All were at exactly .028.
> I replaced with the autolites listed above and gapped to .032. I have noticed the car bogs down much more with AC on, and I'm averaging about 3mpg less on my interstate work runs. Certainly not happy with the performance.
> Anyone suggest re-gapping to the factory setting of .028? (I used the larger gap per comments on this site).
> I guess it would be my only option other than going back to the AC/NGK plug.


Platinum plugs handle heat poorly. You could try regapping but doubt .04" would make a difference. 

Seen the "hesitation gone" thread pinned in the 1.4 forum? 


Sent from Bill the WonderPhone


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## Handles (Oct 8, 2012)

The autolites aren't platinum they are iridium. The direct cross reference from factory plugs. Suggestion?


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## jblackburn (Apr 14, 2012)

Handles said:


> The autolites aren't platinum they are iridium. The direct cross reference from factory plugs. Suggestion?


You said referenced above - Nick used the "aap" plugs. You used the XP?


Sent from Bill the WonderPhone


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## Vetterin (Mar 27, 2011)

After pulling the Autolite coppers gapped @ .030, I've been running the XP's @ .028 and the difference is quite noticeable (for the better).


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## Handles (Oct 8, 2012)

Thanks, I'll give that a try and see how things come out.


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## NickD (Dec 10, 2011)

Wondered what idiot started this post and can't even spell "dumped'?

Ha, looks like it was me. 

Still very happy with my APP3923's gapped at 26 mils. Just pulled into my steep driveway in 1st gear with the engine at idle, purred like a kitten. Starts instantly with just a touch of the key and gets 46 mpg if I can hold it at 65 mph.


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## pL2014 (Dec 29, 2013)

NickD said:


> Also felt the carbon buildup on the tip of the white center electrode was excessive on these NGK's with only 5,000 miles on the plug. Either too cold of a plug, but definitely a sign of misfiring. Use to be able to buy plugs with different heat ranges, that has also become history.


The 2014 Cruze lists the IFR6Z7G which is a hotter plug than the IFR7X7G. Interesting.


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## Handles (Oct 8, 2012)

Handles said:


> Thanks, I'll give that a try and see how things come out.


I finally got around to re gapping the APP3923's to .028 vs. .032. Hesitation is much improved, but still not feeling the same as the stock NGK's, mileage on my work round trips (about 220 miles) is down an average of 1.5 mpg in comparison. 
Thinking of going back to the NGK's unless someone has a better suggestion.


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## jblackburn (Apr 14, 2012)

Handles said:


> I finally got around to re gapping the APP3923's to .028 vs. .032. Hesitation is much improved, but still not feeling the same as the stock NGK's, mileage on my work round trips (about 220 miles) is down an average of 1.5 mpg in comparison.
> Thinking of going back to the NGK's unless someone has a better suggestion.


I really can't think of a reason why, but it seems like the people running Autolites copper 3923's instead of the NGK BKR's are having most of the trouble - I haven't heard reports of the BKR switchers having troubles unless the gap grows too much.

I've always heard that "Autolites are for Fords" (they used to be the OEM supplier), but I have no idea why that would be or if that's just entirely fiction these days.


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## BowtieGuy (Jan 4, 2013)

Handles said:


> I finally got around to re gapping the APP3923's to .028 vs. .032. Hesitation is much improved, but still not feeling the same as the stock NGK's, mileage on my work round trips (about 220 miles) is down an average of 1.5 mpg in comparison.
> Thinking of going back to the NGK's unless someone has a better suggestion.


What about the BKR8EIX? A few on here have switched to it with good results.


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## Merc6 (Jun 8, 2013)

AlainSDL said:


> Are you saying that our plugs aren't gaped correctly from the factory?


Yes, plugs are shipped with cardboard protectors but seem to be gapped extremely close. My gaps were so small none of the feelers could get in to read it. I took the car back to the dealer 3 days after purchase for the issue and CCND was the results. Regapped the plugs .031 but still had issues. Ditched 87 for 93 and had less issues. Went NGK V Power BKR's from j's "hesitation gone" thread and .032 was my set plug gap to maintain up to the point I got tuned. Gap had to be closed back to .028 to prevent blowout and cels from popping up. 


Sent from my iFail 5s


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## gab5 (Dec 22, 2012)

FYI ...I put the Autolite AAPP3923 in my Curze with 1.4L and I started getting misfires after about 8,000 miles. Going to AC Delco-which is made in Japan by NKG from what I have heard. The tips of the Autolite started breaking down and arced the gap. They just seemed to be breaking down. I have 109,000miles on my 2012


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## obermd (Mar 3, 2012)

gab5 said:


> FYI ...I put the Autolite AAPP3923 in my Curze with 1.4L and I started getting misfires after about 8,000 miles. Going to AC Delco-which is made in Japan by NKG from what I have heard. The tips of the Autolite started breaking down and arced the gap. They just seemed to be breaking down. I have 109,000miles on my 2012


Gab,

With one exception, the consensus of our Gearheads is that the NGK BKR8EIX plugs seem to be the best plugs for the Cruze 1.4T engine.


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## Dal (Nov 29, 2015)

my 1.4 has 20,000 miles I am just wondering what plug to get? Also have a 1.8 same question. Thanks in advance!


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