# Cleaned my spark plugs with only 16,000 miles on them.



## jblackburn (Apr 14, 2012)

What plugs are you running?


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## Diesel Dan (May 18, 2013)

Have any pics of your pressurized spark tester?


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## nodule (Apr 26, 2013)

Wow...shouldnt the plugs be go to at least 60,000 miles??


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## Blue Angel (Feb 18, 2011)

I thought cleaning plugs was a thing of the past... ?

More info and pics!


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## Jim Frye (Mar 16, 2011)

Are you using the requisite "Top Tier Gas" or putting fuel system cleaner in every oil change?


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## NickD (Dec 10, 2011)

View attachment 15605


Ha, they haven't made one like this in the last 35 years. Still works, no one asked if I throw my dirty dishes away either, and much cheaper than buying new plugs.

Using Autolite APP3923 plugs, double platinum gapped at 28 mils. Only gas my Cruze has ever seen was top tier ethanol free 91 octane. Maybe they should come out with super top tier gas.

Didn't take photos of the plugs when I removed them, but did see that brown tint, another thing I didn't do was to check the resistance between the hot and ground electrode using a megaohm meter. Just cleaned them, check the gap and put them back in, with proper torque of course.

Carbon is highly conductive, used in resistors that I have a ton of even in only fractions of an ohm. This carbon will shunt out that high voltage. Been in the habit of using Seafoam every 10K miles to help keep the engine clean. Intake valves can really gather up that carbon. Doesn't help by recirculating exhaust and crankcase fumes either, but is an EPA requirement.

Attempts back in the 70's to eliminate that C from HC was worthless, carbon has a very low heating value and only virtue is making a mess, but can't fight city hall on this issue, or was that the US congress.

If you have single cylinder two cycle motor scooter, chain saw, or outboard engine, can really appreciate the value of having a clean spark plug. Not only burning gas but oil as well.

Can only wonder why the CEL didn't come on, was definitely getting a misfire. Suppose I could pull the ignition system out and run an energy test in the Cruze.


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## jblackburn (Apr 14, 2012)

> Autolite APP3923 plugs, double platinum gapped at 28 mils












Turbocharged cars hate, hate, HATE platinum plugs. The problem boils down to the platinum core inside that heats up and causes pre-ignition, which is the carbon build-up and misfiring you're seeing.

Copper core (Champion or NGK work great) or iridium plugs for turbos. Even iridiums aren't a brilliant choice, but they do last a lot longer than coppers.



> Platinum plugs actually have a piece of platinum in them, hence the name, that heats up very quickly. What this does is help ensure a more complete burn in the combustion chamber, thus reducing wasted gas and in turn, lowering overall emissions. Platinum plugs are great for a stock daily driver, and can last a long time because the platinum gets so hot that it burns up any deposits on the plug; in essence it is self-cleaning. However, on a turbocharged or nitrous application, where you are increasing cylinder pressure and thus, heat, the platinum in the plug can become the hottest point in the combustion chamber and can actually ignite the mixture before the plug even fires. This is called pre-ignition, and actually tries to force the piston back down the cylinder while it's on it's upwards travel. This is not good. This breaks rods."





> The knocking thing is more of an issue for high powered cars (none of which you will find platinum plugs on though ). The common stumbling/stuttering issue is simply because they are piss poor conductors, and result in a weak spark. On a typical NT car, you dont need a ton of spark and the gains in life expectancy outweigh it anyway. On a turbo car, the mixture is much denser, and therfore harder to get a spark to jump through. The better conducting copper plugs privide this power, at the expense of a shorter life. Change your copper plugs every 30k miles at the most.


Platinum Plugs Missing On A Turbo Engine - FWD/AWD 1999 - 2010 - Volvospeed Forums

Never run Platinum plugs under boost?? Why? [Archive] - SupraMania

info on why turbo cars dont like platinum plugs Off-Topic - Car Questions, Answers, and Discussion

Platinum plugs on a turbo? - PT Cruiser Forum


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## obermd (Mar 3, 2012)

Out of curiosity, why did you change your OEM NGKs for Platinum plugs?


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## The_Madcat (Oct 6, 2012)

obermd said:


> Out of curiosity, why did you change your OEM NGKs for Platinum plugs?



Confused here as well. I replaced my OEM ones with other OEM ones - just wanted an extra set to play around with gapping. Not sure why you would go from iridium to plat though.


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## jblackburn (Apr 14, 2012)

I've been running coppers for 5,000 miles (I was having issues with stumbling - more related to a bad ECU program than the plugs themselves). I pulled one out when I was changing the transmission fluid a few weeks ago - gap is still where I set it, and the plugs look clean.

My iridiums are still sitting around somewhere, and they look brand new @ 10,000 miles.


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## Diesel Dan (May 18, 2013)

NickD said:


> View attachment 15605
> 
> 
> Ha, they haven't made one like this in the last 35 years. Still works, no one asked if I throw my dirty dishes away either, and much cheaper than buying new plugs.


That is sweet!
I've seen some old diagnostic equipment over the years but never ran across one of those. That would be cool to have around to play with. Good move using the walnut shells instead of sand.


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## NickD (Dec 10, 2011)

NGK's IFR7X7G that came with the car were really crap, clean and properly gapped, those APP3923's made a world of difference. And yes they were perfectly clean at 10K miles, even at 15, 750 miles. Maybe we should be blaming this oil pipe line problems instead of the plugs.

Even read on one of those sites about another guy with a Supra where is car like mine came with double platinum plugs. And will contact Autolite on this subject, because this is the exact plug they recommended for this Cruze. They are working great again. And that is ALL I did!

Fleet Farm was my favorite place for buying plugs, use to have a 40 foot aisle for Champs where every plug had three heat ranges you could select for your driving habits. Today, that is cut down to about five feet with a terrible selection. Dealers are robbing us to death now after this crunch. Only way to buy plugs now is over the internet.

I will certainly look further into this. Owners recommend Delco 41–117 Part number 55576026 iridium spark plugs, how come my Cruze didn't come with these? Really can't say my history with iridium needle point center electrode has been that great.


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## Blue Angel (Feb 18, 2011)

I wonder if there's some sort of chemical interaction between platinum and combustion gasses that would require the core and tip of the plug to run hotter than an equivalent iridium plug design?

Looks like copper is the best heat and electricity conductor, but attracts the most deposits and has the highest rate of tip wear.

My experience with plugs is, if they're not excessively fouled and the only issue is tip wear, closing the gap back to the desired spec usually puts them back into service with no compromises. Having said that, even with platinum tip plugs I've rarely had to close gaps, even with plugs that have 100k kms on them.

Hey j, which copper plugs are you using? Are you using teh same heat range as the OEM iridiums?


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## The_Madcat (Oct 6, 2012)

The plugs I pulled out at 8k miles (stock) were clean and gapped where I left em. I don't think there is a problem with any oil line so much as the plats are not meant to be used in this application. Just my 2c since I haven't heard of others having to clean the plugs. You may be the only 1 I have heard of that use the plat plugs.


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## jblackburn (Apr 14, 2012)

The stock NGK plugs are a "7" heat range by their designations (on the colder side).

http://www.ngksparkplugs.com/techinfo/spark_plugs/partnumberkey.pdf

I went with NGK V-Power coppers *(**BKR7E)* in the same heat range.

Heat ranges BETWEEN different types of spark plugs _*DO NOT*_ compare easily without a lot of research, so I figured...keep it simple 

Plus they were cheap and let me rule out that it was the spark plugs and fuel causing my hiccups in power.


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## Vetterin (Mar 27, 2011)

Replaced my plugs at 35,000 miles with Autolite Iridium XP3923's from Menards, $3.99 on sale plus a $2 rebate. So for $8 and 5 minutes work I'm good for at least another 35,000 miles. FWIW the NGKs are still fine so a change is NOT necessary at this mileage.


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## spacedout (Dec 7, 2010)

I've always heard ethanol is great at cleaning fuel systems, wonder if all that non-ethanol gas is part of the problem. I too run no ethanol gas about 80% of the time, but always notice the car seems to run smoother after a few tanks of ethanol gas.


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## alyupe11 (Jun 9, 2013)

Interesting


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## v8318cid (Oct 3, 2012)

Non-ethanol gas is very hard to come by around my area so I'm stuck using what is available. I tend to favor Shell since it is better quality from what I can tell than most of the other vendors. What really irks me is finding out that pumps that advertise 10% or less ethanol have shown as much as 18% on my Silverado based upon scan tool readouts. As a result (in my opinion at least), both my Cruze and my Silverado have been building up carbon deposits and the Cruze specifically lost something like 10 mpgs average at around 20k miles. I've had to run Sea Foam through both to remove spark knock and, in the case of the Cruze, restore fuel economy.


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## NickD (Dec 10, 2011)

Became interested in Champs again, while I can find selection guides for any other brand of plugs, could not find one for Champion. Am I going blind?

Can only wonder who is making Delco plugs, trying to remember the exact year GM sold Delco to a group of private investors. But didn't last very long, they couldn't even pay the bills at the prices GM would pay them for all Delco parts. Was sometime in the early 90's. Did the same thing later with Delphi to yet another group of investors. But do know GM did maintain the rights to use the Delco Remy name.

Charles F. Kettering was my hero, being the first to invent the ignition systems, self starter, and generator. Sure, transistors are used today, but the principles he developed are still the same. Even Henry Ford was envious, but stuck with his vibrator ignition systems for the Model T and a hand crank. But finally incorporated all that in the Model A when Kettering's patent were expired. He refused to pay a few cents per vehicle in royalties.


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## Patman (May 7, 2011)

obermd said:


> Out of curiosity, why did you change your OEM NGKs for Platinum plugs?[/QUOTE
> 
> With my 1.8 I changed my original plugs for Autolites and then ended up replacing them with OEM again. Yesterday I found ACDelco 41-121(NGKs) from RockAuto for 5.69 ea. 10.50 ea at the dealer. Pre gapped. Now my Eco I bought another set to "play with the gap" and now wanted to go back to OEM AC Delco 41-121. That after replacing the new plugs(41-120) with original(kinda carbon fouled) to see if it helped the compression issue. It seemed to so I found the ACDelco 41-121(NGKs) from RockAuto and bought them. Besides I want new plugs for the tune.


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## Diesel Dan (May 18, 2013)

NickD said:


> Can only wonder who is making Delco plugs,


Yeah, it has been a long time since they were made at A/C spark plug in Flint Michigan.
Same with AC Delco oil filters, just farmed out to the low bidder. I used to be a big AC filter fan but now I mainly use WIX or Fleetgaurd.


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## jblackburn (Apr 14, 2012)

spacedout said:


> I've always heard ethanol is great at cleaning fuel systems, wonder if all that non-ethanol gas is part of the problem. I too run no ethanol gas about 80% of the time, but always notice the car seems to run smoother after a few tanks of ethanol gas.


Little to nothing to do with it. His plugs are just fouling up because they're pre-igniting or the incorrect heat range for the application.



> Became interested in Champs again, while I can find selection guides for any other brand of plugs, could not find one for Champion. Am I going blind?




You'll want a *7 or 8* heat range with Champion plugs to match the 7 on the NGK plug. Might be better to err on the side of colder and go with an 8 to avoid pre-detonation. 

_* Use a copper or iridium plug. *_ Or just put the NGK Iridium back in and make sure they're gapped correctly (.033-.035" seems to work best for the 1.4 on stock tune).










Heat Range Conversion Chart


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## NickD (Dec 10, 2011)

About the only thing more I am going to say on this subject, its an absolute pleasure to change plugs on the Cruze. Even after major surgery.


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## Blue Angel (Feb 18, 2011)

Question for those who are tuned... what are the recommended plugs and gap when tuned? Heat range? If I'm remembering right, are people just using the OEM iridiums with a little tighter gap, around .028"-.030"?


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## H3LLON3ARTH (Dec 16, 2011)

Blue Angel said:


> Question for those who are tuned... what are the recommended plugs and gap when tuned? Heat range? If I'm remembering right, are people just using the OEM iridiums with a little tighter gap, around .028"-.030"?


Your correct.

Sent from AutoGuide.com Free App


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## obermd (Mar 3, 2012)

NickD said:


> About the only thing more I am going to say on this subject, its an absolute pleasure to change plugs on the Cruze. Even after major surgery.


I have to agree with this. My previous cars required you to be a contortionist to change the plugs.


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## Blue Angel (Feb 18, 2011)

For anyone interested, here's a good read for spark plug info:

NGK Spark Plugs USA

I learned a thing or two about heat ranges reading through that. It also makes obvious some of the variables and compromises that are being balanced when designing an engine that operates under such varied conditions... please don't take for granted the level of work involved in producing something as complex, flexible and reliable as a modern car engine!


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## Blue Angel (Feb 18, 2011)

jblackburn said:


> The stock NGK plugs are a "7" heat range by their designations (on the colder side).
> 
> http://www.ngksparkplugs.com/techinfo/spark_plugs/partnumberkey.pdf


Here's a link to a more comprehensive NGK spark plug number reference:

http://www.ngksparkplugs.com/docs/tech/design_symbols_plugs.pdf

For example, the spark gap designation table on this one goes to 6, and also says a 7 (Cruze plugs) are intended to have a gap of .028" as delivered. Reading through their FAQs, they recommend maximum gapping as +/-.008", so a range of .020"-.036". Shhh... don't tell anyone, I'm running them at .038" right now...

...FAQs are here:

NGK Spark Plugs USA


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## NickD (Dec 10, 2011)

See Harbor Freight is still selling a spark plug cleaner for under 18 bucks.

Pneumatic Spark Plug Cleaner

Did find a real old board on the Edmund J. Widel Vixen I have with complaints about using that coarse hard sand on that porcelain that gathers new carbon like crazy. Guess they haven't heard of finely ground walnut shells. And only a two second short blast cleans that off without damaging the porcelain nor the threads or the electrodes.

From viewing the photo of that Harbor Freight unit, I think they are also using ground walnut shells for the media, but can't tell for sure, they don't mention the name of it.


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