Chevrolet Cruze Forums banner
1 - 20 of 31 Posts

·
Banned
Joined
·
10,296 Posts
Discussion Starter · #1 ·
Was getting that hesitation when taking off in first gear, and not nearly the acceleration with that turbo. When removing the plugs, that white center electrode had a brown tint on it, the inside metal shell was black with carbon. What the heck are they doing, adding more carbon to that way overpriced gas we are buying today?

I use ground up walnut shells in my spark plug cleaner, does a very nice job as opposed to using sand, after a couple of blast, looked like a brand new plug. I pretested each plug first with a pressure test, does have a rather weak spark, but the plugs were dying at around 30-50 psi. After the cleaning, gaps never shifted, could hit 100 psi.

More accustomed to cleaning plugs at 30K miles, must be that turbo in the 1.4L that is begging for clean plugs. If I have to do with every 15K now, can live with this, its fun to clean the plugs on the Cruze.

Anyway, that low speed hesitation, like the engine is going to die, is completely gone now and noticed the improvement in acceleration.
 

·
Premium Member
Joined
·
3,975 Posts
Are you using the requisite "Top Tier Gas" or putting fuel system cleaner in every oil change?
 

·
Banned
Joined
·
10,296 Posts
Discussion Starter · #7 ·
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.
 

·
Administrator, Resident Tater Salad
Joined
·
17,545 Posts
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
 

·
Premium Member
Joined
·
25,596 Posts
Out of curiosity, why did you change your OEM NGKs for Platinum plugs?
 

·
Registered
Joined
·
391 Posts
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.
 

·
Administrator, Resident Tater Salad
Joined
·
17,545 Posts
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.
 

·
Registered
Joined
·
594 Posts
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.
 

·
Banned
Joined
·
10,296 Posts
Discussion Starter · #13 ·
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.
 

·
Premium Member
Joined
·
4,646 Posts
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?
 

·
Registered
Joined
·
391 Posts
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.
 

·
Administrator, Resident Tater Salad
Joined
·
17,545 Posts
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.
 

·
Premium Member
Joined
·
1,943 Posts
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.
 

·
Premium Member
Joined
·
6,917 Posts
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.
 

·
Registered
Joined
·
37 Posts
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.
 
1 - 20 of 31 Posts
Top