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Combustion chamber cleaning.

11K views 33 replies 19 participants last post by  GTOGRRRR 
#1 ·
I want to do a combustion chamber cleaning. I'm getting some pinging at WOT. Can't stand that!! Probably some carbon on my pistons I'm thinking. Car is an 06 with 31000 on it and I got it at 27500, but I'm the 3rd owner, and no telling what the PO's did, with driving habits and all.
I saw a thread on another forum where a Chevy tech said to removes plugs, fill cylinders with GM top end cleaner, and let it sit over night. Next day crank engine to expel fluid, reinstall plugs, start and let idle for 20 min. Then shut down and change oil n filter. Then go driving!! He said has done this technique with over 50 LS motors and has had perfect results. Only thing is they don't make the GM top end cleaner anymore. I found some new AC delco inj and chamber cleaner at Chevy today, but I'm not sure. Bottle says for pressurized use in fuel rail. I've also heard the Mopar Combustion chamber cleaner is another one being used since the GM product is no longer available.

Anyway I wanted to ask for some opinions if I may.
 
#2 ·
bg induction service done by a recommended shop.

its a piece of equipment that is hooked right up to the fuel rail system.
the vehicle is then ran off of the fuel cleaning chemical they supply.

i have seen this stuff remove a ton of carbon and help vehicles that have been sitting for a long time pass emissions.
i have seen it improve numbers on a 5 gas analyzer.
 
#3 · (Edited)
I've had pretty good luck with seafoam, but if it's really caked on probably need a few back to back treatments (running it in-between)...Plan on changing your oil after you're done though as it has a tendency to contaminate it; not to the point of ruining it, but not a bad idea to change.

What we used to do on carb'd engines (and I've done it to EFI so long as it was MAF and worked best when TB was in upright position) is start the engine, warm it up and hold the rpm's ~2k-2500 and take a squirt bottle with water (yes water) and squeeze it in; turns to steam by the time it hits the comb. chamber, cleaning the carbon out...yes, it works well, BUT you need to use better judgement as too much water too quick will hydrolock your engine, since it's not compressible. However, at those rpm's and a squeeze bottle limiting the flow, it works...for the more timid, you can use a spray bottle 'mist' at a lower rpm, which turns to steam much easier.

Another option is to install a water injection system which uses a hi pressure pump and mist nozzles, so when it hits the heated air stream, it turns to steam...On a forced induction hot side this also acts as an intercooler since that conversion takes away heat of the air...meth injection is similar, but methanol is flammable (alcohol) so it also helps in the combustion side of things. I've wondered how well it would work on a N/A system with it activated as you're cruising down the highway at 2-2500 rpm...it would probably have to be activated manually, since there is no reliable method otherwise unless you did it via rpm, but if you went and shifted it may not stop quick enough...generally it's activated by boost pressure on a turbo or s/c setup...My biggest worry on a N/A though would be what happens if it starts leaking or the vacuum pulls too much water that is still in the line, etc.

Likewise, thought it would be kind of cool to hook up something 'tee'd' off the brake booster line with a container of seafoam attached, so that you can activate it as you're driving...probably cause the engine to stumble a bit, but if you're cruising maybe not so bad, otehr than a big smokescreen, lol.

Problem is being MAF, this is not real practical way of doing things and I would be hesitant introducing water via the vacuum tubing, for control...it may work, but it can be an $$ lesson if you don't do it right. Instead, use seafoam there.
 
#4 ·
I would change the oil before firing up an engine that was drowned in top engine cleaner. Then change it again after the 20 min run time. Then change it again after the road test.

I'd rather do a couple seafoam treatments through the PCV hose over a period of time and slowly work away the carbon, than carpet bomb all the cylinders completely full of a cleaner overnight, trying to undo 31,000 miles of not running a catch can in a few minutes.
 
#5 · (Edited)
I think I would take a look at the tune before I assumed it was carbon build up causing the pinging. Could be timing or fueling related. Who knows... perhaps one of the previous owners tinkered with a handheld and has the tune jacked up.

My pistons had some carbon build up at the time I disassembled the engine. I cleaned them, and that carbon is pretty tough to remove. I had to use cleaners and a TON of elbow grease. I actually said smurf it and left some of the carbon on. I used seafoam before the tear down, and I don't believe that stuff would remove the carbon bonded to the pistons if I soaked them in the it for a year.

Personally, while someone can debate with me about the effectiveness of these engine cleaning treatments, I HIGHLY doubt your issues will be attributed to carbon build up, especially at your mileage level. I think you need to have some diagnostics done to find out what your AFR and timing are doing.
 
#6 ·
Cleaners with PEA are the only ones that clean Carbon well. Seafoam has no PEA in it.

Techron, Redline SI-1 & Amsoil PI have PEA and I have used those with success.
 
#8 ·
I agree it's not that good of stuff. When I did my heads I let SeaFoam sit on the piston's carbon buildup overnight and it hardly touched it. Brake cleaner blasted it right off.
 
#9 · (Edited)
I think a lot of the 'magic' cleaning from seafoam is from the heat, also...I mean, water won't do anything to carbon, but change it to steam and it'll loosen and clean it up just as good as most any chemical.

If any of you guys get weird like me with cleaning things, you'll find out just how much of a difference boiling something in water (and using a soap too) works, then following it up with steam (cleaner), where just applying or soaking it doesn't do much on its own.

BTW - not saying not to use chemicals, but with so many different materials in engines these days, got to make sure it's compatible.
 
#10 ·
I don't doubt that but I wonder if anyone has ever looked at a head or pistons right after a "treatment". Does it do the job? If billows of smoke mean it's cleaning that's great but you can get billows of smoke just pouring oil in. As a solvent it sucks. I tried in on the intake manifold without success too.
 
#11 ·
The OP came in here with the assumption it is carbon build up that is causing his pinging issues. People here are being helpful by debating the best method to remove the carbon, BUT I'm just suggesting there maybe other issues worth considering. My motor had some carbon built up on the pistons without any WOT pinging.

If he started a thread that said, "help, motor pinging at WOT!", I think carbon removal wouldn't be the first suggestion. There is information missing too. Is this car stock? Headers? Tuned? There are other issues that cause pinging. If my motor started to ping WOT, I'd look at tuning related issues first... like a lean condition at WOT for one.
 
#15 ·
totally what he said ^^^^
 
#14 · (Edited)
A green veggie.

I'm assuming he means polyetheramine.
 
#16 ·
I just put heads on my 05 and I was able to just wipe the carbon off the piston tops and combustion chamber with a little PB Blaster on a rag, I don't see how you could have that much build up. I would check the tune? Our car has 42,000 miles on it.

Kevin
 
#18 ·
Did a 2010 Camaro's heads with about 11k miles and I could've get the carbon off all the pistons as hard as I tried. Did heads on a 2005 GTO with 90k miles and didn't even have to clean the pistons off, they were perfect. Unfortunately every motor can be vastly different.

I agree with other responses though, I would suggest looking somewhere other than carbon build up.
 
#17 ·
I don't know for sure it's carbon deposits, but I am leaning that way. The car is stock other than a drop in K&N, and I do have a catch can, but has only been on since 30,000 miles. I wanted to do a combust chambr cleaning first cause it seems easiest. And I wanted to a more aggressive cleaning than just running a cleaner through the TB port. The idea of the chemical sitting on the pistons overnight sounds like it would do more dissolving than having a cleaner combusting in the cylinder.
 
#19 ·
I can see why people dont think Sea Foam works, (its just the Sea Foam smoking) but I used it multiple times on an old Saturn, and the first time I used it it smoked like a sumbitch, and every time thereafter, less and less. Who knows if its snake oil or not. Next time, I would like to try a water solution. Get the GTO engine nice and hot, and slowly introduce water in so it steams. A bit of water wont hurt anything and hot steam cleans just about anything on the planet, except my ass-crack.
 
#20 ·


I actually used GM top engine cleaner, not seafoam.
All I know is it eliminated all the cold start missfires I saw on my DashHawk when I first got the car two and a half years ago.

Steam cleaning is a good option, as is ATF if done carefully.
 
#23 ·
Don't remember the part number, you can easily google it.

I just popped off the PCV tube that goes directly into the intake manifold and sprayed it in there.

When I pulled the heads, the pistons had barely anything on them, so I know the stuff works.
 
#29 ·
If you do try this let us know how it works and exactly how you used it. I would like to do some sort of deep cleaning on my car.
 
#30 ·
I found some GM top engine cleaner part number 1052626, which Is an aerosol spray. This is probably closely related to the pour can of GM cleaner, number 1050002, cause most websites I went to said this product was no longer available.
Anyway, I'm gonna run this stuff through the PCV/tB port and see how things go from there. I'm kinda losing my momentum on doing the procedure I first described. If I have no luck, I WILL do the plug removal process.
 
#31 ·
Just be aware that the O2 sensors and cats do not like that stuff (any comb/intake cleaner really), so you may get a CEL...however, it typically goes off after awhile. Just a heads up so don't be alarmed.
 
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#33 ·
Huh? Carbon build-up can act as hot spots (pinging/knocking, etc.) and staying hot enough to combust the mixture off-timing. We're lucky modern EFI doesn't allow run-on like the older carb'd cars did (shouldn't say doesn't, cause it's still possible, just hard to do), as that was a PITA when you had a lot of carbon build-up and it would stay hot enough to keep the engine running for awhile...you know that junky sound when you turn off the ignition, but engine keeps running, or dieseling.
 
#34 ·
i use Lucas top end cleaner...a little carbon won't hurt a thing...
 
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