Hey guys, my car has 118k, at 115k I seafoamed the engine because of an annoying "ping" under load (p/t accel & on uphills). The seafoam really didn't help. I have since replaced the fuel filter, spark plugs, and k&n air filter. I checked the fuel pressure and I have a steady 58psi. Someone told me that with that kind of mileage, I probably have massive amounts of carbon build-up in the combustion chamber, and that I can try going one step colder on the spark plugs....right now I'm running stock ones. The spark plug thing seems like a band aid for the real problem. What else can cause spark knock? Can an O2 sensor cause any problems with throwing a code? Can someone offer anything because me...and all the local shops...are stumped on this matter. I'm asking because I want to send my pcm in for custom tuning, but want to get rid of the PITA spark knock first.

Also, someone else told me that another way to clean out dirty combustion chambers is to run a few gallons of aviation fuel in the tank, mixed in with the regular fuel, of course. They say that there are no additives in aviation fuel and therefore burns very, very clean. Can anyone offer any insight on this?

 

do you have a oil catch can? to keep oil from going into the intake, that should help alot.

between that, seafoamed twice, new plugs, new o2 sensors I hope that my pining will go away. I also cleaned my maf with a good spray cleaner also.

I did headers recently so I plan to get dyno tuned eventually so hopefully between all that i hope its gone.

colder plug is not really a band aid, but i agree the engine should run completely fine with regular plugs.

i also seafoamed my gas tank also so I need to throw in my other fuel filter, also make sure you air filter is clean also.

i showed my local performance guy my older plugs and he said it was pinging just from seeing the plugs and he remember it was when i dynoed my car awhile ago.

 

I am unfamiliar with this....can you elaborate?

 

Did you run the Seafoam into the vacuum with the motor running? If no do that. If yes do it a couple of more times. If that doesn't get it done then you might have to pull the heads and physically scrape the carbon off.

Maybe check with a GM dealer, they have a top end cleaner that might work.

 

I agree that it might be a PCV issue. Pull your TB off and see if there is oil in your intake.

 

yes, I did. I followed these step-by-step instructions......

http://www.ls1tech.com/forums/showthread.php?t=534376

Is that ok? Isn't too much too soon not good for the engine?

I was hoping it would not come to that.

I will never take my car to a GM dealer again.....I'm tired of them trying to rip me off.

 

Can someone tell me what an oil catch can is?

 

Av fuel will ruin your o2 sensors because it's leaded.

 

^thank you....you just saved me a lot of money

 

New plugs do0d... Gapped at 55. NGK T55's are a good stock replacement.

I really don't think oil consumption is a cause of bad ping.. unless your cylinders are carbon deposited beyond belief.

A catch can is a 'can' mounted between the TB and the PCV valve to catch oil that would have been consumed from the valve covers thru a lot of intake vacuum at high RPM's..

Thunder racing has them..

 

you can make your own catch can out of a air compresser moisture filter, it is really cheap. I saw one at Harbor Freight for 15 bucks, and it even has a little screw at the bottom to drain the oil out.
Gm also makes a different PCV valve that doesn't have the part in the middle, juist a small hole so that oil has a harder timne gettting through, it was put on the trucks and I think Corvettes to stop this oil sucking problem. I bought mine for 6 bucks-different dealers have them for different prices. Before I put mine in, my throtle body was covered in oil, now its clean as new, but I still might try the oil catch method because I've heard of people getting retarded timing even though there wasn't audible knock. I'd leave the stock PCV and do the catch thing.
Also what kind of gas do you have in your area, in California my car pings on 87, but not 91. In Michigan I can run 87 no problem, so if your state has the crap gas like Cali, this might cause problems.

 

Thanks for letting me in on what a catch can is. I replaced the STOCK pcv valve (118k miles on it) the other day and it helped more than I expected, but it's still there. I will try new plugs, again......and the catch can too. Will there be instructions on how to route the hoses for it?

One more question....are the NGK T55s platinum plugs? Are there better plugs out there?....for a stock engine?