: Compression Ring Treatment



Festus40
09-28-13, 09:55 PM
Has anyone attempted to clean the oil rings by squirting Mass Air Sensor cleaner into the piston tops with the intake manifold removed? I am replacing the plenum and intake gaskets due to lean Bank 1 and lean Bank 2 codes. The shop manual indicates this process is done with the heads removed, but if you can rotate the crank, the intake valves would open and the solvent would trickle down on top of the pistons. Let me know if: 1- It is possible, and 2- It will not hurt the cats in the exhaust system.

Submariner409
09-29-13, 09:58 AM
There is a specific GM process for cleaning carbon from the top two (compression) rings; the third, bottom ring set is the oil control ring assembly. The procedure is done with the engine in the car and assembled. The GM shop removes the spark plugs, inserts a measured amount of cleaning fluid into each cylinder through the spark plug hole (rotating the engine so that no piston is at TDC), wait a specified period of time, vacuum out every cylinder, roll the engine over to clear any excess fluid, replace the spark plugs, run the engine a specified period of time, shut down and immediately do an oil/filter change.

The casual Northsar owner is far, far better off if he/she suspects 'cold carbon rap' to study the Cadillac Technical Archive way up ^^^ in the top black bar - especially the article titled "Occasional full throttle operation is good ...........".

Your car has one catalytic converter - a welded part of the original exhaust system. $1300 if you can find one, or weld in an aftermarket unit and hope for the best. Some get lucky, some have cat code problems after a replacement.

Festus40
09-29-13, 12:51 PM
Thanks Sub..
I knew if anyone would have the "right" answer it would be you.

the recluse
09-29-13, 10:06 PM
Or you could go "old school" and steam them clean with water...I'm sure Sub knows what I'm talking about...

Ranger
09-30-13, 10:05 AM
That is hard to do and somewhat dangerous on these cars. Beside that, the OP said "oil rings". Nothing is going to get down to them, unless he meant compression ring.