Hi everyone,

I've been away for some time Anyway, my 2001 C5 was apparently the test mule for re-ringing 2001 LS1's that ate a lot (I mean a lot ) of oil. I picked up my new 01 C5 in the first batch of cars built for that model year , recieved the car in mid-late July, and broke it in for 500 miles. After 600-700 miles were logged, I dyno'ed the car (numbers were normal - 312 RWHP, 328 RWTQ) and threw a low oil level once finished with three pulls... This was the start of about 6,000 miles of arguing with GM service over oil consumption and having them do 8000 miles of oil consumption testing. From that point forward, the car would consume over a quart every 800 miles. I was told this could be normal but I bitched enough that apparently they either got sick of me or I pursuaded them to fix it. They found 3 of the rings via a leak down test, to be bad, and thus reringed the motor. I have put another 5000 miles on the car and the oil consumption is gone now but I still do notice some oil on the back side of the TB - likely due to PCV (I need to build a trap).

The thing that bothers me is that despite all of this oil consumption, they never bothered to clean out the motor even though they had to pull it to re-ring. I had to replace the plugs, which were oil fouled in those three cylinders. That said. the car has never run quite right after this whole "issue"... It does not throw codes but a few things are oddd:

1) The car, when slowing to a stop with the clutch in, like to try and die on me - I'm told this is normal - BS!

2) The car seems to have an intermittant misfire - as evidenced by the popcorn pop of the exhaust

3) The car does not have the part throttle pull it once had

4) The car runs very rich - it stinks of fuel.

My question: Can oil consumption be bad enough to damage downstream components like O2 sensors that might cause any of these symptoms? Or can enough oil residue still be in the combustion chamber to lead to any of these problems?

I'm going to check the plugs and wires for a bad connection as this may be the misfire, but I am clueless with regard to 1, 3, 4. I've read that air leaks --> 1 but I have none (I've checked).

Will a decarbonization be of any value? Any ideas what might be causing these other problems? Is there one cause or is this multiple things?

Mods: B&B TrifFlo exhaust, Halltech CF bridge + K&N concial filter.

Thanks,

Bob

 

Ok....well first of all let me just say there is NO WAY I would accept that car as is....it sounds like the car needs retuned and the idle reset for one but that may be a result of the misfire you described which could be fouled plugs or possibly a bad wire (can't tell by just looking) OR they may have not gotten some things tight and you are sucking unmetered air at the airbridge which will cause it to run like crap....as for O2 sensors I guess its possible so I suppose you could get under there and look at them.....I would also beotch scream and holler until I got a extended warranty on that car paid for by GM for 100,000 miles.....you can do it...I know 2 people personally that have....whatever you do don't let up......good luck

 

oh yeah...lots of guys here have switched to the German Castrol and solved oil use problems....but it has to be the German version..

 

The excess oil could have very well damaged your cats. This could explain some of your symptoms.

Tino