I have a 2004 LS1 and its puffing black smoke under WOT.The turner said it was OK, but the smoke tells me something different is going on. In addition the oil turns black with in 200-300 miles. The motor runs great and the two plugs I checked (1 and 4) looked normal. When it's idling with garage door open, the fumes sting your eyes if the tail pipe is pointing into the garage.

Also, there is hardly any blue smoke at all unless the motor is reved up over and over and then only a small puff may appear.It seems to have blow by, but it was re ringed two years ago. It is definitely running too rich which maybe washing down the cylinder walls. Any help would be appreciated. I checked for PCV trouble, but it has the LS6 lifter cover as a baffle and the throttle body vacuum line draws well, but maybe ineffective. I don't know, but I do know the oil quickly turns black. Need some help.

 

Does the car have a stock cam? If not, what does it have? Do you have access to tuning software to monitor fuel trims?

I would check vacuum lines and top end gaskets to see if the car is trying to add fuel to combat a lean condition caused by a vacuum leak. Next, I would change injectors in case you have a leaky injector.

 

Good point but the vacuum lines are not leaking. i have no access to tuning software. I took the car to the tuner earlier this summer after I saw the tail pipe puffs. He stated the tune was ok and I have known him for over 10 years. I told him about the black oil and he said it was probably due to the 2nd ring. I didn't tell him it was re ringed last year. The engine re ringer thought the problem was with the tune. It uses alot of oil and yet it isn't a smoker??

 

I did not mention it has a 226 232 578 585 115 on a 111 CL.

 

You may want to ask your question in the tuning section. It’s a good size cam, if you’re getting reversion it may be the culprit.