My Vette is smoking out of the exhaust pipes under hard acceleration and certainly right after I let off of the accelerator and please note that it smells like burning oil (hence I am guessing there is a little oil getting burnt). I do not see smoke during normal driving, only when I really get on it and when I do, it is not a lot of smoke, but I can see a translucent cloud in my mirrors. Since I did not install afterburners, I believe there is an issue here.

My Vette was not doing this before, but yesterday was the first day that I had the opportunity to really lay into it after my engine mods I did this last winter. I have a FAST intake and the d@mn thing whistles so I recently took off the throttle body to see if there was anything I could trim up that might fix that whistle problem. I noticed that on the inside floor of the intake there was a fine sheen of oil. I know that in the LS1, this seems to be a normal condition but one I thought I should comment about none the less.

What I am hoping right now is that there is a component like the PCV valve or some such thing that may be suspect and hoping that it is not a valve stem seal, and praying it is not a broken piston ring. The engine has 68k on it and has never been raced. The heads are 2004 vintage and I cleaned up the ports and put on Comp Cams beehive springs as well as new valve stem seals so I would like to hope the issue is not internal to the engine.

The smoke is very faint so I am not sure of the actual color, but I can smell burnt oil. I pulled the dipstick, and the oil looks like oil, not the frothy whitish you get when water is in it. I have yet to pull the plugs and see if any one cylinder shows oil fowling.

So does anyone have any ideas? Codes I should be looking for? I really appreciate any help I can get.

Thanks everyone, -blake

99 Hardtop: 243 LS6 heads, LG Pro long tube headers & 3” pipes, FAST intake, Comp Cams XR275HR w/ 1.75 ratio rocker arms, & custom tune. HoK paint Crimson Red base w/ Tangerine color coat.

It doesn't sound good to me. I would start off by doing a compression test, then do a leak down test. Because it sounds like your piston rings are leaking. Leaking top rings will produce blowby into the crankcase, but a scored cylinder wall will allow oil leakage past the oil rings and up into the combustion chamber. And produce a LOT of exhaust smoke.

At wide open throttle, your vacuum drops to near zero, so I don't think it's your valve stem seals leaking. You very possibly have a scored cylinder wall and a compression check or leak down check will reveal which one it is. When you do the compression check, be sure to have the throttle opened.

If you do have a scored cylinder wall, it will probably show up on the spark plugs when you remove them; one of them being noticably wetter or darker than the others.

So does anyone have any ideas? Codes I should be looking for? I really appreciate any help I can get.



I've been told by several people that this is the nature of the engine (especially at high RPM).

It's the value float that causes more oil to be sucked into the chamber.

I have experienced a similar thing. 93k on motor - no mods. Runs puurfect but when I put it under heavy load I get smoke and I've noticed that I consume oil when I consistently get heavy footed. When I go easy, oil consumption is very low - to non-existent.

So the explanation made sense to me - I guess.

Oil consumption is a very common issue with ALL 1997-2002 vehicles with the LS1 Motor. It happens around 3,200 RPM because GM stopped using traditional seals on the valves and went with this weird red composite seal. On one of the valves it did not seal right and thus leaks oil at high RPM. It is much more common on manual cars where the driver goes over 3,200 RPM more frequently. It is not expensive to get the parts but the labour it extremely expensive because they have to drop the whole motor. In the end you will be dealing with about a $1000 job. The General should have recalled the issue but decided not to, most likely because it would have cost them so much money.... which I think is total bullshit.