Ok, so i'm burning about 1/2 quart of oil on my '97 LT1 per week(300 miles). I disconnected the exhaust from the headers, so I was just on open headers(had some exhaust leaks to fix). I fired the engine to see what side the oil was burning from, and it is the drivers side. I pulled out the spark plugs one by one, they all look excellent, and do not have any oil on them whatsoever. I thought it could have been a broken ring for how bad it smokes, but it's not a ring. At this point i'm almost 100% sure it is one of my valve seals that has gone bad. I believe this to be true because the oil is not getting into the cylinder, it's only going out the exhaust. I don't know how to tell what cylinder it is coming from. I know you can replace a valve seal with the head still on the engine using an overhead valve spring compressor. Has anyone used these, and has anyone had this problem with their LT1? Should I replace all four exhaust valve seals or what? This is a fresh rebuild, and every seal is new. I've done some pretty extensive online research, and it sounds like damaged valve seals are very common on the LT1 engine. Also, the smoking will happen mostly on startup, but it will smoke for 5 minutes after the car has been started and warmed up. When driving the car there is no smoke evident behind it, but you can smell it faintly. I'm pretty sure that one of my cats is now destroyed because of this, because it has sort of a rotten egg smell to it (running two cats). I really need all the help I can get on this one guys. Thanks in advance.

 

Sounds like the valve seals , I have done springs seals etc. with the heads still on its some work but can be done . If it was me i would change all if your that far why not . The heads on the car are they rebuilt or used ? seems strange a rebuilt set would be having seal problems right away . You will also need a air compressor etc. to change out the seals to keep the valve from dropping .

 

I talked to my engine builder yesterday, and he is telling me it is way more likely that it would be an intake manifold gasket rather than an exhaust valve seal. I pulled the intake yesterday, and didn't see anything that looked to me like for sure it could have been leaking. I'm re-installing the manifold today and i'll wait a day or so before I fire the car again to give the sealant time to cure. If that dosen't do it, i'm gonna do some exhaust valve seals. I know about the air pressure in the cylinder, thanks for the tip. The heads were completely rebuilt, valve job, resurfaced, new valve springs & seals. Can't imagine them leaking but I guess anything is possible.