Some background...

I have a 2000 MN6 Vette (137,000 miles) that has been leaking a fair amount of oil and is ultimately making its way onto my exhaust. After some longer drives, the smell of burning oil is evident. When I pop the hood a can see a small amount of smoke coming up from the backside of the engine.

Here's the most obvious things I've addressed so far...

1.) Started with a fresh oil change and replaced the oil drain bolt. New one has an integrated rubber seal.

2.) Re-torqued all of the oil pan bolts. None of them seemed obviously loose.

3.) Replaced the entire PCV system. GM sells the entire assembly, hoses and all.

4.) As a precautionary measure, I pulled the intake manifold to closely inspect the oil pressure sender and the cam position sensor for obvious signs of oil leakage. Everything looked bone dry. Since I had gone through the effort of removing the intake manifold, I installed a new oil pressure sensor anyway. I ensured it was fully seated any torqued properly.

5.) I raised the car and thoroughly cleaned the areas that were wet with oil. I drove the car for a day and had a quick look underneath again. The oil pan looks dry, however, the oil seems to be collecting near the rear of the engine/bell housing. From there, the oil is being sprayed back onto the exhaust from air turbulence while driving.

So, I'm leaning towards a rear cover seal or less likely, a rear main seal. I also haven't completely eliminated the possibility of the cam position sensor leaking at a spot other than right out the top.

Although, I don't consider this leak to be a major issue, I also don't want oil burning off of my exhaust. Obviously not the safest of situations. The smell of burning oil is also pretty embarrassing at local car shows.

Being that this car is getting up there in mileage, these things are bound to happen. However, if something like the rear main seal or rear cover seal is leaking, I can not justify the time/cost associated with their replacement. Again, it's really not hurting anything.

Any input, ideas, or next steps would be greatly appreciated.

Best Regards,

Derek

 

You are right on with your diagnosis so far. Either rear main or rear cover is
probably the culprit as you have addressed the other point that usually leak

 

Replace the rear main and rear cover seals. To get a better idea of the leak remove the clutch inspection plate which requires the removal of the exhaust.

At 17 yrs old and 137k they are done. While you are in there also replace the clutch, slave and pilot bearing. Add a remote bleeder also.

Doing all of the this right now on a 99 FRC, the rear main although not looking bad was seeping. It is about a 2 day job as a DIY project. You will need a couple of friends to help out with the drive line removal.

Gary