oil leak

on my 98 3.8l i have an oil leak that a mechanic took a quick look and said it was a rear main seal because the oil was near the back of the engine and running down the oil pan and tranny and bottom of the engine and hitting the exhaust and burning...i looked it up online and found that 4th gens "While it was originally thought to be the intake manifold gasket itself leaking, it's now found to be the sealant being used. The reason is a gasket is only applied to the left and right sides of the manifold while the front and back are sealed with RTV sealant. If the sealant is applied to a surface which isn't clean, the oil will be able seep through. This is why the oil leak is usually found at the rear of the engine (dripping down onto the transmission). It can be easily mistaken for a rear main seal leak." according to http://ls1.divetx.org/4thgenfaq.html ...i've had this problem for a long time and there is so much oil its impossible to tell where its coming from and almost impossible to see the rear of the engine....does anyone know an easy way to look and tell exactly where it would be coming from or have had this problem before? thanks for the help!

I would think that seeing the back of the engine is very difficult because of the way its shoved under the windshield but if possible try cleaning up the oil and check it every day and see wheres its building up. Of course I dont know if thats possible because im not familiar at all with the layout on a 4th gen.

If you can reach to the back of the manifold and feel for wet oil at the rear seal of the intake manifold you could eliminate that as a possibility.

i've had a horrible time trying to figure it out...i tried cleaning it up and cant get it clean enough to tell exactly...its not a bad leak...its maybe a couple drops a day...i might lose a quart every oil change or so...its just annoying and i can smell it burning when it drops on the exhaust where it crosses over behind the oil pan....the mechanic didnt give it a good look just said it was rear main because the leak was at the back of the engine.

If you can reach to the back of the manifold and feel for wet oil at the rear seal of the intake manifold you could eliminate that as a possibility.

i just tried reaching back to the back of the intake and i cant get far enough back to really tell....i can get to the top of the back but not down on it to feel for oil and i cant go at it from the side...theres too much junk in the way and i cant see any oil but again i cant see a whole lot of the rear of the intake.

I had the same problem, except that it turned out my pan gasket was leaking. Idk even know what that "exactly" is, but i had it replaced and its fine now. No more oil dripping down onto tranny making a big mess.

If it were a rear main, you'd be losing alot more than a guart an oil change, that's about normal. I'd go with what some of you're own research came up with because there shouldn't be a whole lot of difference between the chevy 3.8 and the buick, and I'll tell you the the buick 3.8 needs valve cover and intake gaskets every 30k. If you're luck, you can get about 50k out of the head gaskets too, but it makes sense to do them at 30 and avoid potential disaster.

If I would have to guess on this one I'd say intake manifold gasket is leaking. I replaced the one on my 93 Z when I had it. Seems that thin oil and the pvc system the camaro's have don't get along. The gasket in the front and rear is only silicon anyway.