I found a leak on the driveway near the back of the oil pan. When I checked it out, I found all my oil pan bolts needed to be snugged and one was missing (on the opp. side of the leak.). My question is, which one would leak with the car sitting (it sits a lot), or could both cause a leak when sitting? Also, does anyone know the part number for the front main seal? Thank you.

 

They can both leak.

 

Make sure it isnt the back of your intake manifold leaking and running down. Thats where mine is coming from and its pretty wet between the back of the oil pan and the front of the tranny.

 

I'd bet my house its your intake manifold, I dont care if half the bolts are missing from your oil pan. The infamous LT1 intake leak looks exactly like a rear main. Check REAL close before you go after the wrong problem. The statistics are on my side.

 

I'll take that over pulling the tranny and pan, thanks for the heads up.

 

It's no walk in the park, but a hell of a lot easier than dropping the K-member, oil pan, tranny and flex plate. I believe you have to take off the fuel lines, injectors, vacuum lines. I've read that you use the GM 4 piece gasket set, but ditch the front and rear seal as they tend to push out. Instead you use RTV and when you replace the intake, the car can not start or move for 24 hours. It can leak, till I do the every 100K engine refresh.

 

Out of pure curiosity...what's involved in your 100k refresh?

 

I'm doing the clutch on my car right now and having the tranny rebuilt. Today I just replaced the rear main seal since I was in there. It wasn't leaking but I figured it was a good idea to replace it. Anyway, before I took everything apart I thought that the rear main was leaking but it turns out it's the back of the oil pan. The leak really isn't bad at all (I never found oil on the garage floor) so I decided I might aswell leave it for now and just snuged up the 6 rear most bolts on the pan. They were a tad loose. Hopefully that stops the leak if not I'll have to do the oil pan gasket later this summer if it gets any worse.

 

I already had the engine rebuilt about 70K ago. When it hit 100K again. I was going to have the gaskets, seats, springs, values, rering the pistons, and things like that done. Maybe a bigger cam too!

 

I'll second that 'no front or rear gasket' on the intake, RTV only. And it seems collectively that perhaps not starting the car as suggested for 24 hrs may contribute more to success than anything else. There are lots of write ups on this fix, just look around. My .02.