OK, I know it's not a camaro. I have a 1993 lumina, 3.1 v6. It's leaking oil, and it looks like it's coming from somewhere near the rear of the engine. It sits there, and dribbles down the side of the block.
The other odd thing, is that it has the distributorless ignition, but it still has a port for a distributor on the manifold that is blocked off.

What is the most likely cause of this leak?

And do these engines have a one-piece intake manifold/head gasket?

Thanks!

 

rear main seal, rear main seal, la la la lala

 

My parents 3.1L Grand prix is leaking oil, simular to what you are saying. It is an o-ring that lives under the distribitor plate(where teh distribitor is supose to be). The O-ring drys up, then the car begins to drip out oil, not alot, but enough to have a leak.

 

If it is in fact the "oil pump drive"'s O-ring, there should be oil on top of the engine. That's not actually a block-off plate; it's the bottom half of a distributor, with a gear on it. The gear connects the cam shaft to the oil pump, just like the gear on a distributor. The o-ring used on our f-body's 2.8/3.1's is a "one inch inside diameter O-ring", found at any "real" parts store.

What do you mean by one-piece intake manifold/head gasket? There's two head gaskets for head-to-engine, one on each side; and there's two intake manifold gaskets for intake-to-head, one for each head. RTV should be used on the "china wall" gasket area; that's the front/back of the intake manifold, since those areas are mismatched. For the head gasket replacement I did on a friend's 2.8, we used Permatex's Ultra Copper for the china wall area, and extended the ultra copper bead to go around the coolant passageways of the head.