I talked to a Cadillac mechanic at my local dealer, and he said that they do not use the rubber gaskets anymore, due to they did not work well, now they use GM Sealent #12378521 in place of the gaskets, for the half case and the oil pan, he said that most oil leaks come from the oil manifold and it must be replaced if leaking. the parts department had a whole lot of them in stock, so the parts guys said it must be true, since they had so many in stock.

I have pulled the 4.6L engine out and my engine does leak between the oil manifold and the lower block, badly. (like a 1 Qt. a week).

what do you guys think?

I bought an oil pan this year for my 95 ETC, it came with a rubber gasket.. I dunno.

What I was doing when the engine was in the car, I added the oil dye and each night I would look to see where the leaks were and slapped RTV all over it, this helped slow it down, or moved the leak to a new place, I repeated every night trying to slow it down to something I could live with.

I did find that 4 pan bolts were stripped, and I drilled and tapped to a bigger size, 8mm x 1.25 x 30mm that seem to help a lot.

but in the end I have to fix it right, once and for all.