I have a 2001 Monte Carlo SS w/ the 3800 V6. I've recently noticed a little oil pooling and sludge on the top of the engine in the valleys between the valve covers and intake manifold. I'll also occasionally get a oil smell in the cabin. At first, I thought it was the UIM gasket since there appears to be some oil around the seam and it looks like a plausible source for the leak. However, after a lot of reading, I can only find reference to coolant leaks from this gasket -- not oil. Could it be oil leaking from the valve cover gaskets instead, or is the UIM gasket still likely?
I just changed the oil and didn't notice any coolant in it. Also, I haven't noticed any coolant loss or any oil in the coolant.