Oil leak somewhere on the top end
 

Hi all,

I am hoping for some sage advice.
My 1994 MPV 3.0 4wd has developed an oil leak somewhere on the top side of the engine.
I shampooed then engine to see if I could isolate the source of the leak but so far have been unsuccessful. Currently the oil pools at teh front end in a depression between the distributor(?) and the valve cover and in the same spot on the back side between the valve cover and the block out for where I am thinking the distributor would go if the engine were rotated 180 degree through the horizontal plane.
Is this a common problem?
Could it be a warped valve cover?

The oil tends to drip on a heat shield near the firewall and the fumes enter the cabin when the defrost is on. It is not a significant amount of oil but annoying when the windshield is foggy.

Thanks in advance,
David

The passenger side cyl head distributor blind plug o ring and pcv housing o ring leak where you describe. The same on the drivers front where they use o rings.