Problem Description and Possible Solution
On the 3.9L V6, 5.2L V8 and 5.9L V8 the Oil leaks commonly from the valve cover gaskets, intake manifold gaskets (front and rear), timing cover gaskets, distributor O-ring, and the rear main seal area. Using fluorescent engine oil dye can be helpful in determining the source(s) of the oil leak.
Average mileage: 151,166 (51,000–264,000)
Engines affected: 3.7L V6, 3.9L V6, 4.7L V8, 5.2L V8, 5.9L V8
18 people reported this problem
I had no oil leaks from the engine until I decided to change to Mobil Oil's New "High Millage 75k Plus" Full synthentic oil. I knew full well that I would maybe see new leaks after switching to synthetic as I have with most engines after switching to syn oil. I did this only to get the most miles out of my aging high millage engine. Now I am planning on replacing the valve cover gaskets and O Ring on the distributor.