Oil leak at rear of valve cover
I've purchased a '92 2.9L in very good condition with 93K miles. Previous owner had every scheduled maintenance done by the dealer and kept every receipt. Twice, over about eight years, she took it in for a small seepage of oil from around the back corner of the right-side valve cover. Twice they replaced the cover gaskets, the second time (500 miles ago) with new-style neoprene. It still has the leak, minor but enough to cause a few drops on the pavement at each stop.
Anyone have a theory on why this doesn't get fixed? Could it possibly signal a slightly warped or hairline-cracked head? There is no sign of oil in the radiator, nor any noticeable loss of coolant. Does this problem ring any bells?
'92 4x4 2.9L regular cab long bed 94K miles.