I recently had a somewhat similar experience with my 02 4.4 with 150k miles on it, but with a little more smoke. After (too long of a story to get into) some investigation, I found that the oil return hoses (2) that come from the "Crankcase breather valve" and the "Oil Separator" mounted on the rear of the intake manifold, that return oil to the oil pan had deteriorated causing all sorts of havoc. This is an inexpensive repair, but a little involved to locate and get to. Good luck!