There is some oil leaking onto the starter/starter area, possibly from just above it on my 2002 f250 7.3 liter. It's not quite enough to make a drip, bit the area is wet with oil. There is quite a bit of dried oil that has caked on over the years.
What appears to be some sort of breather hole just next to the oil pan, is where I think the oil is comming from. I don't think it is the rear main seal, I just had the transmission rebuilt and a new seal put in (or so I'm told) I have had the high pressure oil pump replaced, oil pressure lines and fittings replaced in recent the past, 20k miles ago.
your valve cover bolts may need tighing up.
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