Originally Posted by John Fiammetta

If it’s the same side , bank of the filler cap ? Then maybe some oil got split at the last change and with time spread out as it descended.

I once knocked the funnel out doing a oil change and lost maybe 1/2 to 1/4 cup full down the side .Obviously tried to mop up what I could get at there and then .How ever over the coming months oil dampness started to emerge lower down in all sorts of places .This mimics leaks .

A pre purchase inspection would have been grim reading .