g'day davis
i would say its condensation i had the same problem recently when i changed my oil when i cracked the drain plug i got about a cup full of clear water then oil no water mixed in with the oil no green so it wasnt from any water leaks & this is a daily driver i havent used it for 2 weeks now & its done it again.
your oil pump if its next to the oil pick up tube on the pump then your oil pressure by-pass valve is missing. hope this helps

moz. geelong victoria australia.
graduate 1980, bus, truck, car, hot rod, boat, submarine, hovercraft, hydrafoil, firetruck, mobile home, jet, helicopter, cruise ship, motorcycle, bicycle, santa's sleigh, clock, alloy bullbar, alloy fuel tank, lens, dr who's tardis, matter - anti matter warp drive buffer & y-block lover