'94 E320 W124 M104 with 168,000 miles. Daily driver. Still runs reliably, but this oil leak has me bewildered.

History of this leak - See this post and this one and these pictures and video of leak. (these are all before pictures, everything is clean now. Sorry for the rabbit trail ) Originally thought/assumed it was rear main seal.

Removed oil filter stand and cleaned, replaced gasket. Polished up all surfaces mirror smooth.

Filled with oil, buttoned up and started, and LEAK IS STILL THERE AND FILLING UP TRANSMISSION BELL INSPECTION PORT. Only this time its new oil, not old.

Oil is running down drivers side of the bell housing - SAME PATH.

WHAT is on the rear drivers corner that could be doing this? Leak is a significant one. It's very difficult to inspect even with a mirror.

Since I've super cleaned EVERYTHING plan on getting back under while running to see. After reviewing the oil flow diagrams I really don't see head or other oil galleys in that back corner. And even if it was the head gasket, oil would run down to the oil pan while parked, but this oil continues to stream while running, but continues to drip/seep out all night (alot!). So either the oil filter's backflow check valve is keeping the oil filter unit pressurized, or its the rear oil pan... aggghhhhhh

My next suspicions are:
1. Could the POSITION SENDER UNIT-HFM (part no 003 153 01 28) leak oil?
2. check the oil filter housing CAP. It has a new (dealer) filter and gasket, but maybe its cracked.

__________________
"Well, once again, we find that clowns and anarchy don't mix..." - The Tick
'94 E320 ~ Wikel
'87 300SDL ~ Frieda
'87 190E ~ Thurmond III
'84 944 ~ Schrickelgruber
'86 535i ~ Joerg