[s-cars] Oil Leak - Driver's Side of Engine

[Tom Winter]

OK, so if I had a Bentley, I'd know the answer. But I don't and I have you
guys, which is better than Mr. Bentley any day.

I've developed an oil leak from what appears to be some sort of sensor
(pressure or temp?) that resides approximately halfway down the engine block
on the drivers side. A single wire exits from sensor, which has a white
"stem" kinda like a spark plug. Victim is a '95 S6 Avant.

What is this, and could it be the source of my leak? The "sensor" is
directly above a "plug" which has a hole for a hex. Plug is not the source
of oil, at least it doesn't appear to be.

Other thoughts, info, considerations for repair/replacement of guilty part
also appreciated.

Thanks in advance for all your help and advice!

Tom '95 S6 Avant