Oil Leak AAN Engine - 94 S4

[b1biker at aol.com]

 I have suddenly developed a significant oil leak from the left side of the engine. I'm looking for any assistance in identifying the source of the leak as I don't have a Bentley for this vehicle. There is a large sending unit on the side of the block just above the rear of the A/C compressor; I'm assuming that this is the oil pressure sending unit. Above that is another sensor with a single wire running to it; It appears that this sensor is the source of the leak. If anyone can identify the sensor so that I can get a new one it would be greatly appreciated.
Gary Meier
885KSQ - 94 S4