Hello,

My son's 2001 A4 1.8T just lost all coolant. Found a hose on the back of the engine that runs from the back upper part of the engine back up into the dash. Very tough to get to, and wondered if any one knows what this hose is...could not get part number, but last three digits are 37H or 371H. It located just left and below the expansion tank.

 

If you are able to, take a picture of the hose in the engine bay and post it up here.

 

Just was able to uncover the part #...it is the heater core hose that goes from the flange on the rear of the engine to the heater core. Part number is 8DO 819 371H.