Hey I was diggin around looking for my coolant leak and ended up pulling off this, I have no idea what it is and the two lines connected on either side were filled with gunk, looks like water and oil.

 

Bump!

 

what engine do you have, it looks the crankcase breather hose on the V6 (im sure the 1.8t has the same thing) it is oil and water (water from moisture buildup not the engine, hopefully) just replace with rubber hose or get the oem from napa or audi. they get brittle over tiem and break it happens.