My 1.8t a4 2004 is leaking coolant. Before I bought the car the thermostat was replaced and I had to replace it again a few weeks after I bought it. It was cracked. It is leaking again. Could this be the thermostat again? What could be causing it to keep happening? Thanks! It looks to be driver side. Ill give it another look after work and check on the passenger side and see if I can find it there also.

 

It could be the J-plug that is right near the thermostat. It should be replaced when you do the thermostat.