Hi guys, I have a 2006 a4 avant quattro 3 litre diesel, I have owned the car for the last 2 years. It has now got a coolant leak and need to order the part for my mechanic to fit it, I just can't seem to find it as I am not 100% sure what the part is. It is located on the drivers side at the bottom of the engine and seems to be attached to the inside of the body of the car by a little bracket, I have been told its part of the heater matrix but again not 100% sure. It's the metal pipe that comes from the elbow that is leaking in the pictures, I am new to forums but I will do my best to get back to you all, cheers.