Just purchased an 02 A6 2.7T (first Audi). Didnt seem obvious at first but am noticing coolant reservoir keeps emptying in about a weeks time. No visible leaks or puddles of coolant under car. Is this a head gasket issue? Also diagnostic check indicated:
17819-Secondary Air Injection System; Bank 2: Insufficient Flow
P1411-35-10 - - intermittent
Could this cause coolant evaporation?
Any info would be appreciated.
Thanks,
DJF

 

The code is for the air pump mounted at the rear of the motor and should not be causing a loss of coolant.

You do know that audi's use a "special" coolant? Besides not working well with other types of coolant, when it leaks, it turns to a whitish/pinkish powderish "stuff" that gets all over. See anything like that?

My car had a coolant leak that did not drip to the ground, at the Aux water pump. (An electrical pump mounted UNDER the intake manifold that pumps coolant through the turbos after the car has been turned off.) It is almost impossible to see without disassembling the motor.

 

Thanks Mike. No powdery residue. How did you determine the aux water pump was at fault?