My 1999 A6 Avant is not warming up correctly. I can drive 15 - 20 miles and the needle doesn't budge off the left (coldest) peg. I haven't had a reason to drive any further, but the car use to warm up to the correct operating temp within a few miles.

There is one factor that is different since I remember the car warming up correctly, and that is - I had a new auxiliary water pump installed. I don't think this is a factor, but I'm not sure and am hoping someone can point me in the right direction to diagnose this and correct it.

Merry Christmas to all Audi drivers

 

Anyone have any ideas?