I just finished replacing the timing belt tonight on an '07 A4, and now the fan is running really high all the time. Any Suggestions?

 

Did you replace/lose coolant?

 

Yes I replaced the coolant.

 

Make sure there is no air in the coolent system. That can cause the car to run hot which would make your engine fan run more often. Did you replace the water pump when you did the timing belt?

 

Yea, I replaced the water pump as well. This afternoon it was running normal. Is it possible the air worked its way out? I just found this to bleed the system, is this what you would suggest?

To remove the air have your car turned OFF. Pull off the left heater core hose where (under the accordion cover) where the bleed hole will allow the air out but the end is still attached to the flange.
_Completely_ fill the coolant reservoir and keep it filled through the process otherwise coolant will not enter the crossover pipe. Unscrew the three screws that attach the coolant reservoir. Lift the reservoir in a way that the coolant can enter the metal crossover pipe through the small hose on the side of the reservoir and ensure the reservoir is higher then the bleed hole on the heater core hose. Eventually you will see constant stream of coolant come out of the bleed hose on the heater hose.
Reattach everything in reverse order and you should now have a bled cooling system.

 

It is possible that trapped air moved through the system and into the resevoir. That process should work although I haven't researched it myself on these cars. Luckly I haven't had to bleed my system.

 

Had same thing happen to me after T/B, W/P and thermostat replacement. Drove me crazy, the high speed fan just would not stop. Scanned it with VAG COM and performed reset, everything was immediately OK. This was almost a year ago. In my opinion, problem was caused with coolant going down the wiring and causing a short.