paulie04

Hi,


I have a 2008 a4 quattro 2.0t (b7) with a mystery of an A/C (air conditioning) problem. The problem is that when the car is idle (stopped or in park) and the A/C is on, with recirculation, high speed, low speed (no setting change makes a difference), after a couple minutes, I get no cold air. Only room temp air blows.

When the car is moving 15+ mph, I get cold air.

I had my local dealer assess as well as an independent mechanic. Here's what the experts did/found out:

- A/C system was recharged
- the vents inside the car are correctly blowing air
- the real culprit appears to be the Radiator fan... the one on the left (if looking top down from outside the hood) supposedly cools the engine and it moves as needed. However, the one on the right (the one that supposedly sucks air for the condenser) does not want to stay on. Every couple of minutes while A/C is on, you can see it try to start up, does one or two rotations then it stops.
- as such, the radiator fan control module (that sits at the front of the car) was replaced. Thinking was that the system was not telling/sending signal to the radiator fan to remain on to suck in air and cool inside.
- this did not help. cooling radiator fan continued to not work.
- one mechanic also swapped relays under the dash (one relay was known to work correctly) and the same issue persisted.

Anyone run into this problem? Have any other suggestions? Stuck here...

A4Audi4Fun

Are you able to get access to VCDS? the label file for the HVAC module shows a lot of measuring blocks that can be used to determine which components might or might not be working correctly; specifically there is one associated with the radiator fan in block 014

b7audisocal

Hi A4Audi4Fun

Did you ever find out what the problem was? I'm having a fan issue even though I changed out my fan module. I have a 2.0 B7 S-line.

David Ponce

I had this same problem, replaced the fan assembly with a new one from Rockauto, and worked just fine after. I also put a new fan control module just cause I was already there. Fixed it like new.

I changed the gas as well but sounds like you did that already, from what I'm told its always a good idea to do cause the gas stays clean and there lubricants in it that helps seals.