A6 1.8t air con blowing warm when stationary, cold when moving

[morepower]

Hi, I have a 2002 A6 1.8T avant and the aircon is blowing cold when the car is moving and heats up when i slow down or stop.

The air con gas pressure was also very high so I was advised to get it regassed -it was done 2 years ago so i thought it was time to get it done.

The air con is still the same after ther regass so I went to see an air con specialist
He stated over the phone it could be the pressure sensor or the cooling fan that is at fault- on going to see the air con spec' he quickly checked the fans and said the viscous fan was at fault but then also said the electrical fan could be faulty but would need checking.

1) I would like to know if anybody else has had the same problem with there air con system and what corrected it?
2) I've never seen the electrical fan turn on - when should it turn on?
3) if the viscous fan is faulty (but still turning) could this cause the above?
4) Last of all where is the air con pressure sensor/switch located?


Thanks for reading

 

[mwarrey]

Hi, I have a 2002 A6 1.8T avant and the aircon is blowing cold when the car is moving and heats up when i slow down or stop.

The air con gas pressure was also very high so I was advised to get it regassed -it was done 2 years ago so i thought it was time to get it done.

The air con is still the same after ther regass so I went to see an air con specialist
He stated over the phone it could be the pressure sensor or the cooling fan that is at fault- on going to see the air con spec' he quickly checked the fans and said the viscous fan was at fault but then also said the electrical fan could be faulty but would need checking.

1) I would like to know if anybody else has had the same problem with there air con system and what corrected it?
2) I've never seen the electrical fan turn on - when should it turn on?
3) if the viscous fan is faulty (but still turning) could this cause the above?
4) Last of all where is the air con pressure sensor/switch located?





Thanks for reading

Hi, I had the same problem with mine, its the secondary fan (smaller one) that is probably at fault. You can check this yourself, basically when your aircon is on this should also be on. Its a very common failure on many VAG cars.

I have a document I can send you on how I diagnosed mine if you like?

 

[TYphoon GB]

Just re-read this...

Trust it wasn't a garage that advised you to get a recharge.....without connecting the easy 'dot to dot' of high pressure and no fan!! My how the chemical companies love 'experts'!

mwarrey notes are excellent on the fan fix! Just using them on a BMW and they worked on a TT.

As to the questions...

1) I would like to know if anybody else has had the same problem with there air con system and what corrected it?
You have that now
2) I've never seen the electrical fan turn on - when should it turn on?
All the time the air con is on ...there are a few versions that turn off under acceleration and some that will also switch in/out on temperature but if you need A/C then you need the fan.
3) if the viscous fan is faulty (but still turning) could this cause the above?
No connection to the A/C but if its not working your engine is cooking!
4) Last of all where is the air con pressure sensor/switch located?
Looking from the front of the vehicle its on the left hand side at the bottom of the condenser (front finned heat exchanger in front of the radiator).



Its on a schrader valve so can be screwed off and replaced without losing the refrigerant.



On my 2.5 but should be similar....