IknowHuhA6

Hi Guys,
I have not had much time to do my due diligence as I'm used to. So hoped maybe I could get some good leads and advice for now.

My AC started to fail a few weeks ago. It would not cool unless I hit high speed which made me think compressor.

Drove to Mexico few weeks ago and temps hit 120. OMG! had no AC at all. I recently had damage to the lower intercooler radiator so bypassed it with my auxiliary heat exchanger for those that have seen my previous posts on this experiment.

Anybody else experience failed AC? Maybe it's just simply a need to add more refrigerant but I"m new to Audi so wanted to ask before I make incorrect assumptions.

Thanks a bunch. = )

dc2002

You probably lost your coil that is by the radiator...slow leak...I forget if that is the condenser or evaporator...I think condenser is the one by the radiator and evaporator is in the dash...one that gets cold...


Buy a cheap recharge kit with a gauge and see if you have pressure...I suspect not

newmoon

2012s also had problems with a leaking pressure sensor, revised part number 4H0-959-126-A. Mine was replaced under warranty.

https://www.audiworld.com/forums/q5-...-98-a-2884814/

tenspeed

Adding more refrigerant is a good place to start. If it doesn't last long (a year or so), take it in to have the system checked for leaks. They suck all the refrigerant out and leave it with a vacuum. If the vacuum doesn't hold steady, they add a dye and nitrogen and look for leaks with a UV light.

After 5-6 years, you should replace the dryer while the system it empty.

dctech

Also check your electric fan fuses. I had one of the two go out and noticied the lack of cold air once the car was siting on a hot day for a few minutes. With both blown, I'd expect that it would seem like there is no AC at all if not at highway speeds.

Vag-com will show a code for the open circuit. I did not save the code, but it was obviously worded. So you can check that before you start try getting to the fuses.

Here is a thread with good pics as to where they are. Removing the crossmember requires a triplesquare socket which I had from my B5 days. Otherwise it is very straight foward to get to. Don't forget to disconnect the battery before changing as those circuits are directly connected and are live even when the ignition is off. WV dealers carry the fuses as does NAPA where I got mine for $2.80.

https://www.audiworld.com/forums/a6-...use-s-2903519/

morski

If you have lost your refrigerant then it will throw an error code in vcds

jpru2001

Lost a sensor in my 2012. $40 replacement at Indy. Unfortunately they had to recharge the system for another $140 or so.

Vodka G

I did check refrigerant pressure, usually that's the symptom with int cold/not cold air