Air con not working, but compressor is fine?

[Glowman]

Vehicle is a 2007 TFSI and the aircon heats fine but fails to cool the air at all.

I've had the system regassed (it was completely empty) and that didn't help. My mechanic has checked the compressor which is fine and there are no errors reported on the system. All the lights and buttons on the control unit function as they should. Still just ambient temperature air blowing.

I know I'm probably being optimistic that we will eventually get a hot summer And need aircon!

Next step will be to take the car into an electrical specialist. But I wondered if anyone might have some suggestions?

 

[Jooles]

I had a van regassed at ATS last year (Groupon special offer only £30!) and it lasted exactly a week so I took it back and they said that by law they have to do a pressure test on it before attempting to regas so something must have happened during that week although I had done nearly 900 miles. Do you know if yours was pressure tested first?

Sent from my SM-G930F using Tapatalk

 

[Mun802]

I know it doesn't help you with your issue but I have the exact same issue on mine. Was regarded yesterday, no faults logged but only blowing ambient air??

 

[SootySport]

There's a few pipes in the car that carry the refridgerant gas around the A/C system. There is also some special oil that lubricates moving parts and keeps the pipe seals supple to stop the refridgerant escaping and if the A/C has not been used for some weeks, months, years then the seals dry up and let the refridgerant gas escape.
These days garages use an automatic machine about the size of a small fridge to do a diagnosis on the state of your A/C and pipework. The old gas and oil are sucked out into the machine and weighed, then the correct amount of gas and oil, according the make and model car are pumped back into your A/C system. That's what's supposed to happen.
Your problem is the seals have dried out or there is a leak somewhere in the refridgerant pipework.
One way of finding the leak is introducing a dye into the pipework via the Aircon analysing machine. a few days later if there are leaks a UV torch will show where the gas is escaping from. Usually costs about £15 to have the dye pumped in.
Unfortunately you can't do any of this yourself due to the equiptment required, you need an A/C specialist and of course can work out expensive. It doesn't have to be a mega expensive Audi dealer to fix this, an independent Aircon specialist can do all this.
Another important part is the drier and if it has gotten wet you'll need one of those as well.

If you do manage have it all sorted and working, make sure the A/C is used regularly, even in winter turn it on for one journey a week to keep the seals nice and supple. Use or loose it as they say

 

[Daveyonthemove]

This is so true. I know so many people that don't touch the aircon because they think it's only there for hot days, but it can actually warm the car too.
I've seen at least one friend come to use the aircon in summer and find the bearings have siezed and they have no aircon or a big bill to fix it.
I leave mine on all year around.

 

[Mun802]

I'm with you on that Daveyonthemove but I've only had the car a couple of months and have inherited the issue.

 

[Daveyonthemove]

That's unfortunate.
You would be better finding a decent Aircon specialist rather than going to a dealer or the likes of Kwick Fit. They will probably diagnose the problem quickly and accurately rather than trying out a few things at your expense before locating the actual problem on a 2nd or 3rd visit.
Hope it's a cheap resolution, whatever the issue turns out to be.

 

[traindweller]

Not sure where you are in the UK? I have used, and can recommend this company for air con parts and particularly the installation and recharging service if they are near to you.
http://www.coolcaraircon.co.uk

A/C is really difficult and there are so many components that could be faulty including the various temp senders controlling the a/c operations.
The a/c specialist obviously know where they are so as said above, using them over Kwik Fit could save you money in the long run.
Might at least be worth a chat with them over the phone to see if any common issue with your model. I hope you get it sorted.

 

[Glowman]

That would certainly make sense as the previous owner had only done 3000 miles or less a year for the past 3 years.

I'll take it to a general aircon specialist and see what a leak rest shows.

 

[Glowman]

So a quick update after taking the car to an aircon and auto electrical specialist....

Apparently the usual failure on the compressors is for the internal shaft to break. That's not the case with this one, it's the valve on the back of the compressor. So end result is the same - new compressor needed.

The car is now booked in for the required work.