AirCon

[jonathanfenton]

Hello, just been on a 350 miles round trip to a funeral to find that the aircon is woeful at best. Was serviced at Audi 2 years and 15000 miles ago. It sits on the driveway for weeks at a time especially now with corona. Been told by friends it could be because it sits so long the seals have dried out and slowly leaks? Noticed after parked for a while and restart i could hear a loud hissing and bit of gurgling for around 30 seconds as everything fired up, went away as we started driving again.
Any opinions, dealers are shut and anyone open is just gonna try to re-gas it so would like to know any suggestions to check anything, I have a fully licensed VCDS.

[Alan02]

Best get a code read first. I`ve had a C6 and my C7 A6 get aircon faults and it was always the pressure sensor. Easy to change and no re-gas required. The noise you heard could be related... but equally, may not.

[Caino6]

Another suggestion could be if possible can you see what the pressure reading is with the vcds? If the pressure is low or no pressure at all then yes the gas may have leaked out, you will need to have a pressure check carried out with nitrogen to see where the gas is leaking out. It is actually illegal for garages to just carry out a regas without checking for leaks these days if the system is low or has no gas in system.

[jonathanfenton]

No codes stored related to hvac, checked live pressures and was showing 5bar which I checked against a table and for the ambient temp of 19°C was supposedly correct?

[Caino6]

Yes 5/6bar is about right. Can you hear the compressor cutting in and out when you turn the aircon on/off?

[jonathanfenton]

Yeah it all sounds like the clutch is working correctly. Fans spin up after a min or so of it running.

[Caino6]

If that’s the case, the pressure seems ok, and you can hear the compressor cutting in, then I’d say yes, regas the system. The regas machine will draw out any moisture in the system and refill with the correct quantity of gas, hopefully that should make it efficient again. Have you had any leaks or any of the system open to atmosphere in the past? For example any work carried out on the car that requires removal of an aircon component?

[jonathanfenton]

I’ve owned it 18 months and never had any part of it open, who knows in the past, full main dealer service history. Spoke to Audi UK who said the aircon was serviced 15/05/2018 so seems a little quick to need doing again.

Will wait for the madness to be over and get it done again and see if it stays working or if it leaks out again etc.

[Caino6]

The only other possibility I can think of is maybe the receiver/dryer needs changing. That’s the component that removes the moisture out of the system, and if it’s full then the moisture will not be able to be fully removed from the system over time, so the system won’t be as efficient and won’t produce cold air.

[jonathanfenton]

Isn’t there a drain out of that though?