air con has died

[s2avant95M]

on the way back from goodwood yesterday my air con stopped working suddenly. the light stays on but no cold air...
when i press the switch this morning it causes the car to stall !! if i keep the revs up then its ok, but theres still no cold air.

any ideas? i guess it needs regassing as its not been as good as when i first got the car.

[dan_b]

I wonder, does this sound like the clutch on the compressor might be causing problems? If that's not driving properly, could that stall the engine?

When you switch the AC on does the fan come on? Do the revs go up a bit at tick over? Can you hear/ feel the compressor coming on and going off again?

[s2avant95M]

dan, i'm gonna go outside and double check what comes on when i press the button, i think the fan comes on but ill double check.

[scillyisles]

When you switch the air cond on when idling you should notice the compressor engaging by the revs dropping slightly before the engine revs rise again. You should also be able to hear the compressor working - from the sudden nature of your failure it sounds like your compressor is'nt engaging or working for one reason or another.

[audiman]

It could be a number of things. If it made the car stall, then that could mean either the compressor is working very hard (ie blockage in the system) or the thing has no oil in the system and is trying to sieze up. This could have happened if the system has had a leak and regassed at some point without adding some oil.

You say it suddenly happened, it could be a leak. The system will not engage the clutch if the gas pressure in the system drops, due to leakage etc.

Needs to go to an AC specialist, and the car checked out, ie pressures on the high and low sides of the AC system.

[s2avant95M]

It could be a number of things. If it made the car stall, then that could mean either the compressor is working very hard (ie blockage in the system) or the thing has no oil in the system and is trying to sieze up. This could have happened if the system has had a leak and regassed at some point without adding some oil.

You say it suddenly happened, it could be a leak. The system will not engage the clutch if the gas pressure in the system drops, due to leakage etc.

Needs to go to an AC specialist, and the car checked out, ie pressures on the high and low sides of the AC system.

Tom, thanks for the advice. Luckily there is an A/C "specialist" about half a click away from my house so i will be taking it on Friday afternoon armed with this information.

[s2avant95M]

ok, help please!!!

took the S2 to the local a/c specialist and he had a look and found out theres no gas, so then after further investigation says he cannot re-gas the system because one of the valves is the older R12 type and the other one is the newer R134a type. is this correct? he says i might need to get the system converted at great expense.

i guess it might be similar problem to this thread?
http://www.s2forum.com/forum/showthread.php?t=9754

[Bibby]

I may be able to help.

I had my avant regassed the other week but it had to be gassed it via the high pressure side (adaptor near the condenser - R134a) as the adaptor on the low pressure side was unrecogniseable.

The low pressure adaptor is indeed under the bumper on the left (as you look at the car) by the compressor, but you can charge the system via the high pressure side. It just takes a little while.

Oh, and I paid £55 cash for my recharge.

[audiman]

Yeah, BTDT on 2 S2/RS2's. The high pressure port is the only one there. The low pressure port is on the compressor, but not the right size. Audi chaged gasses from R12 to R134a in about late 1992. The later cars can be gassed by using just the high pressure side. You need to vacuum the system for a while so that it will pull the gas in. No big deal. Sounds like they arent all that specialist!! I have never seen an M reg car running on R12!! We charge £60+vat at the moment, this has gone up due to the gas nearly tripling in price this year to nearly £150 per bottle.

I would find another AC repair dude. Im sure there are a good few in the yellow pages.

[s2avant95M]

thanks for the replies...that has put my mind at rest. i will search the yellow pages tomorrow armed with this information. he did worry me by saying i would need a new compresser etc etc....

[dan_b]

You'll want to put some leak detection fluid in there too to try and find where all your gas has gone. mine all leaked out through the compressor...

[horvathg]

Mine has similar simptoms. Its not necessary to replace the compressor if there is a specialist who can replace the stuffing box (packing box) section which is where it leaks most often. Especially if you do not use it for longer period. What I have found was that no non-audi specialists had the adapter plug to connect onto the compressor valve.

[kninio]

about this tread today i tried to turn on my ac and while i am driving i head such sound raise up with rave from the compressor , what could it be? some body add gaz with out oil? causing this voice from the compressor?

[Paul S2 Coupe]

For what it's worth, my A/C was leaking through the valve on the compressor and was discovered when they put the vacuum on the system. The spring on the valve was ******ed so it was only the gas pressure in the system that was holding it closed. The garage also could not identify the connection on the compressor but they removed the valve, and cut a new thread on the adaptor and screwed and sealed a proper R134a low pressure adaptor onto it with a new valve. My question is can anyone definately confirm that this IS the LOW pressure valve? Because the garage had never seen that connection or thread before, they advised me not to use the DIY recharge kit that I had purchased incase the cans blew up in my face as they could not confirm this was the low pressure valve.

If it is the low pressure valve, perhaps the way to go is to cut a 7/16 R12 thread and screw on the correct R134a low pressure adaptor which would make life easier in the future (and cheaper).

Cheers,
Paul

[s2avant95M]

i think this is the whole problem, the a/c guy did not recognise the low pressure valve on my car and so assumed it had been played around with in the past and did not want to touch it!!