curtisaudi

I have a 1998 audi cabriolet, and my air is not working, I just had it recharged at the dealership, and it was working fine, but a couple of days later, it just blows hot air, the compressor comes on when I turn the air on but no cool air. Could it be a leak?

Rusty Spokes

Maybe..however the A/C system has a high pressure and low pressure switch in the system and if the refrigerant is low..then usually the compressor will not kick on.

All that said..you may have a leak and there is enough 134a refrigerant in the system to kick the compressor on..but not enough to cool the cabin.

Do the radiator fans come on when you depress the A/C button? At the same time as the compressor kicking in? They need to run to help the condenser in front of the radiator..if the fans are not working with the A/C on then your A/C will not cool very well.

If the fans are running at the same time..I would visit the shop and ask them to investigate..the A/C system is actually very simple and the shop can check for leaks and pressures (at least the high side) and see what they say.

If they suspect a leak...Do have them check that schrader valve on the high side port carefully to be sure it is not leaking..they will leak after servicing the A/C from time to time. Easy to check.

curtisaudi

the fans do com on when I depress the aircon button, thanks for the info, I am going to have the system checked for leaks

EuroGuy9622

If it was recharged by a dealership that means they are EPA compliant and should have put dye in a system that needed to be recharged.
On my Audi, I talked to my shop (not a dealer) about AC service. They explained the EPA compliance and that it would be rather expensive for them to do an evac+ recharge just to find out after I have a leak. They recommended I charge it up myself first and put a dye can in it. So I did. One tall can of AC Pro that comes with 'leak stopper' (just seal swellers) and the air remained ice cold. Way better than my Dodge pick-up ever was, and that had a condenser 3 times the size.
Not everyone gets that lucky with the DIY leak-stopper stuff. I usually don't; my intention was to have the shop find the leak after, or find it myself and have it repaired. In this rare case it was not needed.
One other note on leak-stopper- don't bother with the kind that says it seals metal. This will effectively seal off the orifice tube. I've seen it done....


An easy way to tell if you've lost a bunch of refrigerant since the charge-
Check how long the compressor clutch is kicking on for. If it lost a bunch of freon, it will only cycle for a couple of seconds (and on an older car usually pull on the motor quite a bit) A compressor running a full charge will be seemingly be non-stop engaged at idle, perhaps taking a quick pause at long intervals.

joegolden481

I just picked up a 1995 A6 that seems to have similar issues. The system blows cool ish air. Not cold. The fans run and the compressor runs at all times when the a/c is switched on. I have some freon with oil additive and a hose with the built in gauge. I just can't find the low side! I found one port behind the front grill mounted to the condenser but I am not sure if that is the right one. Any clues guys? Thanks

EuroGuy9622

Joe,
There is a list of things that could be at play here (not a favorable answer, I know)
IF in fact you are simply low on freon, please check your pressure before dumping a bunch in, Too much and you'll have a worse time.
Your low pressure port is either on or near the Dryer/accumulator. This is a canister in the AC system that filters out moisture. If it's not right on the Dryer can, follow a line from it and you should find the Low port.

If your compressor is running and your system pressure ends up normal yet you're not ice cold, you may have junk all over your evap core, or filter if a '95 has a cabin air filter. Also you could need a new Dryer. As stated, it is a filter and eventually changing them does help. This would require the system be evacuated.