Air Condition Troubles

[kurdi]

Hi,

The air condition on my 1998 528i is not functioning properly. Sometimes it cools and some times it does not. I would like to diagnose and see if I can fix the problem before sending to the shop. So, any help is greatly appreicated.

Here are a couple of clues:

1. I hear "gurgling" or whirring noise after a few minutes of operation. Any idea which part is making that noise (compressor, condenser, etc.).

2. When I start the air con, I notice a smell akin the wiper washing fluid. Is that an indication of some major coolant issue?

3. Last Winter, I changed the heat resistor thingy (the thing with a dozen or so spikes) to fix my heating problem. Could that be related?

Thanks so much for your help.

[sp0rky]

There are two things that are highly likely. There are also other issues that may be going on, but I will only mention the highly likely ones right now.

1st - Since you hear a gurgling, I would suspect that the heater valves are staying partially open even when the heater is off, and then closing later, or just not fuctioning properly at all. That would cause the AC air to warm up since the heater core is in front of the evaporator. (I had this problem not long ago)

2nd - I would suspect the AC evaporator expansion valve - it is what opens and closes the evaporator, etc, etc. I had this problem too. Very annoying. Replacing this part requires having a shop evacuate the system, though - as it is illegal to vent any type of refrigerant into the atmoshpere.

Good luck finding out the problem

[kurdi]

Additional information:

The aircon works fine when I am on the highway. I am attributing this the speed. But, as soon as I exit and go slower, then the aircon stops cooling.

Thanks,