a/c problem
 

I have a mint 96 328i which I love dearly. For the last several months, my car has made a fairly noisy grinding sound when the air conditioner is in use. Performance (temp, etc.) of the a/c was normal. This week, however, the cold air would stop sometimes when the compressor would engage and today, while the car was parked with the a/c on for roughly 15 minutes, the car came very close to overheating.

I've been leaning towards a broken a/c compressor clutch and would like some technical reinforcement. If it is the clutch, no one seems to stock the part (without the compressor) and I would like to know where to order one. I don't feel like ordering the entire clutch and compressor if I only need the clutch.

Many Thanks.

Have you checked the refrigerant level? This can affect clutch operation. However a grinding noise would not be the clutch, but the compressor itself. Can you describe some of the conditions under which it grinds?

I have not checked the refrigerant level. When the air conditioner is on there is always a grinding sound when the compressor is on. I'm assuming it's when the compressor kicks-in because the car looses a little bit of power everytime the noise begins. The noise is constant and never varies in pitch.

Hmm. I would check the R-134a level and possibly top up, and also add some oil charge as well.

I'll check the level Monday and let you know. Thanks.

Was there ever a time where the A/C was not used for an extensive period?

The car was rarely used in the first 2 years of its life - 2,500 miles. Since then 145,000 problem-free miles and the a/c has been used constantly (except a few cold months in winter). This is the first problem with the car.

have you checked the level yet?

I have not yet checked the level and may not get to it for a couple of days (big project came up). I will let you know the moment I do. Thanks.

Compressor, you can check the level and add oil but the moment those things start making noise, you can put them to rest. Once the noise begins, it's almost guaranteed that any and all refrigerant and oil you put in, will be gone within three days tops (under frequent driving). Save yourself some $$ as well by replacing the drier at the same time. I would be willing to bet if you put some dye into the system and checked for leaks, you would find the compressor leaking from the front.