I haven't used my AC for a while until there was a heat wave in Southern California last week. Here's what I am hearing: There seems to be a whining type noise coming from the engine compartment when the AC is on. It is somewhat noticeable at low rpms, but it becomes VERY clear when the rpms reach over 3K. The car doesn't have to be moving or in gear for the noise to occur. At a 4K rpm point it is loud and I can make it disappear if I turn off the AC without letting the rpms go down.

I hope this makes sense. Can anyone help me determine where this noise is coming from? Is it a component of the AC system or its effect on some other engine part when running?

Thanks in advance for your time and help. My car is 03 MCS 99.3Kmiles.

 

If it is an rpm dependent whining sound, then that is the a/c compressor - in worsening condition. Mine has been like this for quite some time and has only recently become even louder. Still works fine though. My car sounds like Doc Brown's Delorean when I have my a/c on.

 

Have the same problem, Mini diagnosed it and said the exact same thing.

 

Nabeshin, you crack me up....

When I set the climate control no matter what the temp, doesn't the A/C come on anyways even for heat ? Because I thought most manufacturers did that to keep the seals from drying out ?

 

Thanks for the replies.
Yes, it's an RPM-dependent whining sound... An AC compressor replacement is in the cards then. It works fine at the moment (e.g., cools down quickly, etc). Just the noise that's a bit annoying, but I can live with that until it dies completely. Does that sound like a plan?

 

Who's the supplier/manufacturer of the A/C compressor?

 

So, if I let it take its course, how will it end? Will the A/C compressor just stop working or will it just start to blow warm air? If it fails, does it take anything else with it?

Lastly, does this noise have anything to do with my pulleys? I have a 15% SC pulley and the Crank pulley was replaced with an OEM, 05+ MINI crank pulley.

I asked around and it looks like this will cost me around $550 for a rebuilt or $750-800 for a new one.

 

Have you had the A/C checked? Mixed into the refrigerant is an oil. If there's not enough oil, it's like an engine running dry on oil. Maybe all it needs is to evacuate the refrigerant and charged with new refrigerant and oil.

 

Thanks for the suggestion. I'll have it checked for the refrigerant and oil soon.

 

I noticed on my car when the dsc light stays on and won't go off, and when the a/c is on it will blow hot and the check light comes on and says it is a clutch relay circut. I found out that i will blow the f3 fuse under the hood and if i keep the a/c blowing hot it will fry my dme (ecu). My local dealer cant figure out the problem and now they don't want to work on my car.