My 02 2.5 X-Type with 75k miles has a noisy a/c compressor. It's noisy at idle when the a/c is off. I think problem is with the end of the compressor that's supposed to turn when a/c is on and not turn when a/c is off. When I turn a/c on, the noise stops.

When a/c is off, it looks like it's not completely disconnecting from the compressor - it turns a little and makes a squeeking type noise when it turns. I know it does this at idle, but don't know if it does it when revving up.

Any ideas? An a/c shop said maybe the compressor doesn't get enough electricity at idle to completely disengage the clutch, but didn't want to touch it because it was a jag.

I added a/c oil and topped off the freon, but it made no difference.

Thanks for any suggestions.