Just a while ago, every time I would do a tight turn or have the AC on my belt would do the most gut-wrenching squeal. So I replaced the belt, and it still continues. Then I replace the belt tensioner and the belt again and the squeeling stopped for MOST occurrences. But when I have the AC on AND do a tight turn, all that tension on the belt makes it squeel again. I all of this has happened within the course of about a month and a half so the most recent belt can't be the problem can it? I don't know what to do.


-I own a 2003 R50 Mini Cooper N/A with just shy of 35K miles.

 

Maybe an oil leak or cv boot grease getting on the belt? Noticed any leaks?

 

We're going to assume you have the correct tensioner and belt, so the last possibilities would be the things the belt rotates around.

Harmonic balancer. Do you smell burning rubber?
Tight turn squeal: could it be related to a heavy draw from the PS pump to alternator?
Could the idler pulley (does an R50 have one?) be borked?
Alternator and AC bearings could be gone too.

I'd say since it appears to be "load" based, that can be used to diagnose it (by a smarter person than I)


Sorry it's not a lot of help, but there's the options I could think of.

 

Verify that it is actually the belt making the noise.

What your describing is more like the clutch noise diag we see as you load the clutch with the low RPM.

Plus the P/S pump isn't driven by the belt so turning shouldn't affect the belt.

 

That's why I said "putting extra load on the alternator". It's not unreasonable to think that with these early PS pumps, they may be drawing too much, and if it's an original alternator, it could be on its way out. The "hard turn" condition is the strange part.