I have a 2002 R53, manufactured in Nov 2002. 78k.. Known problems: PS fan isn't working, PS pump is. Stage 1 fan is not working and AC is out.

In the past few weeks, I noticed a high pitched whine even at low RPM's, like when I back out of a parking spot, and when driving, the whine is still there, just higher pitched, but a little more faint. It's also accompanied by an even fainter whistle, almost like two pieces of metal are running against each other, although very smoothly. When I drop it in neutral, say at 40 mph, the noises disappear. I'm guessing it's a belt, but not sure which one... any ideas?

Thanks!

 

Try checking your IC boots for cracks and etc.

 

For reference... here's a video I made today..

 

I had the idler pulley (lowest pulley that isn't hooked to something) go out. Made very similar noises. The Stealership T/S it initially down the the alternator failing. Replaced that by myself (sucked) and the noise was still present. Anyway the use a stethascope to find what it is before you go crazy replacing things. Parts and labor costs are very expensive. You have to take alot of things apart to do much on the Mini. BTW if it is the idler you don't have to take the bumper/front end apart to repair. It can be accessed through the passenger side inner fender.

 

Yea, turns out it was the idler pulley and tensioner, both had bearings that were totally worn. I ended up going to Hubbard Woods, where Rich from NAM suggested; seems like they did a pretty solid job, i ended up paying about $600 total, a little more than I had wanted to; but i don't have a warm garage to do any work in =(

 

Just went through something similar and had a few details to add in case you're having the same problem. Mine would whine and then ring or whistle on and off at >2,000 rpm. My 2005 MCS has 118,000 miles.
I bought a cheap mechanic's stethoscope, $4 at Harbor Freight. It seemed olike the noise was loudest from the tensioner, and lots of other posts say that these are failure prone. I also got worried about having the tensioner pulley seize and/or belt break causing the tensioner/crank collision. So, I decided to replace the tensioner. What I learned:
- OEM tensioner is Gates part# 38404, $88 at RockAuto.com, $121 at O'Reilly, $160 at Dealer. I am pretty sure it actually is the OEM as the name on the casting arm is the same and the Gates box says "Made in Germany". I got the O'Reilly one as I wanted it ASAP. The instructions in the box are good and give the torque values.
- I also bought the Detroit Tuned tensioner stop, which is easy to install on the tensioner before hand.
- As a safety measure, you can stick a 1 x 2 or 1 x 4 board beside the pivot point of the special tensioner tool; it's easy to accidentally move right and pop the tool off if you hit the aluminum intake.
- I took the inner fender liner off. Not a big deal, just lots of fasteners, but worthwhile for ease of access.
- Slide the vacuum solenoid off - not worth hitting it or breaking it and it's easy enough to get off.
- You will need to remove the pass. side motor mount as well or you won't be able to get the tensioner out. Jack up the engine up a little first to remove mount, then and inch or two, then get the tensioner vertical and pull it out in front of the supercharger pulley.
- The big bolt heads on the tensioner are 16mm but 5/8 works fine
- Ratcheting box end wrenches are helpful.
- The guy I borrowed the special tool from said that when he added the tensioner stop, one of the bolts backed out, possibly due to the tensioner stop, so although it doesn't say anywhere that you should, I put loctite on all of the bolts.
- I have the red hardback Haynes Manual and it does not appear to say anything about tensioner replacement or idler pulley replacement, at least I couldn't find it.

So, before putting the fender back on, I fired up the car and ... ...the noise was still there #$%!. At least now with the inner fender off it was easy to put the stethoscope on the idler pulley bolt and it seemed clearer that the idler pulley was the problem.
So, I left it that way and priced idler pulleys - Gates #36168, made in Germany - Rockauto $26 and O'Reilly $40, went to O'Reilly again. The idler pulley is pretty easy, just need a 3/8 universal joint to make it easier. Now, no more noise...
Checking the bad idler pulley, there was definitely a little bit of play in the pulley.

So, if I was doing this again, before replacing anything:
- I would pull the inner fender to give access to everything, and then use the stethoscope.
- Remove the belt and check the pulleys for any play or movement - any movement means it's bad or going bad. You may have to yank on it hard a few times.
- Both items appear from the forums to be failure prone - if you're replacing the tensioner, I would just buy idler pulley as well - for only $26 it's worth it and there is minimal additional labor.
- I would have waited a while longer and gone for RockAuto if I had the time.
- One of the posts said a mechanic charged $600; now I feel much better since this isn't that difficult, saves a bunch of money, even using the OEM parts.
- Thanks go to karlh of HMMS for the loan of the belt tensioning tool.