2003 Mini Cooper R50, approx 170k miles, owned since new and well maintained. My wife loves this car as it was a surprise present many years ago, hence the desire to keep it on the road. It's her daily driver and is still a blast to drive.

For the past several months however, the accessory belt has squealed at idle and pretty much anytime you turn the steering wheel, turn the AC on, even open a window, use the locks, or open the door. Yes, anything that needs a little extra voltage causes the belt to squeal. I've replaced the tensioner and belt with no improvement. The alternator charges and seems to spins fine, but everything points to a bad alternator. I'm planning to replace it this week, but thought I'd check here first to see if anyone experienced this before.

This is my first post, but I've gleaned a wealth of knowledge reading here over the years. Thanks all 🍻

 

I finally figured this out completely by chance. On every major parts web site, including Amazon, they show different size belts for first gen R50s. Using Dayco as an example (most brands use the last three numbers for the same belts), you'll find that 5060415 and 5060405 are both listed and said to be an exact fit for a Mini R50. 506415 is essentially an inch bigger than the 506405. I'm willing to bet that if your belt is squealing on your R50, you've got a belt that's too big.

 

Yep, its a 6PK-1033, some places have it wrong for MINIs and amazon is like the wild west on fitment. Glad you got it figured out.

https://www.ecstuning.com/Mini-2005-...e/Drive_Belts/