I have an 02 CooperS.
Car has 130,000kms (78K Miles)
15% pulley was installed about 40,000 ago. (24K miles)

I am getting a whiney squealy sound coming from the belt system that the supercharger is part of.

At first, i thought it may be the AC Clutch, but turning AC on and off doesnt seem to change the sound at all. It is almost always present, although less pronounced under load.

Any ideas what the sound could be?

 

spray the belt with some kind of lube.(wd40) and see if the noise goes away, if it does you need a new belt. if it doesn't use a stetoscope to pinpoint where the noise is coming from.

good luck!

 

fantastic idea joey. I tried that this morning, just after I posted.

As soon as the WD40 hit the belt, it shut right up.

Gonna order a new belt this week. Now to decide, regular CooperS belt, or the JCW belt. Im guessing JCW would be the better choice for my 15% pullied car

 

yeah the regular belt will not fit. which belt do you have there right now?
whichever one you have order that one.

 

Not true. The stock MCS belt will work fine with 15% SC Pulley.

 

Regular belt will most certainly fit (it does on mine). I have heard that the standard belt with a 15% pulley is good for ~40K (so your squeal is not unexpected).

 

I have the origional belt on the car right now (all 130K kms worth of it).

Im not surprised in needing a new one.

Even though the stock belt for the car seemed to work fine, is it recommended to change to the JCW belt seeing as its designed for a smaller pulley? Or just replace with what i have?

 

Here is a Goodyear #4060537 that is a little smaller than OE. I'm using this belt with an M7-16. The tension looks the same as stock with a stock belt & pulley using a tension gauge. These belts are easy to find at your local auto parts, cost $16 - $20 ( US ).