You are currently viewing our forum as a guest, which gives you limited access to view most discussions and access our other features. By joining our community, at no cost, you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is free, fast and simple, so please join our community today!
Over the last couple of weeks I've heard some noise..... intermittent, squeel, all signs pointed to failing belt tensioner.
Surprise! Not the tensioner. The Alta 15% reduction pulley (been on for about 10K miles) was slipping on the shaft. Brought the car to the dealer for a new belt tensioner, and to fix problem related to code P1688 . When the mechanic took the belt off, the supercharger pulley tried to fall off the shaft!
12/1000 of an inch of steel worn off the shaft. Even the new updated Alta pulley would be questionable trying to grab a shaft with this much wear. So the answer is a new (take off part from a JCW upgraded S) supercharger with stock pulley still installed.
The strange thing is that I was VERY careful when I installed the pulley..... used thread lock on the bolts, bought a new torque wrench to check torque. When the pulley was removed from the shaft, the 4 locking bolts were still tight.
The good news is:
1) my bypass valve doesn't need replacement (As suspected by P1688)
2) the dealer wants $1800 for a new SC..... I'm getting the take off for much less price.
LET THIS BE A WARNING TO ANYBODY WHO HEARS AN "UNUSUAL SOUND". My warnings were very mild.... infact, I heard a faint squeel one day, then not again for a couple of weeks. I took my time trying to diagnose the problem. BAD MOVE.
My trouble shooting was flawed by some "known issues" such as squeeling belt tensioner, and sticking bypass valve (p1688)...... these two issues caused me to go blind to the real problem which I should have seen long before it became fatal.
Good luck to you all
Donald
P.S. Thanks to Waylen, MiniGuru for all of his advice! He was ready to go out of his way to help me get a supercharger before I located one locally. He is a big help to the Mini Community and we should be glad to have him here.
Sorry about the supercharger, Donald, but thanks so much for sharing your story. Way is a great guy! 
