Literally 1,000 miles after installing a 15% reduction pulley & Dinan Stage III software (which cost me over $500 in parts/ labor), my tensioner mechanism failed.. Sounded like a worn out belt was slipping, so I sprayed some WD40 on the belt. The sound went away for 1 day. The next morning, the sound was amplified 2x, but would normally go away when the engine got to normal op. temp. Slowly but surely, as the days went on, the sound go progressively worse until little kids and gardeners in beat up pickup trucks were starring at my Mini's noise issues. My pride was definitely being tested. It was time to fix it.

Took it in to get repaired at www.avusautosport.com in Glendale, CA (i strongly recommend them), and it turned out to be the ENTIRE idler tensioner pulley mechanism. The bearing on the pulley were practiclly seized, rusted and squeeling horribly! This is not a small job, and requires a special BMW tool to install. I would not recommend anyone do this on their own.

Perhaps it was my 15% reduction pulley that sped up the failure. If I didn't like this car this issue would have pushed me to sell it, but it is probably my most favorite car I've ever owned. Every penny in maintenance is worth it!

Anyway, sorry for my rant. I am curious to know if this is a common problem?

 

With a little bit of research you would have found that the part is about $125 and you can replace it yourself if you have access the the tensioner tool (about $100).

 

No interested in hoisting my engine out of the car.. it was worth the 400 bucks to have it replaced

 

When I had my 15% pulley done, I had them replace the tensioner and idler while they were in there. I should have had them replace the leaky motor mount too, but I figured that's pretty easy to get to when I'm ready. I've had a tensioner fail before and it's ugly.

 

you dont have to hoist the engine, i installed mine with a jack and 2 jack stands. some even say the do it without lifting the engine at all. it took me about 4 hours, but i was also installing the solid engine bushings (which took most of the time). its really not that hard

 

I helped a buddy do his and he didn't even have to jack up the engine, just got it from the wheel well.

The stock tensioners do go bad, most are damper failures tho. Best investment is to get a tensioner stop from Detoit Tuned, Alta, or Minspeed.

 

The almost-new OEM belt on our 2002 200k+ would scream and sequel when starting the car, but stop after awhile, allowing me to procrastinate for weeks. Eventually,though, it got embarrassing enough that I had to bite the bullet and see what the bad news was. Jacked the car, pulled the wheel and wheel well, and pulled off the belt. No big deal so far. Sure enough, the tensioner wasn't doing it's job. Took one look at it and thought "this is going to get ugly." Thought for sure I'd have to pull the motor. But the pulley was fine, bearings were tight, it was just seized at the pivot. I managed to spray a little WD-40 at the hinge point, exercised the mechanism with a 3/8 drive breaker bar (tight fit, but works fine if you have one skinney enough; this is what you have to do to de-tension the belt for removal) and all was well with the universe again. Total cost: $0 and about 30 minutes. Made sense in hindsight, the tensioner just doesn't move much in normal operation, so it's bound to get a little stiff after 7 years.

 

I agree with BigShot. Get a tensioner stop. If something were to happen to your belt, it will keep you from destroying your pulley.

 

Great news. A better alternative to the WD-40 is a product called Break-Free. It is used by the hunters as a gun lube. Very nice product with no kerosene.....!