I just recently got my car back from the Mini dealer after a serpentine belt came off while driving. They replaced the hydraulic tensioner for the serpentine belt. This was also supposed to fix the squeaky noise that the serpentine belt created off a cold start. They also replaced the belt again.

When I drove out of the service garage everything was fine, but when I started it again later that night I saw the following problems.

• "Oil Service" and "Inspection" light
• A DIFFERENT sounding noise that SEEMS to be coming from the serpentine belt.

Here is a link to a video that I made to document the noise issue.
Once I drive it for 1 minute or so the noise goes away.

SIDE NOTE: They also replaced the valve cover to fix an oil leak at the same appointment. I am taking it back to the dealer today.

Please ask me any questions. I will answer them to the best of my ability.

Thank you for taking the time to read this.

UPDATE: Literally an hour after I make this post my car broke down whilste driving to the dealer.

The serpentine is torn. Here are some pictures I captured: http://imgur.com/a/IDmEv

UPDATE 2:

There news coming in that there was an aftermarket oversized pully installed that I didn't know about. Apparently the belt and pully where rubbing against the tensioner. Causing it to tear off.

This problem becomes solved and, unfortunately, not very useful to you other mini owner because it is proprietary and the result of me not knowing what parts are installed on my car because I am not the original owner.

 

I had a squeal coming from the belt area, traced it to the idler pulley (the one that doesn't drive an accessory. A good trick to trace noises is to get a pipe/tube and put one end to your ear, then move the other end around the area you believe the noise to be coming from. You can easily identify which pulley is squealing if it is one.

But if the belt is torn, check the crank pulley alignment/bearing. It will tear belts if it isn't aligned properly or the bearings have to much play.

 

You should get a belt strap installed to save any future mishaps if belt snaps again. Gosh it must really suck not being able to work on your car. Hopefully the cost is not to bad.

 

The mechanic diagnosed that the aftermarket belt tensioner dampener was rubbing against the belt causing it to tear.

 

The mechanic at the MINI dealer who replaced the "hydraulic tensioner for the serpentine belt" you alluded to in the original post?

That's what is creating the loud clacking sound in your video?

 

No the after market part was something my Dad had put on the first time the belt came off that I didn't mention before.

There is also news coming in that there was an aftermarket oversized pully installed that I didn't know about. Apparently the belt and pully where rubbing against the tensioner. Causing it to tear off.