Help! Shredded 4 serpentine belts in 100 miles.

[suspenceful]

I'm in desperate need of help. About 3 weeks ago I heard a faint squeaking noise that increased and decreased with RPMs. Car drove fine and it all looked good under the hood. 2 days later it got worse, so I checked under the hood again and saw this:



So, I ordered a new belt and tensioner and put them both on with the help of a friend. Did the oil filter housing gaskets at the same. Install went smoothly and the car was back on the road. Drove around for over an hour. Mix of city and highway, multiple WOT pulls. After I'm convinced the car is good, I head home. Two blocks away I hear a pop, squeak, and smell rubber. I pulled the car in the garage and see this near the alternator:



Belt tightly wrapped all around the alternator pulley. It also burned up the plastic pulleys on the brand new tensioner. I noticed some scoring on a black pipe near the power steering pulley. Wasn't sure if it was from shredded pieces spinning around and hitting it or what.




Took everything apart and noticed the alternator pulley was seized. When the actuator was locked, the pulley wouldn't spin either way. It should spin one way. So, we bought the Bosch tool to pull it off, along with a new alternator pulley, both idlers, and another belt and tensioner. Installed everything again and the car was good. Drove it around for two whole days and put many miles on it. Figured the alternator pulley solved the problem. Nope. Driving home tonight, I heard a noise and the battery light came on the dash. I knew what it was. Pulled over and saw the remaining belt fell off the pulleys. Shreds of belt were scattered around. Drove the rest of the way home and pulled the fan out.

Current situation:


The car has now eaten through 4 belts (factory belt + 3 more in the last 100 miles). I'm so frustrated. I have this procedure down to a science and am positive it isn't user/install error. I do not want to waste money bringing it into a dealership unless I have it. I've already spent way too much trying to fix this 3 times. All Continental belts and INA parts.

Each time the belt has shredded the car was coasting or at a steady speed. Never under acceleration or WOT. What next step should I take?

[Jcrewsn]

I think it may have some relation to worn out engine mounts. I had something similar happen to me and the dealer took care of it under warranty. Would have cost me $2200. Pretty sure they had to replace all engine mounts, belt and pulley. This issue was that the pulley and belt were smashing against the subframe at WOT. Good luck

[suspenceful]

Originally Posted by Jcrewsn

I think it may have some relation to worn out engine mounts. I had something similar happen to me and the dealer took care of it under warranty. Would have cost me $2200. Pretty sure they had to replace all engine mounts, belt and pulley. This issue was that the pulley and belt were smashing against the subframe at WOT. Good luck

What month and year was your 1er produced?

Every time the belt has shredded, I've either been while coasting or at a steady speed. Never when accelerating or going WOT.

[edisapimp]

http://www.1addicts.com/forums/showthread.php?t=1063860

[Silenus]

SI B 11 09 08
Engine July 2010
Technical Service

designates changes to this revision

SUBJECT
Alternator Drive Belt Broken

MODEL
E82, E88 (1 Series) with N54 engine up to 4/08


E90, E92, E93 (3 Series) with N54 engine up to 4/08 except xi models


Situation
The models listed above utilize a single serpentine drive belt for the power steering pump, alternator, and air conditioner compressor. During normal driving, the front engine mounts allow the engine to move slightly on the front axle carrier. However, under extreme conditions, such as driving at high rates of speed over curbs or speed bumps, the engine movement can result in the serpentine belt or power steering pump pulley contacting the front engine carrier. If this occurs, the belt and/or pump pulley could be damaged.

PROCEDURE
When diagnosing a complaint related to a broken drive belt or a drive belt which has come off the pulleys, it is important to carefully examine the power steering pump pulley for any signs of damage.

If there is no damage to the pulley, continue with normal troubleshooting.

If the pulley is chipped or cracked, then the pulley and the belt must be replaced.

In cases where the pulley has been damaged, the front axle carrier should be examined for any signs of contact in the area below the power steering pump pulley.

If the axle carrier has any sign of contact, then the carrier must be replaced. For E90, E92, and E93 vehicles produced up to 3/19/07 which require replacement of the front axle carrier, the left side engine support (P/N 22 11 6 760 317) must also be installed.


The following sections of the Repair Manual should be referenced, depending on the repair(s) which are to be performed:


Repair Instruction RA 32 41 100 "Removing and installing/replacing belt pulley on vane pump for power steering"

Repair Instruction RA 31 11 001 "Replacing front axle carrier"

Repair Instruction RA 22 11 110 "Replace left engine support arm (N54)"

PARTS INFORMATION
Part Number
Description
Quantity

11 28 7 568 247
Poly V Belt 7PK 1855
1

32 42 7 553 955
Power Steering Pump Pulley
1

31 11 6 785 639
Front Axle Carrier
1

E82 up to 4/08

E90, E92 up to 4/08

E93 up to 2/07

31 11 6 785 640
Front Axle Carrier
1

E88 up to 4/08

E93 up to 4/08

22 11 6 760 317*
Left Side Engine Support
1

E90, E92, E93 up to 3/19/07

07 14 7 199 279
Rivet
4

E93 up to 4/08

* For E90, E92, and E93 vehicles produced up to 3/19/07 which require replacement of the front axle carrier, P/N 22 11 6 760 317 must also be installed.

[suspenceful]

I've done plenty of reading and don't think my year/model is part of the affected cars. From my understanding, the only affected cars are anything with an N54 up to 04/2008 production date. I checked the clearance, and my PS pulley does not come in contact with the subframe.

[suspenceful]

UPDATE: I searched the forums for hours for reasons this might be happening. I noticed that a handful of people noted that the bolts holding their PS pump (not the pulley) on were either coming loose or missing all together. Obviously this will throw the belt out of alignment if a pulley isn't straight and true.

So, after tinkering around last night, I found the culprit. My PS pump was missing 1 bolt and the other 2 were loose. The pulley would shift if I grabbed and shook it. Going to tighten everything up with loctite and she should be good to go.

[Ultimateone]

Good luck, thats some unlucky bs

[tglazed]

Yup mine was missing 2/3 bolts. Took me a while to figure it out. Shredded two belts and replaced the idler pulleys twice cause it melted them when the belt shredded

[Dackelone]

Originally Posted by suspenceful

The car has now eaten through 4 belts (factory belt + 3 more in the last 100 miles). I'm so frustrated...

Each time the belt has shredded the car was coasting or at a steady speed. Never under acceleration or WOT. What next step should I take?

I see you posted your PS pump's bracket was missing some bolts. I hope that is your problem.

Also... some guys a few years ago... posted some threads where the front crankshaft pulley was damaged/bent. They damaged their pulleys from drag racing/hard launches/axle hopping. The engine would move around so much during a hard launch that the crankshaft would contact the front subframe - damaging it.

FYI... the Alternators on BMW's(since 2007 model year) only charge the battery when coasting or decell. This is part of the efficient dynamics. This might be part of your problem. ?