Alternator belt shredded to pieces

[Walmart Parking Lot]

Hey all, was doing a road trip with my buddy the past weekend. Had a great time. I did a ~60-140 pull (in Mexico) and I felt power loss. A couple minutes later, I got a "Charging malfunction" error. It was around 90+ degrees fahrenheit, I had the AC on, radar detector plugged in, and my phone charger plugged in. It was also a slightly uphill.

I opened the hood and saw my alternator (serpentine) belt completely shredded to pieces. Since I was in the middle of nowhere pretty much, I went to an Autozone and picked up a 55 inch, 6 ribbed belt. Our vehicles have the 55 inch, 8 ribbed belt.

I had to use the 6 ribbed belt until I was able to drive it around 350 miles back home.

I'll be getting the right OEM belt installed this week.

My question is, what do you think caused it? Wear and tear, premature failure, and/or too much stress?

Car info: 41k miles on Stage 2 ACN BM3 tune. I also have the Maximum PSI 4-pin crank hub and Vargus CBC installed.

Edit: Apparently when you put the belt back on, you're supposed to put it back on in the same direction. Not sure if the shop did that after they installed the crankhub. I called the shop up and asked them if they did and they said they did, but they still offered to install the new one for free. Great customer service.

[hC1001]

Its known to happen. check the idler pulley, i assume its okay if the new belt was working. How many miles are on the car? Hopefully some of the pieces didnt get sucked into the crank...
https://f80.bimmerpost.com/forums/sh....php?t=1623258
https://f80.bimmerpost.com/forums/sh....php?t=1652795
https://f80.bimmerpost.com/forums/sh....php?t=1146559

[Jbonly21]

Man that is the worst, my N55 x5 threw the belt and pulley a couple of months back. After replacing those parts, I noticed the car started leaking oil after every drive. After doing some investigation this is what I found.
If I were you I will just go ahead and replace the crank seal, or at least check. And why you are at it, might be a good time to add crank bolt capture.

[tom @ eas]

Happens on S55 also. Accessory belt shredded and was drawn into the crankcase past the front main seal. New VTT SplineLock Crank Hub and CBC installed to bulletproof while in the area.

We go into detail about it in this thread: https://f80.bimmerpost.com/forums/sh....php?t=1623258

[Walmart Parking Lot]

Originally Posted by hC1001

Its known to happen. check the idler pulley, i assume its okay if the new belt was working. How many miles are on the car? Hopefully some of the pieces didnt get sucked into the crank...
https://f80.bimmerpost.com/forums/sh....php?t=1623258
https://f80.bimmerpost.com/forums/sh....php?t=1652795
https://f80.bimmerpost.com/forums/sh....php?t=1146559

Thank you, I will take a look.

Originally Posted by Jbonly21

Man that is the worst, my N55 x5 threw the belt and pulley a couple of months back. After replacing those parts, I noticed the car started leaking oil after every drive. After doing some investigation this is what I found.
If I were you I will just go ahead and replace the crank seal, or at least check. And why you are at it, might be a good time to add crank bolt capture.

Originally Posted by tom @ eas

Happens on S55 also. Accessory belt shredded and was drawn into the crankcase past the front main seal. New VTT SplineLock Crank Hub and CBC installed to bulletproof while in the area.

We go into detail about it in this thread: https://f80.bimmerpost.com/forums/sh....php?t=1623258

Forgot to mention, I have the Maximum PSI 4-pin crankhub and the Vargus CBC installed. Does that mean I'm "bulletproof" in that area?

[tom @ eas]

Originally Posted by Walmart Parking Lot

Thank you, I will take a look.

Forgot to mention, I have the Maximum PSI 4-pin crankhub and the Vargus CBC installed. Does that mean I'm "bulletproof" in that area?

Belt can still get by, no matter what crank hub is present.

[Walmart Parking Lot]

Originally Posted by tom @ eas

Belt can still get by, no matter what crank hub is present.

Oh sorry misread it. You mean "bulletproof the area" as in preventing the crank hub issue

[tom @ eas]

Originally Posted by Walmart Parking Lot

What about VTT CBC?

Not related. A shredded belt is a result of premature failure (belt, tensioner/pulley) or poor maintenance.

[hC1001]

Originally Posted by Walmart Parking Lot

Thank you, I will take a look.





Forgot to mention, I have the Maximum PSI 4-pin crankhub and the Vargus CBC installed. Does that mean I'm "bulletproof" in that area?

Did the shop reuse the belt or replace after crankhub work? Repair manual says to mark the belt orientation and put it back in the same orientation otherwise there can be a belt failure. Wonder if that is what happened...

[Walmart Parking Lot]

Originally Posted by tom @ eas

Not related. A shredded belt is a result of premature failure (belt, tensioner/pulley) or poor maintenance.

Yes sorry I edited my post above. I misunderstood you

[Walmart Parking Lot]

Originally Posted by hC1001

Did the shop reuse the belt or replace after crankhub work? Repair manual says to mark the belt orientation and put it back in the same orientation otherwise there can be a belt failure. Wonder if that is what happened...

Good idea, contacting shop now

[Walmart Parking Lot]

Originally Posted by hC1001

Did the shop reuse the belt or replace after crankhub work? Repair manual says to mark the belt orientation and put it back in the same orientation otherwise there can be a belt failure. Wonder if that is what happened...

Thanks for mentioning that. Contacted shop and they said they did do it but will replace for free.