Shredded serpentine belt

[8cam]

On my way to meet some friends this afternoon and I had my very first breakdown. My own damn fault. I had noticed a squeal when I turned on the a/c for the last couple days, but didn't think much of it because it quieted down right away, figured I'd get to it this weekend. Well halfway to where I was going, and it didn't squeal, it screamed, even with the a/c off. I pulled into a gas station, popped the hood, and was greeted by fragments of belt everywhere and about 2 strands still on the pulleys.

Needless to say I didn't make it to the meetup. I Uber'd to the nearby Napa, got a new belt, and did a roadside replacement. All is well now, all pulleys are turning perfectly with no discernable wobble, and all belt-driven stuff is working perfectly.

I've always thought the tensioner vibrated more than it should, but it was rebuilt by Marc 20k miles ago and everything has been fine. But 20k on the belt and a catastrophic failure, luckily in a place where it was easy to pull over and take care of the problem. But what in the world could have caused it?

[We Gone]

Great job

At least you were able to fix and run, I always carry an extra belt and a few of the hard to find hoses in one of the storage boxes behind the seat and a few tools.

[Paul Workman]

Mark, I had exactly the same thing happen once. Turned out to be the AC compressor locked up; momentarily at first and then full lockup. Of course the belt squealed and some melting of rubber occured. Turning off the AC and disconnecting the connector to the clutch allowed me to get to where I could deal with the compressor.

I'm thinking AC compressor....

[8cam]

Paul I think you may be right. I've been a little suspicious of my compressor for a long time. It's always seemed to drag on the engine more than I think it should, and this squeal only occurred when I turned on the a/c, until it didn't. Of course with the new belt it worked perfectly and the a/c was great all the way home.

Before I installed the belt I checked all the pulleys and the a/c pulley turned freely, no issues. Maybe it's the clutch?

[Paul Workman]

Originally Posted by 8cam

Paul I think you may be right. I've been a little suspicious of my compressor for a long time. It's always seemed to drag on the engine more than I think it should, and this squeal only occurred when I turned on the a/c, until it didn't. Of course with the new belt it worked perfectly and the a/c was great all the way home.

Before I installed the belt I checked all the pulleys and the a/c pulley turned freely, no issues. Maybe it's the clutch?

The clutch itself? No. But, for various reasons, the compressor can hydrolock(?) maybe -. That would be a question for a HVAC person.

[A26B]

FYI. Like a number of other LT5 parts, the LT1/4 AC compressor clutch is often represented as being correct for the LT5. In fact, it is not the same. The pulley is different, resulting in misalignment of the belt.... & ultimately belt failure.

As far as I know, the correct Clutch/Pulley assembly is not available separately from the compressor. Only Denso has the correct Clutch/Pulley and it is sold only with a new compressor.

[mike100]

I kind of mentioned it in the other thread, but take a tool to the tensioner and see if it 'pops' into a tighter position if you push and pull it beyond its position at rest. Just to make sure the tensioner movement isn't a problem.

[8cam]

I'm relatively certain my compressor is original, given the history of my car, but you never know. How can I tell if my clutch/pulley is the right one? 20k miles on a belt shouldn't be a problem, at least it shouldn't result in a failure like mine.

The tensioner was rebuilt my Marc Haibeck, also 20k miles ago, and it feels smooth and strong. I can pull it back by hand with a lot of effort, or smoothly with a breaker bar, no pops or hitches. It does vibrate quite a bit, but a number of folks have looked at it and said it was normal.