I replaced belt, idler pulley, tensioner pulley. The serpentine belt comes off when it rains. Please help!

I replaced belt, idler pulley, tensioner pulley. The serpentine belt comes off when it rains. Please help!


Enter the words SERPENTINE BELT in to the search forum on the right side of this forum and you will get many postes regarding this problem and fix.

Hate to tell you but when that happens (and those pulleys have been replaced) it means one of the others is freezing up and yanking the belt off. You should be able to see all the pulleys while they are turning. If there is any wobbling or side-to-side movement it indicates a bad bearing. If they all seem to be smooth and even, try turning on the a/c or turning the wheel while you're watching the belt/pulleys. If any of those pulleys has a bad bearing behind it the belt will jerk and be thrown off.

Thanks for the advice and I'll check it out.

And, you might want to take a good look at your motor/trans mounts. If any of the 3 is busted it will let your whole engine/tranny move enough to let the belt slip off the idler pulley.

And, you might want to take a good look at your motor/trans mounts. If any of the 3 is busted it will let your whole engine/tranny move enough to let the belt slip off the idler pulley.

What? There is absolutely NO correlation to the position of hte engine in it's mounts and the fact that the belt will go out of alignment if the negine shifts. There is no possible way this can happen like this.

What? There is absolutely NO correlation to the position of hte engine in it's mounts and the fact that the belt will go out of alignment if the negine shifts. There is no possible way this can happen like this.

You might not think so, but I've had it happen on two cars...my van and a Sable wagon. Anytime the engine shifts it can cause parts to misalign. I know all the pulleys are sitting on the front of the engine, and theoretically they all move at the same time, but it's not that simple. It takes very little to have a belt slip off a smooth pulley if something is tugging at it or misaligned.

All I suggested was to check them out. In fact, when these vans get to the mileage where pulleys and bearings are failing, the motor/trans mounts are not far behind if they have not already been replaced.

Knopp; your van is a '90? I thought I read '96. Amazing that it's still on the road at all.

Is the belt shield still in place?

If you're still having this problem, I found the solution. Dorman makes a shield that goes over your tensioner pulley. It totally solved the problem. I could drive the van through a puddle with no problems. I bought two of them because I had two vans. I only used one and I sold the other van before I installed it so I have a spare. I bought it from Rock Auto and it was about $11 or so. With shipping it cost me around $15. If you can't find it PM me and I can sell you mine at cost + shipping.