Serpentine Belt Keeps Failing

My daughter’s 2 yr. old Toyota Corolla (S) is on it’s 3rd serpentine belt in 43,000 miles. She had it changed, yesterday, and the mechanic said the one he replaced was good quality but had numerous cracks. He checked all of the pulleys and tentioner, and found nothing wrong. The mechanic suggested the dealership collision center might have used something to clean the engine compartment when she recently had her car repaired. However, the repair was only the rear bumper/spoiler and the dealership denies they would have cleaned the engine compartment. I’ve changed a few serpentines (so much easier than old multiple belts) and never seen two wear out in 43k miles. Any ideas?

Even though the mechanic claims to have checked the pulleys and tensioner, I would strongly suspect that a pulley is out of its proper alignment.


Duh, THANKS. I should have thought of that in the 1st place. She had rear-ended a pickup truck’s trailer hitch a year ago (not really her fault but another story). I’ll have her have a qualified mechanic check the alignment. Thanks again!

Have the mechanic check the entire group on the engine including the alternator, PS pump and AC pump. If any of these has a bearing that seizes periodically it will tear up the serpentine belt quickly.

You’ve gotten the two possibilities, a pulley out of alignment and a bearing binding on one of the components. The best way to check the components is to remove the serpentine belt and check by hand for excess drag when turning as well as lateral and axial play of the pulley.

Be sure you ask the shop to check for both alignment and for a failing bearing.

Cracks on the inside ribs of a serpentine belt is normal. The serpentine belt not only drives the ribbed pulleys for the various components, but it also rotates around various idler and tensioner pulleys. This inverts the belt where the ribs are now facing outward of the pulley causing them to stretch and crack.

If the ribs inside the belt start chunking out or if the belt starts making noise, replace the belt.


Tester, and all who have given your advise, Thank you. The two replaced belts were making high pitched whining and/or clicking (in neutral, rev engine and frequency increased). The car is going in for a 45k service, shortly, to the Dealership. My daughter will make sure they check all pulleys, idlers, and tensioner for alignment, play, etc. There is obviously something out of alignment, warn bearing, or something wrong there. If you like, I will get back to all when the problem is found. Thanks again, Tom

I’ll bet that whining and clicking is a failing component that is also the source of the recurrent belt failures.