Serpentine belt squeak

Hello, I do most of my own work on my cars since I was a teen. However a repar I did 6 months ago is irritating me. I replaced my serpentine belt. And now is witer in Chicago, and if it’s wet out or the car is just starting and I turn the heat on it squeaks for a minute.

When I changed it I just broke my alternator loose to release the belt and maybe I was foolish. But after I installed the new belt I just took a pry bar to make the alternator tight and tightened it back.

Should I just do another new belt? Could I have messed it up by not going the the belt tensioner pully. Or maybe it’s just to tight?

Any advice is appreciated, I do most of my own work cause money is tight. Thank you lilly

I am not familiar with your vehicle but, most likely your tensioner needs to be replaced. a belt squeaks when it is slipping. so, your tensioner might be faulty and not putting enough tension on the belt.
I would change the tensioner and idler pulley too. If the belt just started squeaking, you might be able to reuse it. if it has been squeaking for a while, I would replace it too.
I am 63 and my dad gave me advice when I was a kid that I still abide by today.
" If you are going to do a job, do it right or do not do it at all"


Have you loosened the alternator, re-tensioned the belt and then tightened things up again? Belts do stretch out a bit after use.


Normally you don’t have an alternator that can be adjusted and a tensioner too. Just one or the other. So if it has a tensioner, probably time to replace that.


No experience w/you car, but I don’t think that’s the typical method when installing a replacement serpentine belt. I expect the belt tension is supposed to be set by the car’s tensioner gadget, not by prying on the alternator. Those tensioners get a lot of abuse as you drive the car, so I expect you’ll probably going to have to replace it to eliminate the squeak.

fyi, I have an older than yours Corolla, had that exact symptom a few years ago. My car doesn’t use a serpentine belt to drive the alternator, just a simple accessory belt. I was able to eliminate the squeak by doing what you did, adjusting the alternator position to tighten the belt. I didn’t use a steel pry bar though. Instead used an old broomstick, thinking the wood would be more forgiving wouldn’t likely accidentally damage the alternator’s casing. That method worked pretty good.

Tighten the belt, this is a known problem and Toyota increased the belt tension specification;

MC-10132608-9999.pdf (

BTW, you did use the correct belt tightening method.

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Interesting Toyota chose that method rather than a tensioner.
Haven’t seen a V belt in many years.

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Yes you have, now they just have multiple “V’s” or maybe they are “W’s” :grin:


You dad was better than mine, he wanted the girls and guys to do our own work. But was more figure it out yourself after you watch me once lol. But I learned thank you

Thank you this helps alot

Thank you this helps

I will try this soon

Okay, more like wwww!

Haven’t seen a conventional V belt in years, other than the belt on my lawn mower.

Multi V belt or Poly V belt;

Semantics . I’ve always considered “serpentine belt” to mean it has a belt tensioner. DIY’er me would refer to the above configuration (without tensioner) as an “accessory belt”.

It’s important to remember Toyota started to design this car in the middle 90’s as an entry level, inexpensive car for the world market. They clearly used well-proven older technology with the belt drive because it was less expensive, proven and easily maintained. And they were right. Those cars have done lots of solid service over the years and reinforced Toyota’s reputation as a manufacturer.

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