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Serpentine belt squeals at first

Hi folks,

There’s a rubber belt that connects lots of stuff in my truck, I believe it’s the serpentine belt, and at around the 100k miles mark it began squealing when I first start the engine, especially when there’s been some rain. I can make the squeal go away by spraying the gears it connects to with WD40, and I curious as to whether this is something that needs urgent fixing instead.

Thanks for any advice.

Your overdue for a belt and tensioner change. The EPDM rubber belt wears differently and a belt gauge to check the spacing of the v-grooves is the proper way to check for wear. EPDM rubber doesn’t crack like the older-style belts and wear is near impossible to detect with just visual inspection. Here’s a good article from Gates.

Never spray lubricant on a serpentine belt. You need a new onr and probably a belt tensioner too/

And before you install it you may want to spray the oulleys down with some solvent. That WD40 leavs a lubricating residue that will not be conducive to a good Cf, and it also contains a solvent that might attack the polymers in the new belt.

Wow. I could swear it was the dealer that told me to spray the WD40.
Is the belt something that I can replace myself as an amateur or should I just take it to a local mechanic?

The belt change (and tensioner if you need it) is not very difficult if you are mechanically inclined. If you are not mechanically inclined and lack a repair manual then take the truck to an independent mechanic. You need to avoid any dealership that tells you to spray a serpentine belt with WD-40. Not a good idea at any time.

It should be easily replaceable, do not know your model.

You might have your battery tested too…A weak battery can make a belt squeal…

I noticed the AC compressor on my wife’s 06 Toyota Sienna was a bit noisy. I sprayed some water on the belt with the engine running and the noises stopped. The belt is 6 years old so it’s due for replacement. I’ve had good luck with Goodyear Poly-V Gatorback belts on my other cars.

Don’t use belt dressing or WD-40 on a belt. Replacing a belt on a Tacoma shouldn’t be too difficult.

Ed B.