2002 Toyota Avalon Chirping Sound

A couple weeks ago, I noticed a chirping sound upon startup coming from the alternator area that would go away eventually after 10 minutes when the car was warmed up. I replaced the alternator and the sound disappeared for about a week. Now, the sound is back again, but only after putting the car in gear. It’s not as loud as it was two weeks ago, but it’s still noticeable. Any ideas as to what could be causing the chirping noise?

My guess would be the serpentine belt or tensioner pulley. Changing the alternator just got the belt re-tightened and stopped the chirp temporarily.


Perhaps the best way to find out is by listening under the hood. While it apparently is not audible inside the car except in gear, it might be audible under the hood in Park…and don’t be afraid to rev the engine using the accelerator linkage.

How would one go about determining specifically whether it’s a belt, pulley, tensioner or alternator? The car only has 36,000 miles.

Age is playing a big part here. Belts should be replaced very few years. The tensioner is just a wheel on bearings and might as well be changed if you are changing the belts. My tensioner was causing a bird chirp sound on my 99 Camry.