Hi, 2004 Tacoma 4.3L. I have a chirp/squeak from the front of the engine when it is idling, cold or warm. Took off all the belts and the noise is gone. All the pulleys (alt, ps and AC) seem to spin smoothly without noise. Belts look good but I am thinking of replacing anyway. Put it all back together with the old belts and the next day the squeak is back. When the engine is running its way hard to tell where the squeak is coming from, even with an auto stethoscope.

My question, How do you diagnose and find little squeaks and chirps without just replacing a lot of parts one by one? I want to make sure it is not a bearing making noise and just a belt but whats the best way to find where the problem is?

Thanks

 

I diagnose squeaks using a stethascope like you pointed out.
I would replace the belts and see if the squeak is still there.

If it's still making noise, check for TSB's (technical service bulletins). I work at Lexus and we have a couple for replacing pulleys for squeaks. If you spin them by hand they sound fine, but indeed are bad.

 

I have found from my experience that underhood chirps or squeels are most likely drive belts ; either too loose, too tight, old and hardened or contaminated with anti-freeze or oil ( or a combination )

the usual solution is adjusment, replacement, or treatment with spray-on Belt Dressing

 

If you not have access to a can of belt dressing ,you can try cleaning the belt with warm soap and water.If it gets better temporally it is a good indication the belt is bad.The cleaning might fix it if it is just contaminated.I just went thru this on a Jd tractor that had a antifreeze leak.

 

wait a minute.

there's 3 belts? did you try running one at a time?

 

Ran the belts one at a time, no squeak. When it was all back together it squeaked.

I ended up replacing all the belts with new toyota belts and the squeak/chirp is gone.

On my last 4runner I was always tracking down noises and it would drive me crazy. Thanks for all your suggestions!!!

 

glad to hear it worked out. my truck has belt noise too. it's an indicator my radio isn't loud enough.

i hate hearing unusual sounds as well, and i have to keep reminding myself that my 23 year old toyota will never be as quiet as my 14 yr old honda.

 

haha, the last time I let a noise go...SQUEEK BAM! my fan bracket bearing seized up on the interstate and all three belts snapped. That was on my 1993 4runner.

Since then I have been a little more paranoid when I hear new noises coming from the truck.