Something squeals on my 4runner. I guess it's a belt somewhere, but I don't know for sure which one it is. I did a search and found a couple of posts with similar symptoms as mine, but with no clear answer to the problem.

The squeal is there when standing still, idling
The squeal is there if I depress the clutch pedal when driving
The squeal is not there with the clutch engaged
Depressing the clutch when standing still does not affect the squeal

I guess I'm looking for why the squeal goes away when driving, i.e. what part driven by a belt changes its operation from engine idle speed to normal operating speed. That should give an answer to what I need to do.

Anyone?

 

maybe the serpentine belt?

 

If you think it's a belt just remove them one at a time and see if it goes away.

 

At least the sound seems to come from that area. I'm not 100% it is a belt though, so any suggestions are appreciated, especially if they come with an explanation of my symptoms.

 

I would get a can of 'belt dressing' and spray it on each belt one at a time (while she's squealin') to try to narrow it down. If they all check out, you might want to start looking at your idler pulleys. When their bearings start to wear out, they squeal.

 

If your clutch effects it I would say it is either the through out bearing or the pilot bearing in the fly wheel. If it is the throwout bearing then when you push the clutch in it will squeal. If it is the pilot bearing then it would also squeal when clutch is pressed. If not that then it must be a belt.

 

Did some more testing on this today. It's basically only rpm related. At idle at about 750rpm, the squeal is there. Slowly increasing the throttle, the squeal intesity reduces and goes away at 1000 rpm. Wonder what that can be?

 

is it possible that at higher RPMs the idler pulleys move apart a bit, eliminating the squeal? how long since you've changed your drive belts? (just tossing some ideas out there...)

 

Could be I guess. I am due for a full belt change, timing belt included, so I should check that out.