Squealing while accelerating

Hello All,

All of a sudden I have a fairly concerning squealing happening on my 2000 4Runner. Began while I was climbing a grade but got progressively worse and makes it while accelerating on normal, flat terrain. Timing belt and serp recently replaced - not water pump. Engine sounds good when parked and accelerator cable pulled. Tranny fluid looks good.

Thank you and appreciate any advice.

 

Could be a pulley bearing, on one of the idler pulleys. Like for the alternator, or the AC. IIRC, there are three to check, Easiest way is to loosen the belts off, and try to turn the idler pulleys by hand. You may find one either totally jammed up, or with a high resistance to turning.

If you DO find a bad bearing, you can either replace the whole pulley assembly, IE pulley and bearing, or drive the bearing out and just replace that. Most auto parts stores carry the pulley/bearing pair, as well as the bearings alone.

Hope this is some small help...
Pat☺

 

Thanks Pat!!

 

Probably a loose belt. If you had a T-Belt change recently, the drive belts need retightening after a month.

Edit: What do you mean the Serpentine belt was replaced? That's not a thing on these is it? Just a T-Belt and old style drive belts.

 

Not sure? Thought it was one belt and looks like it to me but I’m a noob.

Thanks for the advice!

 

I'd wager the belts stretch further than the initial amount, but according to the FSM I've got, the belts are fully stretched after running on the truck 5 minutes.
If none of the idler pulleys are jammed up, definitely re-tension the belts. Don't worry about the timing belt, it has a variable tensioner on it, so it's maintained at the proper tension automatically. Just make sure the three drive belts are correctly tensioned.
They are tensioned by the idler pulleys, which are adjusted by loosening the idler pulley's central nut, then turning the adjustment bolt it rides on. Then tightening up the central nut again. After tightening the central nut, check the belt's tension again. It will change. You may need to adjust the belt's tension more than once to get it right. Once I get the belt tensioned correctly, and the idler pulley is good and tight, I relieve the tension on the adjustment bolt. Just a habit I got into. I don't recall who recommended it.

BTW: IF the three belts are correctly tensioned, but still squeak or squeal, you can apply some Ivory to them as they are running around. It'll silence them very well! Just gently apply the bar of soap to the two sides of the inner, V portion of the belt as it's running normally, so that it coats the belt completely. Only a very thin coating of soap is required.

Good luck, and keep us updated
Pat☺

 

Thanks again so much Pat. I’ll give it a shot and let you know the outcome.

Cheers!