Squeal/Screech when Revving

[derola]

Not to long ago my 1992 FJ80 started with this gawd-awful squeal/screech if I give it a little gas while in neutral. It then escalated to happening from time to time when making sharp-ish turns and accelerating through the turn.

Trying to narrow down the source to see if this is something I can tackle in passing or needing to commit more time/money to it.

Thanks for any insights.

 

[HARDGEAR]

Need more descriptions. Mileage of truck, recent maintenance? Drives ok otherwise?
Does it happen idling in park? Or just neutral? When not driving, moving the steering wheel left and right?

Open the hood. Listen. Loose or worn belts can chirp and squeal. Sounds like the belts in front of motor? Behind the radiator fan. Could also be the power steering pump, worn out and moaning? Check the fluid level.
Don’t put your hand in there when running! Doh!

Shut off motor, get flashlight and check the belts closely for wear, no frayed edges or uneven wear. The belts should be fairly stiff to move 1/4 inch when pushed down on.
Have someone gently give it some throttle, turn steering wheel to replicate the noises.
I’m not a 3fe engine expert, and I cannot hear you truck from here! These are just common trouble shooting technics. Check You tube? Good luck.

 

[derola]

Need more descriptions. Mileage of truck, recent maintenance? Drives ok otherwise?
Does it happen idling in park? Or just neutral? When not driving, moving the steering wheel left and right?

Open the hood. Listen. Loose or worn belts can chirp and squeal. Sounds like the belts in front of motor? Behind the radiator fan. Could also be the power steering pump, worn out and moaning? Check the fluid level.
Don’t put your hand in there when running! Doh!

Shut off motor, get flashlight and check the belts closely for wear, no frayed edges or uneven wear. The belts should be fairly stiff to move 1/4 inch when pushed down on.
Have someone gently give it some throttle, turn steering wheel to replicate the noises.
I’m not a 3fe engine expert, and I cannot hear you truck from here! These are just common trouble shooting technics. Check You tube? Good luck.

So sorry - should have given far more context. Truck has 160K miles. Just replaced the alternator and all belts in the last 6 months. It does drive like a champ otherwise. I am not hearing any abnormal noises from power steering pump or anywhere else. All fluids are at appropriate levels too. In terms of other instances while driving - Yes this happen in park as well as accelerating while going uphill (but not all the time).

 

[t100boy]

3fe the belts need to be tight tight tight.

 

[HARDGEAR]

Alright so if there were new belts installed awhile back, hopefully oem Toyota ones, because they are the best, they can wear in some or stretch slightly over time. Are the belts loose. What is the belt condition?
They can make more noise under load.
If you could check the tension to see how much they may have slacked up a little. The belts should barely wiggle. Around 3/16 inch movement or play. Usually after a few hundred miles you should check them and retighten to compensate.
If the alternator was replaced it may have shifted on its mounting bolts. There is also a long bolt call the belt tensioner attached to the alternator. This will need adjustment to tighten belts.
Easy to do with a few sockets and 10 minutes.

 

[HARDGEAR]

3fe the belts need to be tight tight tight.

Does a 3f have a idler pulley? They seem to go out on a lot of cars in my experience. That may be the intermittent noise in this case. Some worn bearings can do this. Just speculating.

 

[derola]

Sorry for the radio silence but after a few days of troubleshooting we have a solution. The alternator bracket was bent which tweaked the pulley bolt causing odd tension on the drive belt. Fixed the brackets and replaced the bolt... no more banshee sound!

 

[John McVicker]

Could be a broken driver side motor mount.

Check the tips of your fan blade to see if they are touching the fan shroud during acceleration. If the motor mount is broken, the torque of the engine will allow the engine to lift up...with the fan hitting the shroud.

EDIT: oops, didn't see your last reply, sorry.