Squeal above 2000 RPM

Rene Niolet · Jun 16, 2020

Hi,
Driving below 2000 rpm everything is normal.
Above 2000 rpm get a loud squeal that sounds like coming from under hood.
During squeal if let up on accelerator and rpm goes below 2000 rpm squeal stops. Accelerate above 2000 squeal starts and below it stops?????
Bearing in alternator or power steering pump???
Any help appreciated.
Thanks.
67 Dodge Coronet R/T 440 HP.

turbine68rt · Jun 16, 2020

Are your belts properly tightened? Are there any signs of a belt rubbing on the fan pulley? Just some thoughts.

davek · Jun 16, 2020

take the belt off one at a time and see what happens.

Ranger16 · Jun 16, 2020

Or just spray a little water on the belts.......one at a time.

A stethoscope works wonders in finding noises. Every tool box should have one.

RJRENTON · Jun 16, 2020

Its likely that the belt(s) are worn out. As a belt wears, the sides start to glaze, and loose their effectiveness. IF the belt bottoms out in the sheave, due to age or the sheave groove is worn, the contact angle of the sheave will not grip the belt effectively and cannot carry the load, so to speak, resulting in slippage (squealing). The offending sheave will likely be the water pump as its contact angle for the drive belt is 90° or less.
Just my opinion of course.
BOB RENTON

Builderguy · Jun 16, 2020

Regular bar soap rubbed against each "V" side of one belt while it is running. Rev over 2000 Noise gone, that is your bad belt. Still squeals then apply bar soap to both "V" sides of the other belt. Noise gone, there ya go! Noise still there, you have a different problem. The soap will wear off and the noise will return. I use Irish Spring because I like the scent

RJRENTON · Jun 16, 2020

Builderguy said:
Regular bar soap rubbed against each "V" side of one belt while it is running. Rev over 2000 Noise gone, that is your bad belt. Still squeals then apply bar soap to both "V" sides of the other belt. Noise gone, there ya go! Noise still there, you have a different problem. The soap will wear off and the noise will return. I use Irish Spring because I like the scent

Do the job correctly.....just replace the belts....all of them....at the same time....and do not forget to re-tension them after a short run in to overcome the initial stretching.
BOB RENTON

Builderguy · Jun 16, 2020

The soap trick is just to confirm that it is a belt issue. Why buy new belts if a bearing is junk? Probably is a belt(s) but this test literally takes under 5 minutes to complete.

Mick56 · Jun 16, 2020

After a good session of having the belts squeal, quickly shut off the motor and touch each pulley. The pulley where the belt is slipping will be extremely hot!

ChryslerKid · Jun 16, 2020

Stock fan? If its an b/rb with the ac setup, Water pump/tensioner pulley/crank it can be a pain. Guy before me put a clutch and a seven blade to help cooling.The thing would always squeal above 2k no matter how tight until i put a 5 blade on.

RJRENTON · Jun 17, 2020

ChryslerKid said:
Stock fan? If its an b/rb with the ac setup, Water pump/tensioner pulley/crank it can be a pain. Guy before me put a clutch and a seven blade to help cooling.The thing would always squeal above 2k no matter how tight until i put a 5 blade on.

The amount of horsepower a belt is capable of transmitting (from drive sheave to driven sheave) is a function of the total cross sectional area the belt travels, the contact angle of the driven sheave and its RPM. IF these parameters are exceeded, belt squeal usually results. Failing bearings usually do not exhibit a squeal but manifest as a wobble and/or growling noise that remains steady at all speeds.
BOB RENTON

davek · Jun 17, 2020

So what was it?

Rene Niolet said:
Hi,
Driving below 2000 rpm everything is normal.
Above 2000 rpm get a loud squeal that sounds like coming from under hood.
During squeal if let up on accelerator and rpm goes below 2000 rpm squeal stops. Accelerate above 2000 squeal starts and below it stops?????
Bearing in alternator or power steering pump???
Any help appreciated.
Thanks.
67 Dodge Coronet R/T 440 HP.

1967coronet · Jun 17, 2020

Builderguy said:
The soap trick is just to confirm that it is a belt issue. Why buy new belts if a bearing is junk? Probably is a belt(s) but this test literally takes under 5 minutes to complete.

Plus your car smells better !

Squeal above 2000 RPM

Rene Niolet

Active Member

turbine68rt

Turbine Bronze Member

davek

FBBO Gold Member

Ranger16

Well-Known Member

RJRENTON

FBBO Gold Member

Builderguy

Builderguy

RJRENTON

FBBO Gold Member

Builderguy

Builderguy

Mick56

Well-Known Member

ChryslerKid

Well-Known Member

RJRENTON

FBBO Gold Member

davek

FBBO Gold Member

1967coronet

FBBO Gold Member

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