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Q: I have a whining squealing noise coming from somewhere in my pulley system and serpentine belt.

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I recently bought this car and had problems getting it started and there was a squeal or whine under the hood that coincided with acceleration. Upon inspection I found the battery was busted and was therefore replaced. I suspected that the alternator was overworking itself to make up for the busted battery. Cranked up immediately now but the squeal was still there but sounded somehow different. I checked power steering fluid even though the steering wheel moves freely. The fluid was low but not empty, and filled up to the c on gauge. No change in noise so I remove serpentine belt to manually spin each pulley. I started on tensioner and idler pulley because I have heard their springs and bearing tend to go bad around this mileage but spins freely. A/c, alternator, and water pump pulley spring freely with no noise also but the power steering pulley had slight play and made a single click. Is that normal? Also when running the tensioner pulley sometimes moves slightly up and down.

My car has 155000 miles.
My car has an automatic transmission.

If the noise changed when the battery was replaced, I would first suspect the alternator. Sometimes, when a bearing/bushing starts to go bad it will only make noise with the belt installed, as the tension can cause pressure to be applied to the affected area of the bearing/bushing.

Also, there typically shouldn’t be any type of clicking coming from the power steering and there really shouldn’t be any shaft play. When I am trying to find the source of a noise like this, I will use a stethoscope with an extended probe to isolate the source of the noise.

If you go this route, be extremely careful to avoid making contact with the pulleys or belt, to avoid injury. There are several possible causes for a noise from the front of an engine, so have a certified mechanic perform an inspection to determine the source of the noise.

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