How to stop a squealing fan belt

Updated April 17, 2017

The fan belt on your vehicle is connected to the fan, the alternator and the water pump. It is a simple rubber device that takes lots of abuse. It eventually wears out and needs to be replaced. Mechanics recommend replacing the fan belt every two years or every 25,000 miles, whichever comes first. Fan belts are also sensitive to weather conditions and may eventually become loose over time. The result is a squealing noise occurring when the engine is turned on. Tightening or lubricating the belt usually takes care of the problem.

Open, and prop, the bonnet. Locate the fan and the fan belt, which are in front of the engine.

Check the tightness of the belt by pressing it down with your finger. The belt should feel firm and should give no more than 1/2 inch when you press down on it. If it is possible to press the belt more than 1/2 inch, it needs to be tightened.

Loosen the bolt on the alternator that holds the belt with an adjustable wrench. Place a long wrench or metal bar against the alternator, and pull it away from the belt, until the pulley tightens the belt. Tighten the alternator bolt. Test the tightness of the belt by pressing down on it with your fingers.

Turn the engine on, and allow it to run for a few minutes. If the fan belt is still squeaking, it needs to be lubricated. Leave the engine on, so the belt is moving. Spray the belt with an aerosol belt dressing for ten seconds. Allow the engine to run for a few minutes to see if the squealing noises go away.

Replace the fan belt, if the squealing noise continues.


Always be careful when working around a moving belt. Don't wear long, loose garments, and keep your hair pulled back.

Things You'll Need

  • Adjustable wrenches.
  • Long metal bar
  • Belt dressing
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About the Author

Robert Russell began writing online professionally in 2010. He holds a Ph.D. in philosophy and is currently working on a book project exploring the relationship between art, entertainment and culture. He is the guitar player for the nationally touring cajun/zydeco band Creole Stomp. Russell travels with his laptop and writes many of his articles on the road between gigs.