What Makes a Belt Squeal?
Are you the one with the “noisy vehicle” that squeals every time you start your engine? Your engine belts make a screech or squeal noise usually because the rubber belt is slipping on the metal pulley and just like your tires spinning on the road, this causes noise. The belt may be slipping due to improper tension or because it simply has gotten old and the surface has become glazed, cracked or brittle. Damage to belts can occur from engine heat, improper tension, dirt, and general wear.
Why is belt tension important? Having the correct belt tension allows the belt to run properly along the pulleys at the right speeds and transfer the engines energy to power systems like air conditioning, alternator and water pump. Too little tension and the belts could come off completely, cause premature wear and in most cases, slip which causes noise.
How long can I drive with squealing belts? Any unusual engine or vehicle noise is cause for concern and should be looked at soon after the noise is first noticed. The earlier you catch a problem the less chance there is for further damage on that part or new damage to another engine part or system. Any reputable repair shop will inspect your belts at no charge and should be happy to ride along with you on a test drive if you notice the noise while driving.
When should I replace my belts? Replacing serpentine and timing belts should be parts of your vehicle maintenance plan Its best to regularly inspect your belts checking for premature wear. Pinch, squeeze and twist them, looking for cracks, fraying, splits or brittle places. On a serpentine belt, also look for missing grooves or places where the belt’s layers have separated. If you replace early when small amount of wear is found you can avoid a major repair later.A maintenance inspection performed during an oil change visit can reveal that a belt should be replaced. As with any recommendation to replace parts or service work ask that the service adviser show you what they find. Ask to see worn parts like a torn belt, trustworthy auto repair shop will be happy to take you to your vehicle and fully explain why they are making a recommendation.
updated March 7, 2016
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