How Belt Tensioners Work

The drive belt tensioner in your car is a small component that works in conjunction with the serpentine belt to ensure that everything in your engine works as it should. From time to time, the tensioner should be checked to ensure that it’s set correctly. Your mechanic can do this for you as part of your routine maintenance. On occasion, it may have to be replaced.

What does the belt tensioner do?

In your engine compartment, the serpentine belt winds around various components, including your alternator, power steering pump, water pump, air conditioning compressor, and more. The tensioner ensures that the belt delivers enough tension while you’re driving, so that the belt can move the various pulleys that drive the engine components.

The parts

The drive belt tension is made up of four main parts – the base, tensioner arm, spring and pulley. The base holds the other parts, and the spring keeps the belt pulled tight. The pulley is what facilitates movement of the belt. The tensioner arm is found on the bottom of the tensioner, and if you press on it, it will work against the spring, delivering enough slack so that you can adjust or remove the belt.

Adjusting the belt tensioner

Adjusting the drive belt tensioner is not something you should attempt to do yourself – leave this job up to a pro. The serpentine belt is absolutely vital to the function of your vehicle, and if you end up with a belt problem due to an improperly adjusted tensioner, the damage can be catastrophic.


Next Step

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Recent Drive Belt Tensioner Replacement reviews

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Brian

23 years of experience
537 reviews
Brian
23 years of experience
Ford Escape L4-2.3L - Drive Belt Tensioner - Ponte Vedra Beach, Florida
Brian is timely. He is very knowledgeable. He does not try to upsell additional services. I would highly recommend him for your car needs!!!

Alejandro

9 years of experience
34 reviews
Alejandro
9 years of experience
Nissan Altima L4-2.5L - Drive Belt Tensioner - Whittier, California
Was amazing and professional. He did so much for us and stayed for so long. Idk what we would do without him. Went above and beyond.

Victor

15 years of experience
4 reviews
Victor
15 years of experience
Ford Focus L4-2.0L - Drive Belt Tensioner - Pensacola, Florida
Excellent service, cost more that original estimate but parts were bad and had to be replaced so no fault of the mechanic.

Chris

11 years of experience
38 reviews
Chris
11 years of experience
Toyota Camry L4-2.4L - Drive Belt Tensioner - Layton, Utah
Chris was really great to work with. On time. Friendly. Good recommendations on what needs to be done and what can wait. I'll definitely work with him again.

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Related questions

How Long Should Belts in My Car Last?

Depending on the type of belts in your vehicle, they will probably last you anywhere from 3-10 years, or 40,000-150,000 miles. Typically, you will find the drive belt replacement schedule found in the owner's manual. This is assuming that the...

Belt or bearing going bad.

The noise you are hearing is coming from one of the bearings of the tensioner pulley, water pump, alternator, A/C pulley and possibly even the power steering pump if the noise is a bearing noise. Sometimes just a belt noise...

Car is making noises from an unknown source. Possible alternator problem?

Remove the belt and check for noise. If the noise is gone, rotate the components that are associated with the belt. Check for smooth operation and noise. Noise that persists with the belt off could originate from inside the engine....

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