What is the Drive Belt Tensioner all about?

A Drive Belt Tensioner is a pulley placed to either a spring mechanism or to an adjustable pivot point that is made to keep constant tension on your serpentine belt. That is the big long belt in the front of your vehicle engine.

The tensioner rides on the outside surface of the belt tobring pressure, or tension, on the belt and against the pulleys that turn things like the alternator, power steering, air conditioner, etc.

Bear in mind:

Tensioners often come with pulleys; they are normally changed together. Also, when replacing a tensioner, the drive belt usually must be taken out. A mechanic may recommend changing the belt as well.

How it is done:

  • Inspect for any noise in the engine (usually a squeaky or grinding noise).
  • Take out the drive belt(s) (in most situations).
  • Check drive belt pulleys.
  • Inspect the drive belt tensioner.
  • Remove and change the tensioner if faulty.
  • Start vehicle to see if noise is gone.


Your car drive belt tensioner should always be checked when your drive belt is serviced. During routine maintenance and check, your drive belt system should be reviewed to make sure that all the part are in working order. The drive belt tensioner will usually last longer than the drive belts, so as long as your tensioner is checked or changed when your drive belts are, your belt system should remain in good order.

What common signs indicate you may need to change the Drive Belt Tensioner?

Unusual noise (squeaky or grinding sound) every time you start your engine.

How vital is this service?

The air conditioning, power steering, and alternator in your car are given power through the drive belt. The belt is connected to both the crankshaft and these systems, and sends power from the engine to drive each of these parts. The drive belt tensioner is responsible for keeping the tension in the drive belt, which lets it to continue moving and transferring power. When the drive belt tensioner fails, the tension in the drive belt will starts to diminish, and the car will not operate as well.