A Drive Belt Tensioner is a pulley attached to either a spring mechanism or to an adjustable pivot point that is used to maintain constant tension on your serpentine belt. That is the big long belt in the front of your engine.
The tensioner rides on the outside surface of the belt to put pressure, or tension, on the belt and against the pulleys that drive things like the alternator power steering, car air conditioner repair
Facts to Note:
Tensioners usually come with pulleys; they are normally changed together. Also, when changing a tensioner, the drive belt usually must be detached. A mechanic may recommend replacing the belt as well.
How to Fix:
Examine for any noise in the engine (usually a squeaky or grinding noise).
Remove the drive belt(s) (in most cases).
Check drives belt pulleys.
Check the drive belt tensioner.
Take out and change the tensioner if defective.
Start car to see if noise is gone.
Your drive belt tensioner should always be examined when your drive belt is serviced. During routine upkeep and inspection, your drive belt system should be reviewed to make sure that all the components 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 shape.
Common symptoms indicating you may need to change the Drive Belt Tensioner:
Unusual noise (squeaky or grinding sound) every time you start the engine.
Importance of this service:
The air conditioning, power steering, and alternator in your vehicle are given power through the drive belt. The belt is fixed to both the crankshaft and these systems, and transfers power from the engine to drive each of these mechanisms. The drive belt tensioner is in charge of keeping the tension in the drive belt, which allows it to continue moving and transferring power. When the drive belt tensioner fails, the tension in the drive belt will begin to diminish, and the vehicle will not function as well.