Belt Tensioner - Dynamic

The automatic belt tensioner can be checked dynamically as follows:

1. With the engine running, observe the belt tensioner movement. The tensioner should move (respond) when the air conditioning clutch cycles (if equipped), or when the engine is accelerated rapidly. If the tensioner movement is excessive without air conditioning clutch cycling or engine acceleration, a pulley or shaft is possibly bent, or out of round or the damper mechanism inside the tensioner may be damaged. Excessive belt rideout (uneven depth of grooves in the belt) can cause excessive tensioner movement. Check condition by installing a new belt. For additional information, refer to FRONT END ACCESSORY DRIVE (FEAD) - EXPLODED VIEW  and ACCESSORY DRIVE BELT .