Component Tests and General Diagnostics

Belt Tensioner-Mechanical
The only mechanical check that needs to be made is a check for tensioner stick grab or bind.
1. With the engine not running, check routing of the belt.
2. Detach the belt in the area of the tensioner.
3. Using the correct tool, move the tensioner from its relaxed position, through its full stroke and back to the relaxed position to make sure there is no stick, grab or bind, and to make sure that there is tension on the tensioner spring.
4. Rotate the tensioner pulley and check for a binding, contaminated or seized condition. Install a new tensioner if necessary.
5. Inspect the area surrounding the tensioner for oil leaks or contamination. Repair any leaks before installing a new tensioner. If the tensioner is contaminated, do not attempt to clean it as the damping mechanism inside may be damaged. Install a new tensioner if necessary.
6. If the tensioner meets the above criteria, proceed to test the tensioner dynamically. If the tensioner does not meet the above criteria, install a new tensioner.

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.