S-Type (X200) V8-4.2L (2005)
Drive Belt Tensioner: Testing and Inspection
Mechanical Testing
Accessory drive belt tensioner or supercharger belt tensioner-mechanical
The only mechanical check that needs to be made is a check for the accessory drive belt tensioner or supercharger belt tensioner 'slick, grab or bind'.
1. Remove the drive belt in the area of the drive belt tensioner.
2. Using the correct tool, rotate the drive belt 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 drive belt tensioner spring.
3. If the drive belt tensioner meets the above criteria, proceed to test the drive belt tensioner dynamically. If the drive belt tensioner does not meet the
above criteria install a new drive belt tensioner.