Inspect the belt tensioner for the following conditions:
- If the belt squeals, the tensioner force may be insufficient. Check the belt length gauge, if the length is correct, replace the tensioner.
- If the tensioner clatters or rattles during engine operation, there may be internal interference or wear. Replace the tensioner.
- If the belt chirps, you may have a worn pulley or tensioner or cracks in the tensioner bas or arm. Check the mounting bolts, if they are okay, replace the tensioner.
Sticking or Seized Tensioner or Idler
- If the tensioner does not operate smoothly or doesn't move, you may have: internal thrust surface damage/wear, internal damage/wear, or a broken spring, replace the tensioner.
- Inspect the tensioner arm for cracks or other damage. If the tensioner is broken, it should be replaced.
- Look for excessive tensioner movement at idle, which can indicate internal wear, an out-of-round pulley or loose mounting bolts. Check the mounting bolts, it they are in good condition, replace the tensioner.
- Make sure the tensioner is not tilted or misaligned. Also make sure a gap exists between the tensioner arm and base. If you notice a problem, check the mounting surface, it the surface is okay, replace the tensioner.
- If the belt does not track properly on the pulley tracking surface, you'll need to troubleshoot the problem. Check the mounting bolts and the system alignment. Then, make sure the correct belt is being used for the vehicle. If all of these things are intact, replace the tensioner.
Belt Length Indicator
- A belt length indicator is built into each tensioner.
- The gauge identifies the effective operating range of the tensioner.
- It consists of a pointer and either two or three length marks.
- On a three-mark gauge minimum belt length, maximum belt length and ideal belt length are indicated.
- On a two-mark gauge only minimum belt length and maximum belt length are indicated.
- Ideal belt length on a two-mark gauge is generally half way between the minimum and the maximum.
- When a belt wears and stretches with age the tensioner will move towards the maximum belt length to maintain proper tension.
- As the pointer nears the maximum length mark, replace the belt.