Timing Belt: Testing and Inspection

CAUTION: Failure to follow the described timing belt inspection and maintenance may result in a broken timing belt and cause severe engine damage.

CONDITIONS AND POSSIBLE CAUSES
When checking the condition of the timing belt, inspect for the following conditions and possible causes:
- Tooth is broken and/or tooth root is cracked- Camshaft jamming, damaged camshaft/crankshaft oil seal and/or coolant leak, old age, tensioner not functioning properly.
- Back surface of the belt is cracked/worn/scratched/scored-Excessive cold starts, tensioner jamming, overheated engine, interference with the belt cover.
- Side of belt surface is worn-improper installation of belt, overload or misalignment of cam drive components, tensioner jamming, heavy thrust loading against idler guide flanges, damaged idler guide.
- Teeth are worn-Poor belt cover sealing, excessive belt tension, tensioner jamming, rough and/or scored cam sprockets.
- Clean break across fibers-Kinked belt before or during assembly, foreign material under the belt.
- Oil/coolant impregnated and/or swollen belt-Poor oil sealing, coolant leak at pump, poor belt cover seal.