Notice: Failure to follow the described timing belt inspection and maintenance may result in a broken timing belt and cause severe engine damage.
A Heavy Duty Register/Cold Start Counter function has been implemented to enable the scan tool to retrieve the recorded number of starts with the coolant temperature below -28°C (-20°F).
Check the cold start counter with a scan tool. If there are any cold starts visually inspect the timing belt for cracks. If cracks are noted, replace the belt and clear the cold start counter. If the belt is okay, and is not replaced, do not clear the cold start counter. Refer to the vehicle maintenance schedule for inspection intervals.
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. |
