Timing belt
Definition
The timing belt is a toothed rubber belt that links the crankshaft to the camshaft(s), and often the water pump and injection pump, keeping valves and pistons synchronised. It is a service item replaced by time or mileage (typically 60,000-160,000 km or 5-10 years) together with tensioner, idlers and usually the water pump, because a failed idler or pump destroys the belt. Oil or coolant contamination, a weak tensioner and age cracking lead to skipped teeth or breakage; on an interference engine a snapped belt bends valves and can wreck pistons. Warning signs are ticking from the cover, oil leaking from cam or crank seals onto the belt and cam/crank correlation codes after a tooth jump. Codes: P0016-P0019 (correlation), P0340/P0335 (sensor faults), P0300 (misfire after a jump), P0011/P0021 (timing over-advanced/retarded).
Codes often stored
- P0011"A" Camshaft Position – Timing Over-Advanced or System Performance (Bank 1)
- P0016Crankshaft Position – Camshaft Position Correlation (Bank 1 Sensor A)
- P0017Crankshaft Position - Camshaft Position Correlation (Bank 1 Sensor B)
- P0300Random / Multiple Cylinder Misfire Detected
- P0335Crankshaft Position Sensor "A" Circuit
- P0340Camshaft Position Sensor "A" Circuit (Bank 1 or Single Sensor)