Timing Belt Replacement

Function
There are two terms used to describe the types of engines that require a timing belt: non-interference and interference. Both terms refer to the interconnection of the valves and pistons when engine components are out of sync. When the timing belt fails in a non-interference engine, the valves and pistons will generally not cause severe engine damage. When the timing belt fails in an interference engine, the pistons will hit the valves and break, causing serious damage. If the damage is extreme, the engine may need to be replaced. If a timing belt failure occurs in either of these engine types, the vehicle will cease to run and will come to an immediate stop.

Timing
Timing belts will gradually deteriorate. Many other parts need to be removed when replacing a timing belt, making it a difficult task to thoroughly inspect the rubber without disassembly. Cracks or a worn appearance is an unquestionable sign the belt needs to be replaced. If the timing belt cannot be visibly assessed, the age of the belt should be used as a gauge for replacement. There are manufacturers recommendations for each type of engine. They usually range between 60,000 - 90,000 miles.

Monitor
Sensors from other components of the engine, such as the camshaft or crankshaft, can activate a warning light if the timing belt becomes worn. It is possible to hear screeching or slapping noises come from the engine if the belt is loose or worn; an adjustment to the belt may fix this issue, but the belt will need to be thoroughly inspected.

Recommendations
Due to the labor involved when replacing a timing belt, it is recommended that other parts requiring disassembly at the same time also be replaced. Those parts include: water pump, drive belt, engine seals, tensioners and idlers.