Maintenance
When should the timing belt be replaced?
How to find the timing belt replacement interval, what a snapped belt does to the engine, which parts come in a timing belt kit and why the water pump is replaced at the same time.
The timing belt keeps the top and bottom of the engine turning in step. It often snaps without any warning at all. That is why it is not a part you replace "when it starts making noise"; you replace it when it is due.
How to find the replacement interval
The interval varies a lot between engines. Some engines specify around 60,000 km, others 120,000 km or more. There is also an age limit, because the belt ages even when the car is not driven. Get the exact figure from your car's service schedule or service book. If you buy a used car and there is no invoice for a timing belt change, assume it has not been done.
Belt or chain?
Some engines use a chain instead of a belt. A chain usually has no fixed replacement mileage, but its tensioner and guides can wear. A rattle from the front of the engine on a cold start is a sign of a worn chain tensioner; do not ignore it.
What happens if it snaps?
On many engines, the pistons hit the valves when the belt snaps. This leads to expensive damage such as bent valves and a damaged cylinder head. The price of a timing belt kit is small compared with that repair.
What is in a timing belt kit?
- Timing belt
- Tensioner pulley
- Idler (guide) pulleys
- In some kits, bolts and a water pump
On many engines the water pump is driven by the timing belt. Because the pump is accessible while the belt is off, replacing them together is common practice; if the pump fails later, you pay the same labour again. You can find matching parts in the engine & parts category by selecting your car.
FAQ
How many kilometres before the timing belt is replaced?
It depends on the engine; some engines specify 60,000 km, others 120,000 km or more. There is also an age limit. The exact figure is in the service schedule.
Should the water pump be replaced with the timing belt?
If the water pump is driven by the belt, replacing them together is recommended so you do not pay the same labour twice.
This guide gives general information. Torque values, fluid quantities and service intervals vary by vehicle; follow your owner's manual. If you are unsure about safety-related work, ask a mechanic.