Cambelt and timing belt replacement

The cambelt, also called a timing belt, keeps the top and bottom of the engine turning in step.

What cambelt replacement means

It is a rubber belt and it has a service life in both miles and years. On most engines, if it breaks the valves and pistons meet and the damage is expensive, which is why it is replaced to a schedule rather than when it fails. The water pump is usually driven by the same belt and is changed at the same time.

What the job covers

Timing belt replaced to the manufacturer interval
Water pump replaced at the same time
Tensioners and idler pulleys
Auxiliary belt replacement
Timing checked and locked to specification

When you might need it

The mileage or age in your handbook has come round. Time matters as much as miles, because rubber ages.
You have bought a used car with no record of the belt being done.
A squealing or rattling from the belt cover, or a coolant leak near it.

What it costs, and what changes the price

Typically £350 to £800.

Engine layout is most of it. A belt reached easily costs far less in labour than one behind an engine mount.
Doing the water pump and tensioners at the same time costs more in parts and almost nothing extra in labour, which is why it is usually recommended.
Some engines use a chain instead, which is a different job.

How long it takes

Half a day on most cars, a full day on some.

Common questions

What happens if it breaks?

On most engines the pistons strike the valves and the engine needs major work or replacing. That is the whole reason for the schedule.

How do I know if mine has been done?

There is often a sticker under the bonnet with the date and mileage, and it should be in the service record. If there is no evidence, most garages will advise treating it as due.

Should the water pump be done at the same time?

On engines where the belt drives the pump, yes. The labour is already paid for, and a pump that fails later takes the new belt with it.