Car timing belt: how to check your cambelt
A car’s timing belt, also known as the cambelt, is a crucial part of your engine. Our expert guide will help DIY mechanics feel less intimidated as you look to service or repair your car.
What is a car engine timing belt?
The timing belt is a simple strip of rubber and metal that makes sure that the engine’s key moving parts are choreographed to millisecond accuracy.
Without your cambelt, metal is likely to smash into other bits of metal, valves will bend, connecting rods will distort and flex, cams will grind and graunch… and when the noise dies down and the dust settles, all you’ll be left with is scrap. In short, the health of your timing belt is paramount to your car’s ability to function.
There are of course exceptions. If you have a non-interference engine a snapped timing belt will be just that. A snapped belt. But because almost all engines in recent history are of the interference type, the risks are great. An interference engine is one in which the internal spaces are filled with different parts at different times in the ignition cycle. If they all fill up the space at once, game over.
Cambelt or timing belt?
A timing belt and a cambelt are the same thing, so there’s no difference. Some engines have a chain instead of a belt and in this instance it tends to be known as the timing chain.
A drivebelt, or to give it its full name: an auxiliary drivebelt or serpentine belt, is different. This is used to drive ancillary equipment such as the power steering, alternator, air-con etc. If this snaps the engine won’t be damaged, although you won’t be able to drive much farther with the alternator out of action.
Car timing belt: when to change?
A cambelt’s change interval is always shown as a number of years and miles. For example, the Citroen C4 Spacetourer with the 1.2 Puretech petrol engine has a timing belt interval of 62,500 miles/72 months.
Whatever your car’s cambelt/timing belt interval is, it’s important to change it as soon as you reach either of those numbers. So in the case of the Citroen above, if you get to six years but have only covered 40,000 miles, you need to change the belt now. And if you’ve covered 62,500 miles in four years you also need to change the timing belt.
