Cam belts: their function and why not looking after them could negatively impact your car and your bank balance

What is a cam belt? 

Simply put, it’s a vital piece of the engine. Its job is to control the timing of your vehicle’s internal combustion engines. It’s also sometimes referred to as a timing belt.

Does your car have one? 

Some cars don’t actually have a cam belt and have a cam chain instead, for example, most BMW and Mercedes cars. Check your vehicle handbook or speak to your garage to find out if you have a cam belt or cam chain.

What’s the difference between a cam belt and a cam chain?

Weirdly enough, the main difference is the material. Cam chains are made of metal, housed inside the engine and lubricated by the engine oil. Whereas cam belts are usually outside the engine, however, some manufacturers are now using “wet belts” which run internally in the engine oil like cam chains. Cam chains can last longer than cam belts because they’re made of stronger material.

When do you need to replace a cam belt? 

This differs depending on the make and model of your car; your best bet is to check the manufacturer’s specifications, which will set out the necessary service intervals. These intervals can either be time-related or by the number of miles the vehicle has done (whatever comes first).

It’s so important that you follow the manufacturer’s requirements and get your cam belt replaced when it needs to be as the risks can be both costly and dangerous. It will cost you much less if you honour the recommended service intervals and get it replaced on time, than if you wait till it’s at breaking point – or breaks completely. If you don’t look after your cam belt, it can perish, damaging your engine. Take extra care if your car stops and starts a lot (if you take your car out on a lot of short journeys) or if you rarely use your car as this can cause the cam belt to disintegrate quicker.

Things you need to know: 

• Ensure you use a qualified technician to fit a new cam belt. As long as you take your car to a reputable garage, you should be fine. 
• Is the technician doing the job cam belt insured? If something goes wrong and they’re not, you may end up paying much more than you expected.
• A lot of cars nowadays require specialist tools to carry out a cam belt replacement. The technician doing your cam belt should have access to and be competent in using these tools. 
• DON’T FORGET a poorly maintained cam belt could destroy your engine.