Stresses and strains on the modern motorcar’s cam-belt


Smooth running of your vehicle’s engine is something that even the least sympathetic motorist desires, states motoring writer Iain Robertson, and while the clues might not be crystal-clear, the cam-belt’s age is a criterion.

Engine technology is a fascinating subject. Although very few of us ever lift the car’s bonnet to perform much more than a top-up of the windscreen washer-bottle, or to dip the oil-level, what sits beneath the branded plastic shroud is an immensely advanced piece of automotive engineering.

Most engines can operate, as long as they have been regularly serviced, for upwards of 100,000 miles, without incurring massive bills. Yet, an important aspect of engine maintenance is the replacement of its cam-belt. Although the actual replacement interval for this vital component can be every 50,000 miles, it does vary by make and model.

Unfortunately, it can be quite difficult to ascertain precisely when the cam-belt is worn. Wear can be detected by a squealing noise but that is not always the case. Although some engine manufacturers have reverted to the noisier type of chain-drive, cam-belts made of reinforced rubber that also drive other engine components remain very popular. Should it snap, you will not be driving any further and that is a good reason to stick to the manufacturer’s recommended replacement cycle.

In case you wondered, mileage is not the only critical measurement. As the cam-belt is produced from reinforced rubber, like car tyres, it ages naturally. If you only drive 5,000 miles in an average year, it might take ten years before you reach the 50,000 miles belt replacement time on a new car. However, the belt might be ready to break at around 35,000 miles.

If you are driving a second-hand car, it is always advisable to ask when the cam-belt was last changed (the details should be in its service book). For what it is worth, breakages often occur during sudden engine speed changes, such as moving off, changing gear, or just revving the engine at standstill.

As a visit to a Mr Clutch Autocentre will confirm, the cost of the cam-belt and even its mechanical components (tensioners and water pumps) is actually affordable. However, it is the labour cost that adds to the bill, because of dismantling and reassembly. Fortunately, Mr Clutch offers an all-in price (starting from £179.95), which goes a long way towards reducing the financial headache.

There is no easy fix, which is a good reason to put some cash aside, should your car be nearing its cam-belt replacement time, as that is the only means invariably by which to plan for an inevitable outcome. As with any automotive failure, preventative maintenance is the only viable cure. Yet, it is worth bearing in mind that Mr Clutch will help you to address the problems, often before they occur.

Prevention, in the case of a cam-belt replacement, is most likely the only cure. Therefore, it is always advisable to check your car’s mileage and its age before considering the right course of action.