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Cambelts Part Two: Spotting a Faulty Cambelt

Cambelts Part Two: Spotting a Faulty Cambelt

One of the best ways to prevent dangerous and expensive breakdowns is to understand your car and how it works a little better. That doesn’t mean that you need to become a qualified mechanic overnight, but learning a little bit about what key parts of your engine do, and how to tell when they are going wrong, might come in very handy one day.

Last week we looked at the difference between cam belts, cam chains, and wet chains and what they do. This week, we will focus more closely on how to tell if your cambelt needs replacing, and what can cause your cambelt to fail.

Why do cambelts fail?

Auxiliary belt. A leading culprit in cambelt failure is the auxiliary belt, or aux belt. The auxiliary belt is a long rubber belt that keeps the peripheral components of the engine running smoothly, such as power steering, air conditioning, and water pump. Like the cambelt, the aux belt runs off the crank shaft pulley. With time, the aux belt can wear down and when this happens, fibres from the damaged belt can become trapped under the cambelt. This disrupts the cambelt’s connection to the pulley, making it jump or come off completely.

Wear and tear. Unless you change your car every 3-4 years, you are likely to need to change your cambelt at some point. While the process of changing a cambelt is relatively simple, cambelts are notoriously hard to reach, so if you are in doubt, get it checked out by a mechanic.

What happens if the cambelt fails?

The cambelt is one of the areas that your mechanic will look at when servicing your vehicle. If you don’t follow the recommended servicing schedule, the cambelt could deteriorate without being replaced. If this happens, you are at risk of the cambelt snapping. If this happens while you are driving, it could potentially be very dangerous as your engine could seize up, which will mean that your brakes and steering will also fail. The damage to your engine could be significant, too. Last week, we spoke about the cambelt’s role in synchronising the pistons with the valves and cylinders; a snapped cambelt could cause these to come out of synch and damage each other. In short, ignoring a failing cambelt will be much more expensive and dangerous than replacing it when you need to.

Signs you need to replace your cambelt

You may be religiously following your manufacturer’s recommendations but there are some signs that your cambelt needs to be replaced sooner rather than later. Cambelts don’t give much notice, so if you hear a rubbing noise from the engine, switch it off immediately and call an engineer; your cambelt could be about to go. A failed cambelt could also be the reason your car won’t start; call roadside recovery for assistance.

For more tips and advice, follow Trust A Garage on Facebook or Twitter and remember it is always better to be safe than sorry.

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