What Are Timing Belts and Chains and Why Are They Important?

When purchasing a used car, the standard questions asked are; The current miles on the car? When was the last full service completed? Does the car have any service history? current MOT status? and Has the timing belt or timing chain been replaced? What is the timing belt and timing chain so important and why is it to know if your vehicle’s belt has been replaced or not?

Timing belt

The timing belt is the ribbed belt that is located inside your engine. It is in a precise configuration by the manufacturer. The purpose of the timing belt is to keep the crank and camshafts timed correctly. This is so the top half and the bottom half of the motor synchronize and work accurately.

Difference between the timing belt and the chain

Not all cars have a timing belt and are using a timing chain instead. A timing chain has the same function as a timing belt except that it lasts longer. The manufacturers suggest that timing chains are replaced at mileage intervals. Although some timing chains do have a downfall as they are heavier and if they do fail, it tends to be catastrophic for the surrounding engine components.

Why replacement is necessary?

Now that we understand the difference between timing belts and chains, why is it so important to get them checked and replaced before the belt or chain breaks? The best answer to this is that the replacement will prevent any internal engine damage and catastrophic failure. When a car is out of timing, many components can touch each other that should not. For example, if a car is not kept in the correct timing then the valves could collide with the pistons causing damage and cylinder scoring and gouging. When any metal gets trapped in a cylinder it destroys everything. As a result of this, you will need a new complete engine replacement instead of just a timing belt or timing chain or find a trained technician who works for a certified car workshop in the UK that can rebuild the damaged engine. There are occasions where the damage is beyond repair and unfortunately, you will need to buy a new car.

If you look at your manufactures service book, that will guide you as to when the timing belt or timing chain needs to be replaced. The replacement recommendations are on the mileage or years since the car was built, whichever comes first. If you are unsure then you can ask your local car repair and maintenance garage where one of the trained technicians will be able to update you. If you do not have a local garage or a specific one, then you can search to book an online car repair service or car repair garage near you where the car mechanic can carry out a full diagnostic and health check on your car and recommend any car repair needing immediate attention and how soon the timing belt or timing chain needs to be replaced.

Often it is recommended to replace the water pump at the same time. The reason for this is to save you from the extensive labour costs and normally the water pump is located next to the timing belt. The timing belt or chain runs on the water pump as well.