We've all heard of timing belts. We all know they are expensive to replace. But NOT replacing your timing belt in good time is far more expensive. Here is why...

The timing belt is a rubber band with rubber teeth on it. It winds around the crankshaft and the camshaft ensuring that their rotation is synchronised. To understand the importance of a timing belt you need to know a little about how an engine works. Knowing a little bit can help but don't worry, you don't need to be a mechanic to read on!

The intention of the engine is to turn the crankshaft which, via the gears, turns the wheels.

Car engines can have between 4-8 cylinders. Within in each cylinder is a piston. Each piston is attached to a connecting rod that is connected to the crankshaft.

The cylinders are little pressure chambers. At the top of each cylinder are valves that let air and petrol into the cylinder and exhaust out of it. The valves are opened and closed at different stages in the cycle of the piston's movement. The opening and closing of valves is controlled by the camshaft.

Each piston goes through 4 movements in a cycle:

1. In the first movement, the piston draws downward pulling air and fuel into the cylinder. At this stage the valves that let in air and fuel are open.
2. In the second movement, the piston returns upward putting the air and fuel mix under pressure.
3. At this point a spark ignites the pressurised air and fuel mix and creates an explosion forcing the piston down again.
4. In the fourth stage, the piston returns pushing exhaust out of the exhaust valve. At this point the exhaust valve must be open.

If the camshaft and the crankshaft are not synced perfectly, can you imagine what might happen? Well the cylinder might not receive a full amount of fuel and air and the exhaust might not properly escape. This would result in a less efficient engine. The car wouldn't go so fast and would use a lot of fuel. But worse than that, the pistons may collide with the valves and break them. This is very expensive to fix.

That is why it is very important to change a timing belt before it breaks.

Unlike other parts of the car, there are no symptoms to tell you that your timing belt is being worn down or about to break. The service guidelines in your manufacturers log book recommend when its time to replace the timing belt. If you can't find this information or are unsure whether your timing belt needs replacing you can easily contact your local mechanic at Temby Auto Service!