Timing Belt: What Is It?

From jokes, music, and cooking to car parts and engines, timing is everything. In the case of car engines, a timing belt plays a crucial role in keeping things in sync. This belt makes sure that everything in the engine is operating smoothly to keep you safe on the road.


Although it is a simple component; it serves a valuable purpose and can ruin your day if it suddenly fails. As you probably already know, a broken timing belt spells disaster for your car’s engine. We understand that not every car owner may not know much about that, so we’ve gathered the most important things to know about this car component.

Timing Belt Components and Functions

A chain is to a bicycle as a timing belt is to a vehicle. It keeps all the internal moving parts of the engine in sync, and also powers the water pump, injection pump, and oil pump. It is a rubber belt with hard teeth interlocking with the two camshafts and the cogwheels of the crankshaft.


It works by synchronising the movement of the camshafts and crankshaft to ensure the engine intake and exhaust valves open and close in time with the pistons. If the camshafts and the crankshaft don’t operate in unison, the vehicle will not run smoothly. For instance, if the intake valves open too early, the vehicle experiences power loss and poor combustion as there may be too much fuel-air mixture flowing into the engine combustion chamber.


The combustion chamber also loses pressure and causes a power loss if the exhaust valves open too early. These engine components need to stay in sync. They might collide and damage each other if they don’t run in unison, which then results in costly repairs.


Are timing belts and timing chains the same?

You might have a timing chain instead of a timing belt, depending on your car model. Basically, a timing chain works exactly like a timing belt. Their only difference is that a timing chain is made of metal instead of rubber.


Timing belts are lighter, which is why they became popular to use in the 1960s when they were introduced in the car industry. However, timing chains are better in terms of lifespan and design. Many modern cars have timing chains in them instead of rubber belts.


If your vehicle has a timing chain instead of a belt, you can expect to go longer before replacing the chain. But to be sure, check your owner’s manual or consult the professionals. Timing belts don’t give out any warning signs before they break, so it pays to have your vehicle inspected regularly.


Are there possible indicators that it’s time to replace the belt?

As mentioned, there are no clear-cut signs that the belt is going bad. A timing belt failure is not a gradual decline but a sudden occurrence. The engine will immediately stop once the belt breaks.


Below are some possible indicators that the belt might need to be replaced:


⦁ Check engine light
⦁ Decreased engine power
⦁ Leaking oil
⦁ Overheating
⦁ Rubbing or squealing noises from the belts
⦁ Shaking or vibrating
⦁ Ticking noise from the engine
⦁ Trouble starting the vehicle


If you notice any of these, you should have your vehicle serviced just to be sure.


Why a Broken Belt Is Bad for Your Vehicle?

To support the points mentioned above, it’s worth noting that older vehicles use non-interference or free-running engines. This means that the pistons and valves in these engines never occupy the same space in the cylinder. Modern engines, on the other hand, are interference engines that allow the pistons to create even more compression.


The valves and pistons in these modern engines would occupy the same space in the cylinders if the pistons were fully extended and the valves were open. With the synchronisation of the crankshaft and camshafts, this overlapping doesn’t happen. But if the belt is broken, these parts will no longer be in sync.


In non-interference engines, this would lead to reduced engine power and even the eventual stopping of the engine. In interference engines, on the other hand, the pistons move up and strike the valves while they’re still open, resulting in serious damage to a variety of internal parts, which either needs to be repaired or replaced.


Sometimes, this can cause enough damage that it makes practical sense to just get a new engine (or a new car entirely) rather than repair the damaged parts. Although replacing the belt component is not that expensive, the process can be quite long and labour-intensive. Technicians will have to dismantle significant parts of the engine, check the seals, pulleys, and tensioners, remove the old belt and set the proper timing, and then reassemble the engine.


Get Your Vehicle Inspected at Aveley Garage & MOT Centre

From broken timing chains and belts to brake and engine issues, there is nothing we can’t fix. Our helpful team here at Aveley Garage and MOT Centre can get your vehicle up and running again. Turn to us for professional car diagnostics and repair services.


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