With so many moving parts inside and outside of your vehicle, you could be forgiven for forgetting about some of them along the way. Additionally, without an understanding of their function, you could even underestimate their importance. Out of sight, out of mind.

This is often the case with a timing belt. This component has a simple and maintenance-free design and, on the surface, doesn’t seem to do a whole lot. However, a broken timing belt is bad news for your four-wheeled friend. Furthermore, a worn-out timing belt will have a negative impact on your vehicle’s performance, fuel consumption, and, ultimately, its lifespan.

With that in mind, we’ve put together this complete guide to the often forgotten timing belt. This will include what it actually is, how to know when it needs replacing, and the cost and process of getting it replaced.

What is a timing belt?

A timing belt - otherwise known as a cambelt - has the task of ensuring both the crankshaft and camshaft rotation are working together harmoniously. If both of these are in sync, your vehicle’s pistons and valves will operate correctly.

This is extremely important for keeping your car’s internal combustion engine (ICE) working well. To explain why, let’s look at the steps of the combustion process inside a typical gas engine.

  • Step 1: Intake valves inside the cylinders of an engine open up and allow a mixture of fuel and air into the combustion chamber.
  • Step 2: Then, the valve closes, and the piston moves up the cylinder to compress fuel and air.
  • Step 3: A spark plug ignites the mixture and the combustion chamber pushes the piston down again.
  • Step 4: The exhaust valve opens up, allowing the waste gases to be pushed from the cylinder and the piston returns to the top of its stroke.

Now that we know the process, where does the timing belt come in? The crankshaft ensures that the pistons move in a rotational manner. Whereas, the camshaft ensures the valves are able to open and close properly. To ensure the combustion process is successful, these have to be in sync. This is what your car’s timing belt facilitates.

Is a serpentine belt the same as a timing belt?

A timing belt is not the same thing as a serpentine belt.

When you pop the hood of your car, the belt you see is your serpentine belt. On the other hand, you don’t actually see your timing belt. This is because it’s located inside your engine.

The serpentine belt’s primary function is to keep the engine’s accessories running smoothly and efficiently. It connects the crankshaft on the outside of the engine to several other parts, including:

  • The alternator
  • Power steering pump
  • Air conditioning compressor
  • The water pump

PRO TIP: Another way to tell the difference between timing belts and serpentine belts is their appearance. Serpentine belts are smooth, whereas timing belts have teeth.

Have a read of our blog on serpentine belt replacement to learn more.

Do all cars have timing belts?

Not all cars are fitted with timing belts. Some car manufacturers have now started to favor a timing chain rather than a belt.

The benefit of a timing chain is that it has greater longevity than a belt. A timing belt will last you between 60,000 to 100,000 miles, whereas a timing chain is good for around 80,000 to 120,000 miles. Also, as it’s not made from rubber, the timing chain is not affected by temperature change.

On the flip side, it’s heavier than a belt and, therefore, increases fuel consumption. Moreover, as its made of metal links, it needs to be constantly lubricated using engine oil. This means that you’ll have to check and replace your engine oil more frequently when carrying out routine car maintenance with a timing chain.

Most BMWs and Mercedes and all Cadillacs are just some of the car models that now use a timing chain.

How long does a timing belt last?

As mentioned before, there is a range in the number of miles you can drive before you need a new timing belt.  

A newer car mobile can usually go up to 100,000 miles before the timing belt needs replacing. However, older vehicles may need it replaced at 60,000 miles. That being said, these numbers change if your water pump goes bad. This is because the belt usually has to be removed to replace your car’s water pump.

When to change a timing belt?

This next one is tricky. Besides using the mile range mentioned above, there are no clear-cut signs that your timing belt needs replacing.

Timing belts don’t gradually decline. In fact, when they fail, it’s very sudden. If a failure occurs, your engine will either immediately grind to a halt or lose significant power. A problem with a timing chain is easier to identify. If it’s becoming loose, it may make a lot of noise and, if it breaks, you’ll usually hear a large crack.

However, not all is lost! There are some preventative measures you can take. Firstly, you should consult your vehicle manufacturer guidelines. This will tell you how often you should change your car’s timing belt.

Furthermore, you can also speak to a certified mobile mechanic. Here at FixMyCar, one of our mechanics can take a look at the condition of your timing belt and let you know if a replacement is needed - all from the comfort of your own driveway. Get a quote today!

How much to replace a timing belt?

The price of a timing belt replacement is largely dependent on the labor hours required to carry out the replacement and varies from car model to car model.

For example, for cars with a small engine, the labor is lower because the engine is smaller. However, for an SUV or a track, the engine is larger so it will take longer to disassemble and incur higher labor costs.

So, while a timing belt itself is around $50, the average cost for replacement is between $250 to $450.

Now, if you’ve looked at that figure and thought, “Forget that I’m going to replace it myself.” We’d strongly advise against it. Unless you have a lot of auto repair experience, a timing belt replacement is not something to simply tick off your car maintenance checklist. It should be handled by a professional.

A mobile mechanic needs to gain entry to the timing cover of the engine by removing various engine accessories - and then putting them all back together again. In addition, as mentioned earlier, a cambelt replacement also usually requires a water pump replacement, too.

There are just too many things that can go wrong. So, even if you’re a gambler, this is not worth the risk.

Bottom line

There you have it! We hope this guide has given you a better understanding of the ins and outs of this often forgotten - yet essential - component of your car’s engine: the timing belt.

Ensuring you carry out a timing belt or chain replacement within the time range suggested by your car manufacturer is a must. Otherwise, you run the risk of a more serious problem down the line or putting yourself and your passengers in danger.

If you’re nearing the milestone where you need a replacement, get a quote for a mobile timing belt replacement today.