Serpentine Belt vs Timing Belt

You may easily get lost in vocabulary when understanding your vehicle’s intricate mechanisms and inner workings. It is likely you know that there are belts in your vehicle; however, they all seem similar. Therefore, I can understand how the names may confuse you; it was the same for me as well.

The most important belts in your vehicle are the timing and serpentine belts. Do not let the names confuse you; I will provide an in-depth guide on serpentine belt vs. timing belt to clear out all your confusion.

What Is Serpentine Belt?

You can pretty much guess from the name that it is a thin rubber band that winds around your engine’s components, like a snake. Once you pop the hood, you will be able to see some parts of the serpentine belt. In order for your vehicle to run smoothly, it is crucial that the serpentine belt functions accurately as well.

serpentine belt definition

This belt keeps several different parts of the car running smoothly. You will be able to locate it on the engine block’s exterior. Interestingly, this belt functions and provides power by coiling around the other accessories.

What Is Timing Belt?

Unlike the serpentine belt, you will not be able to immediately see the timing belt when you pop up your hood. You will notice that this belt is at a deeper location in the engine compared to the serpentine belt. While the previous belt provides support and power, your vehicle’s timing belt can act as a bridge between the crankshaft and the camshaft.

timing belt specification

This sync and connection allow the vehicle to operate smoothly. Furthermore, this belt directly controls the openings and closings of the inner valves. As the name states, this belt manages the time when the valves will let air/fuel in or out accurately.

Serpentine Belt vs. Timing Belt

So you can kind of grasp how both these belts are crucial in keeping your vehicle functioning properly. However, there are subtle differences both in appearance and mechanisms of the two belts. You will be able to deal with your car with more confidence by understanding these two component’s characteristics. 

I will be talking about the belts, their function, advantages, disadvantages separately to make it easier for you. Let us start with the first one –

Serpentine Belt

This snake-like rubber band runs several components of the vehicle. Moreover, it operates to power your vehicle’s alternator, air conditioning compressor, water pump, etc. It assists and provides power primarily to the peripheral accessories of the vehicle’s engine.

  • How Does the Belt Do All These?

There are different types of pulleys in your vehicle, and this belt wraps around those pulleys in a snake-like manner. So how does it transfer power? Cylinders, pistons, and valves start moving during the combustion reaction phase of the engine. Your engine’s crankshaft controls the previously mentioned components.

serpentine belt lifespan

The belt’s connection to the crankshaft allows it to carry and transfer the power from the combustion process to all the other components. This methodical transfer of energy provides superior efficiency and allows all the parts of the engine to work in unison when you turn on the vehicle.

  • What Happens When the Serpentine Belt Fails?

The combustion phase creates power and heat that this belt can transfer to the other components. This transfer creates a perfect balance. Therefore, if the serpentine belt starts to fail, the engine will end up overheating, and eventually, it will stop running altogether. So automatically, the question comes to mind, when does the belt fail and how to prevent it.

serpentine belt problems

Usually, this belt may stop working due to long time usage. However, it might stop working if the engine leaks coolant and oil. There also may be cases of misalignment that can cause problems to the belt. You can fix these issues by replacing the belt in time.


  • Efficiently transfers power without too much energy loss
  • It does not require too much belt tension
  • It operates quietly


  • Since multiple components connect to it, its failure instantly damages some critical functions of the vehicle

Timing Belt

This belt does not look or function the same way as the previous one. There are teeth/notches on the inner portion of the belt, and this feature allows it to hold on to gears. Previously, I mentioned how the crankshaft movement allows the serpentine belt to transfer power. But how does that crankshaft move? It is where timing belts come in to play.

deference between serpentine belt and timing belt

One of the primary functions of the timing belt is its connection between the camshaft and crankshaft. There are four different phases in the engine. They are intake, compression, combustion, and exhaust phases.

The function of these phases alongside the methodical closing/opening of the valves allows the vehicle to run correctly. This belt contains durable materials like polyurethane, urethane, neoprene, etc. Such materials provide the belt with superior longevity.

  • What Happens If the Timing Belt Fails?

In some interference engines, the timing belt’s failure causes the camshaft to stop while the crankshaft is still moving. As a result of the camshaft stopping, the pistons end up hitting against the unopened valves. This failure will cause permanent or extensive damage to the engine.

In a sense, the failure of the timing belt seems worse than that of the serpentine belt. If you fail to replace the timing belt in due time, you will have to end up spending thousands of dollars on fixing the damaged engine.

timing belt problems

You can overcome this issue by making sure that the engine does not run too hot and no leakage occurs. I also suggest you keep track of the belt’s change interval from the manufacturer’s instructions. During regular car maintenance, make sure to check whether the belt is showing wear. Remember, it is better to spend a small amount on new timing belts than changing an entire engine.


  • It will provide the precise motion for accurate timing
  • It provides high mechanical efficiency, approximately up to 98%
  • This belt will not produce unnecessary noises while it functions


  • More expensive compared to the serpentine belts
  • Its capacity for power transfer is not very efficient

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It may not be easy to get used to the names of different mechanical parts of your vehicle. You might even need time to wrap these terminologies around your head, especially since there are different kinds of belts and pulleys.

However, since you now understand how the serpentine and timing belts function, you will have no trouble differentiating them. You will be able to identify why your vehicle suddenly stops working properly. Wherever you notice a problem, go through this serpentine belt vs. timing belt guide to manage that issue swiftly!

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