What Is a Serpentine Belt? - What You Need to Know (2024)

A serpentine belt is a vital part of your car’s engine. It is responsible for transferring power from the crankshaft to various parts of your car such as the alternator, power steering pump, air conditioning compressor, and water pump.

Without a properly functioning serpentine belt, your car will not run smoothly and may even break down. In this article, we will discuss what a serpentine belt really is. And what does a serpentine belt do? Where is the serpentine belt, and how long does your serpentine belt last?

What Does A Serpentine Belt Do?

A serpentine belt delivers power to your alternator, power steering pump, and air conditioning compressor. In some cases, it also supplies power to your water pump. In most cases, it features a serpentine belt tensioner that ensures your serpentine belt is at the optimum tension to move power around your engine blow efficiently.

What Is a Serpentine Belt? A serpentine belt is a long, winding rubber single belt that runs around several pulleys, as opposed to multiple belts that are used to drive each accessory individually.

The serpentine belt is connected to the crankshaft pulley, which is driven by the engine. From there, the belt runs around other pulleys that are connected to various accessories, such as the alternator, power steering pump, and air conditioning compressor. This allows the engine to power all of these accessories at the same time, rather than having multiple belts that need to be installed and maintained.

The serpentine belt is designed to be efficient and durable, and it typically lasts for several years. However, over time, the belt can wear out, become loose, or even break. A worn or damaged serpentine belt can cause the engine to lose power, or cause the accessories to fail.

To ensure that the serpentine belt is running at the correct tension, most vehicles have a serpentine belt tensioner. This is a spring-loaded arm that applies pressure to the belt, keeping it tight as it runs around the pulleys. The tensioner also helps to keep the belt in proper alignment, which can help to prolong its life of the belt.

It’s worth mentioning that in some cases, the serpentine belt also supplies power to the water pump which is responsible for circulating the coolant through the engine and the radiator. This is why a serpentine belt failure is a problem for the accessories and the engine’s cooling system.

Serpentine Belt Diagram

The purpose of a serpentine belt diagram is to provide a visual representation of the belt’s routing for reference during installation, maintenance, or replacement of the belt. It can also be useful for identifying which pulley or component a squealing or slipping belt may be associated with.

What Is a Serpentine Belt? - What You Need to Know (1)

It’s important to consult the owner’s manual or a repair manual for your specific make and model for the correct serpentine belt routing diagram, as routing can vary between different vehicles.

How long does a serpentine belt last?

On average, a serpentine belt can last between 60,000 to 100,000 miles or 5 to 7 years, according to West Brook Toyota. However, if the belt is exposed to extreme heat, cold, or chemicals, it may need to be replaced sooner.

The lifespan of a serpentine belt can vary depending on several factors such as the make and model of the vehicle, the quality of the belt, and the driving conditions.

It is recommended to check the condition of the serpentine belt at regular intervals, such as during routine vehicle maintenance, and to replace it if it appears to be worn or damaged.

However, some belts are manually tensioned and may need to be adjusted. Others have a self-tensioning mechanism that can experience wear over time and may need to be serviced. One thing to remember: in most cases, if the belt breaks, the vehicle will stop running.

7 Symptoms of a Bad Serpentine Belt

When the serpentine belt becomes worn or damaged, it can cause various symptoms that can negatively impact the vehicle’s performance.

According to jiffy lube Indiana, Signs you may need a new serpentine belt:

1. Loud noise or screech from under the hood, particularly when you accelerate.

This noise is caused by the belt slipping on the pulleys, which can damage the belt or cause it to break. When the belt is loose or worn, it can slip on the pulleys, which creates a squealing or screeching noise. This noise is typically heard when the vehicle is accelerating, and it can also be heard when the vehicle is idling.

2. Serpentine Belt shows signs of fraying, cracking, splitting, or glazing.

Visible signs of wear on the belt, such as fraying, cracking, splitting, or glazing, are another symptom of a bad serpentine belt. Fraying occurs when the edges of the belt begin to shred or unravel. Cracking occurs when the belt develops deep grooves, which can weaken the belt.

Splitting occurs when the belt develops a separation along the length of the belt. Glazing is when the belt appears shiny or glossy, indicating that the belt is worn down from friction.

3. Engine components such as power steering cease to operate.

The serpentine belt powers various engine components such as power steering, water pump, air conditioning compressor, and alternator. If the belt fails, it can cause one or more of these components to cease operation.

For example, if the belt that powers the power steering pump fails, the power steering system will not work, making it difficult to steer the vehicle.

4. Engine overheats.

The serpentine belt also cools the engine by driving the water pump. If the belt breaks or comes loose, the water pump will not function and the engine may overheat.

An overheating engine can cause serious damage to the engine and other components, so it’s important to address this issue as soon as possible.

5. Check the engine light or other warning lights displayed.

A check engine light or other warning lights may also be displayed on the dashboard, indicating a problem with the belt or one of the engine components it powers.

These warning lights are designed to alert the driver to a potential problem, so it’s important to address the issue as soon as possible.

6. Engine stalls.

In extreme cases, the engine may stall due to the loss of power from the serpentine belt. If the belt snaps or comes off, the engine will lose power to all the components that it is powering, and the engine will stall.

7. Black smoke from the exhaust.

In some cases, black smoke may be seen coming from the exhaust due to the failure of the serpentine belt. This can happen when the belt is loose or has snapped and is causing the engine to overheat. Overheating can cause the oil to burn, and it can also cause other problems that can cause black smoke to come from the exhaust.

It’s important to have the serpentine belt inspected and replaced if it shows any signs of wear or damage to prevent these issues from occurring.

A worn or damaged serpentine belt can cause a variety of problems that can negatively impact the vehicle’s performance and can also lead to costly repairs if not addressed in a timely manner.

What Happens to A Car When the Serpentine Belt Breaks?

If your serpentine belt wears out, is damaged, dirty, or breaks, engine accessories will not be able to rotate at the correct speed, resulting in reduced electrical system performance.

This can result in a sudden loss of power assistance to the steering system, causing the steering wheel to suddenly become very difficult to turn. A broken serpentine belt can prevent the water pump from circulating coolant through the cooling system, causing the engine to overheat.

And it can cause the alternator to stop producing power to run the vehicle’s electrical/electronic systems and recharge the battery – the headlights dim, the radio doesn’t work and the battery dies.

How Much Does It Cost to Replace a Serpentine Belt?

The cost of the serpentine belt itself could be around $50 and the cost of labor could be around $150. As a result, a serpentine belt cost for replacement could range from $70 to $200 depending on your exact model and where you get it replaced.

However, for luxury or high-end vehicles, the cost can be significantly higher. For example, the cost for a serpentine belt replacement on a luxury vehicle can range from $200 to $600.

It’s also important to note that the serpentine belt is not a standalone part and it may require other components to be replaced as well, such as the idler pulley or the tensioner, which can add to the overall cost.

It’s always recommended to check with a certified mechanic or dealership for a specific quote, as prices can vary depending on location, vehicle make and model, the year of the car, and the labor rate of the mechanic.

Should I Replace the Belt Myself?

Whether or not to replace a serpentine belt yourself depends on your level of mechanical experience and the tools you have available.

If you are comfortable working on vehicles and have access to the necessary tools, replacing a serpentine belt can be a relatively simple task. However, it’s important to have a good understanding of the process and the proper tools, such as a serpentine belt tool, to ensure that the job is done correctly.

If you are not comfortable working on vehicles, it’s best to have a professional mechanic replace the belt for you. This will ensure that the job is done correctly and will also prevent any potential damage to other components of your vehicle.

It’s also important to note that in some vehicles, the serpentine belt is difficult to access and requires special tools or knowledge to be replaced. It’s always best to check the vehicle’s repair manual or consult a professional mechanic before attempting to replace the serpentine belt on your own.


What Is a Serpentine Belt? - What You Need to Know (2024)


Top Articles
Latest Posts
Article information

Author: Reed Wilderman

Last Updated:

Views: 5748

Rating: 4.1 / 5 (52 voted)

Reviews: 91% of readers found this page helpful

Author information

Name: Reed Wilderman

Birthday: 1992-06-14

Address: 998 Estell Village, Lake Oscarberg, SD 48713-6877

Phone: +21813267449721

Job: Technology Engineer

Hobby: Swimming, Do it yourself, Beekeeping, Lapidary, Cosplaying, Hiking, Graffiti

Introduction: My name is Reed Wilderman, I am a faithful, bright, lucky, adventurous, lively, rich, vast person who loves writing and wants to share my knowledge and understanding with you.