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.

Sources:

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

FAQs

What Is a Serpentine Belt? - What You Need to Know? ›

A car's serpentine belt helps power many of the vehicle's accessories, including the water pump, the alternator, and the power steering pump, to name a few. Older cars may have a serpentine belt that requires manual tightening to keep things running smoothly, but most modern cars have automatic belt tensioners.

What are signs of a bad serpentine belt? ›

Bad serpentine belt symptoms
  • Squeaking, squealing or chirping sound from under the hood of the car.
  • Check engine light or battery light is illuminated on your dashboard.
  • A/C isn't working.
  • Power steering isn't working.
  • The engine's temperature is high or overheating.
  • Smell of burnt rubber.

Can I drive with a bad serpentine belt? ›

Since the serpentine belt helps provide power to cool the engine, a faulty belt can cause the car engine to overheat as the water pump will not turn. As soon as the engine begins to overheat, have it inspected by a mechanic as it can cause a breakdown and cause engine damage if left overheated.

How do you know when a serpentine belt needs replacing? ›

Does One of Your Car Belts Need to Be Replaced? 6 Common Signs
  1. Squeaking and Squealing Noises. Worn-out serpentine belts tend to produce squeaking and squealing noises because they cannot handle the pulley tension. ...
  2. Play/Looseness. ...
  3. AC and Power Steering Failure. ...
  4. Overheating Engine. ...
  5. Visible Wear. ...
  6. Mileage Indicator.
Sep 24, 2021

How much does it cost to replace a serpentine belt? ›

But, what does a serpentine belt replacement cost? 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.

Can I replace a serpentine belt myself? ›

Serpentine belt replacement is easy because today's automatic drive belt tensioners eliminate the need to loosen bolts or pry components into position for retensioning. Just rotate the tensioner, remove the old belt and install a new one.

How often should a serpentine belt be changed? ›

When to Replace Serpentine Belt. When should a serpentine belt be replaced? The serpentine replacement interval is about every 60,000 – 100,000 miles. Because of their rubber material, serpentine belts will crack, peel, and wear down over time.

What happens if serpentine belt fails while driving? ›

The serpentine belt is a single, continuous belt that drives multiple devices in your engine, such as the alternator, power steering pump, water pump, and air conditioning compressor. If your serpentine belt breaks, all of these systems will shut down and your vehicle will overheat.

Does serpentine belt affect brakes? ›

On some vehicles it also runs the water pump, radiator fan, and power brakes. If your serpentine belt breaks, your battery won't last long. If it runs your fan or water pump, your engine could overheat before your battery dies. Steering and braking would also be affected.

How to tell if a belt is slipping? ›

A belt that has excessive wear or damage to it may produce a squealing sound when the engine runs. The squealing sound is most likely due to the belt slipping or a misaligned pulley. The noise is an indication that the belt needs to be replaced as soon as possible.

How long does it take for a mechanic to replace a serpentine belt? ›

Plus, replacement is relatively easy, and if you're wondering how long does serpentine belt service take, it's less than an hour for most vehicles.

What else should be replaced when replacing serpentine belt? ›

Most importantly, take the tensioner pulley and any idler pulleys (these are pulleys that do not drive anything, like Power Steering) and give them a spin.

What noise does a bad serpentine belt make? ›

One of the earliest signs of a failing serpentine belt is a high-pitched squealing or whining noise, especially during engine startup or when turning the steering wheel. This noise is typically caused by the belt slipping on the pulleys due to reduced tension or deterioration.

How to tell if a serpentine belt is loose? ›

One of the most common signs that your car's serpentine belt is going bad is squealing noises coming from the engine. The belt may be loose and need to be tightened, or it could be worn out and need to be replaced. If you hear squealing noises, it's best to take your car to a mechanic to have it checked out.

What are the symptoms of an over tightened serpentine belt? ›

Excessive Wear: A serpentine belt that is too tight can cause excessive wear on the belt and other components, leading to premature failure. The added tension can cause the rubber on the belt to wear down more quickly, which can cause the belt to crack or break.

Is it my serpentine belt or timing belt? ›

A timing belt has horizontal "teeth" that are made to fit both the crankshaft and camshaft. In contrast, a serpentine belt has multiple V-shaped grooves that appear vertically along the belt. Over time, these belts need to be replaced (roughly around the same time).

Does serpentine belt affect acceleration? ›

If the belt fails and the alternator stops charging the battery, the resulting electrical problems could affect the vehicle's overall performance, including acceleration. But you would probably have some larger warning signs. Air Conditioning Issues: The serpentine belt drives the air conditioning compressor.

Top Articles
Latest Posts
Article information

Author: Moshe Kshlerin

Last Updated:

Views: 6712

Rating: 4.7 / 5 (77 voted)

Reviews: 92% of readers found this page helpful

Author information

Name: Moshe Kshlerin

Birthday: 1994-01-25

Address: Suite 609 315 Lupita Unions, Ronnieburgh, MI 62697

Phone: +2424755286529

Job: District Education Designer

Hobby: Yoga, Gunsmithing, Singing, 3D printing, Nordic skating, Soapmaking, Juggling

Introduction: My name is Moshe Kshlerin, I am a gleaming, attractive, outstanding, pleasant, delightful, outstanding, famous person who loves writing and wants to share my knowledge and understanding with you.