8 Symptoms of A Bad Serpentine Belt (& Replacement Cost)

bad serpentine belt

The serpentine belt is an important component used in vehicles. In vehicles, the AC compressor, power steering pump, alternator, and water pump all run through the serpentine belt when the engine is started.

But often, as vehicles get older, sagging belts or belt wear are a normal process that can cause many vehicle parts to stop working. Sometimes, even a broken belt can cause the engine to overheat while the vehicle is running.

That’s why there should be complete information about the serpentine belts used in vehicles. What is a serpentine belt? What are the symptoms of a bad or loose serpentine belt, and how much does it cost to replace a serpentine belt?

What is A Serpentine Belt?

In vehicles, The serpentine belt drives the engine’s crankshaft along with the alternator, power steering pump, water pump, and air conditioning compressor. However, in many vehicles, the radiator fan is also driven by a serpentine belt.

Serpentine belts, also known as drive belts. In vehicles, serpentine belts are used to drive a number of peripheral devices associated with the vehicle’s engine.

The drive belt is called a serpentine belt because of its winding path around various pulleys in the engine compartment. Serpentine belts are made of embedded cords and fibers. Which provides flexibility to the serpentine belt and makes it more durable.

Symptoms of A Bad Serpentine Belt

Symptoms of a bad serpentine belt are belt squeaking, engine overheating, air conditioning system failure, alternator failure, and failure of other belt-driven components. In many cases, the belt will show cracks.

1. Squealing or Chirping Noise

Often, you will hear a high-pitched chirping or screeching sound due to a loosened or worn serpentine belt on any engine.

This noise is especially noticeable during startup or acceleration of the engine. Because a loose or worn serpentine belt usually starts making noises due to slipping on the pulleys.

2. Worn or Torn Belt


It is normal for serpentine belts in vehicles to wear or tear over time. Whenever you check for a damaged serpentine belt, you may notice cracking, fraying, or breakage in the serpentine belt.

A damaged serpentine belt can develop issues with multiple components in the vehicle failing or not working properly.

3. Steering Pump Failure

Many vehicles are equipped with a hydraulic power steering pump, which is continuously rotated by engine power with the help of a serpentine belt.

But when the serpentine belt of your vehicle is loose or broken, Then your vehicle’s steering pump fails to work, and it becomes harder to turn the steering wheel, causing the vehicle to face problems turning.

4. Battery Charging Light On


Whenever the serpentine belt of your vehicle is loose or breaks while the vehicle is in motion, the alternator driven by the serpentine belt stops working from engine power, causing you to have a constant display of the battery charging light on the dashboard of the vehicle.

The battery charging stops due to the shutdown of the alternator, and the battery starts discharging in no time. and reduced operation of a vehicle battery operated accessory.

5. Air Conditioner System Shutdown

ac clutch not engaging

Whenever your vehicle’s serpentine belt is loose or broken, Then your vehicle’s air conditioning system slows down or stops altogether.

Because of the loose serpentine belt slip, the ac compressor is not able to give full speed, or the ac compressor stops working completely due to the breakdown of the belt.

Causing your vehicle’s air conditioner system to work poorly or fail completely.

6. Overheating Engine Issue


The serpentine belt in any vehicle’s internal combustion engine also drives the water pump and circulates coolant through the engine to prevent overheating.

If the belt is loose or broken, the water pump may not work properly or stop working altogether.

This causes the engine to overheat. You may notice a temperature gauge rising to the red zone on the vehicle’s cluster meter or steam coming from the engine bay when this occurs.

7. Sudden Loss of Battery Charge

car battery cost

Some components of the vehicle are to be powered directly from battery power. These components require constant charging of the battery when the engine is running in order to remain functional and not discharge the battery.

But a loose or broken serpentine belt can stop your vehicle’s alternator from charging the battery.

And for this reason, continued use of the battery without charging it can dead the battery and cause the battery-powered accessory to perform dimly or fail completely.

8. No Response RPM Gauge

To see the RPM of the engine on the dashboard of a vehicle, an RPM needle gauge or digital gauge is fitted. This gauge detects the RPM as the engine accelerates and displays it in the cluster meter.

But in most vehicles, the rpm gauge works with the alternator. But the alternator stops working due to the breakage of the serpentine belt, due to which the rpm gauge also stops working.

Serpentine Belt Replacement Cost

Serpentine belt replacement costs can range from $90 to $180 on average for typical vehicles. The cost of a serpentine belt can range from $60 to $120, and a mechanic’s labor cost can be expected to average from $30 to $60.

  • Serpentine Belt Cost – $60 To $120
  • Mechanic Labor Cost – $30 To $60
  • Total Replacement Cost – $90 To $180

However, the make of the vehicle, brand of serpentine belt, and location of the mechanic can affect the estimated cost of serpentine belt replacement.

How Do I know if I Need To Replace My Serpentine Belt?

If your vehicle’s serpentine belt is worn or loose, you will notice serpentine belt squealing, engine overheat, air conditioning system failure, alternator failure and symptoms of failure of belt driven other components and in many and in many cases, the belt cracks. Based on these symptoms, you can determine that there is a need to replace the serpentine belt.

What Does A Serpentine Belt Do?

Often, the serpentine belt in vehicles drives the engine’s crank pulley along with other vehicle accessories and components. Such as alternators, AC compressors, water pumps, power steering pumps, radiator fans in many vehicles, etc.

The serpentine belt rotates from the engine crank pulley on the pulleys of all these components, so that when the engine is started, all these components of the vehicle are actuated by the serpentine belt.

But sometimes excessive loosening or damage to the serpentine belt can disrupt the functioning of many components of the vehicle, and these components stop working. In many cases, serpentine belt failure can also cause engine overheating.

Because the water pump stops or does not work properly, the flow of coolant stops in the coolant gallery of the engine, and the engine starts overheating. That’s why a bad or damaged serpentine belt must be checked from time to time.


Q. Can you drive with a broken serpentine belt?

A. Driving a vehicle with a broken serpentine belt is not recommended. Because it can cause damage to the engine of your vehicle.

Because you can drive the vehicle for 20 to 40 minutes with a broken belt. A broken belt causes the water pump to stop, which will cause the engine of the vehicle to overheat.

Q. Can a serpentine belt damage an engine?

A. Yes, a worn or broken serpentine belt can damage the engine. Because the water pump of the engine stops working due to a broken belt, which causes the engine to overheat quickly. If it is not taken care of in time, it can completely damage the engine.

Q. When Should The Serpentine Belt Be Replaced?

A. Typically, serpentine belts on vehicles must be replaced between 60,000 and 100,000 miles. But during every service, get the belt checked. If the belt is loose, tighten it.

Because a loose serpentine belt over a long period of time tends to wear more and may get damaged before its lifetime, However, the effects of weather can also affect the lifetime of the serpentine belt.

Short Summary

In vehicles, the serpentine belt plays an important role in the operation of the alternator, power steering pump, water pump, and air conditioning compressor on the engine’s crankshaft. When a vehicle’s serpentine belt is worn or loose, you will notice the symptoms of serpentine belt squealing, engine overheating, air conditioning system failure, alternator failure, and failure of other belt-driven components. Serpentine belt replacement costs can range from $90 to $180 on average for typical vehicles.

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