The serpentine belt plays a crucial role in transmitting power from the engine to important components such as the air conditioning compressor, power steering pump, and alternator. Engineered for efficiency and durability, this belt generally maintains its functionality for multiple years. However, with time, your belt may be damaged due to wear and tear. A bad serpentine belt produces different symptoms.
When the serpentine belt becomes worn or damaged, it can result in a loss of power for the engine. This article explains the bad serpentine belt symptoms, causes, and replacement cost.
What is a Serpentine Belt?
The serpentine belt is a continuous belt utilized in automotive engines to drive different peripheral accessories such as the air pump, air conditioning compressor, power steering pump, and alternator. It is also known as a fan belt or accessory belt.
The serpentine belt is a long and flexible rubber belt that rotates around different pulleys.
Starting from the crankshaft pulley, the serpentine belt rotates around some other pulleys attached to different devices, including the air pump, AC compressor, power steering pump, and alternator. The crankshaft pulley takes power from the engine and rotates the serpentine belt. When this belt gets power from the crankshaft pulley, it starts rotating and further turns other pulleys.
By using a serpentine belt, the engine can efficiently power all accessories simultaneously, eliminating the need for multiple belts and simplifying maintenance.
To maintain the proper tension of the serpentine belt, most cars use a serpentine belt tensioner. This component consists of a spring-loaded arm that puts pressure on the belt, ensuring it remains tight while running around the pulley.
The tensioner also plays a vital role in maintaining the belt’s alignment, which contributes to its longevity.
Symptoms Of a Bad Serpentine Belt
When the serpentine belt goes bad, it produces one or more of the following symptoms:
- Warning Lights on Dashboard
- Squealing Noises
- Cracked Serpentine Belt
- Heavy Steering
- Air Conditioning Stops Working
- Overheating Engine
- Black Smoke from Exhaust
- Car Dies While Driving
1) Warning Lights on Dashboard
The proper functioning of the serpentine belt is crucial for the operation of the alternator. The proper working of the battery is very important to properly charge the vehicle battery.
If the serpentine belt malfunctions, it can lead to issues with the alternator. Consequently, the car battery fails to charge, triggering warning lights on the vehicle dashboard.
The activation of the battery light may initially mislead you into suspecting a problem with the car battery itself. However, upon closer examination, it becomes apparent that the issue lies with the belt.
2) Squealing Noises
The squealing sound coming from your engine cabin is one of the common early symptoms of a damaged serpentine belt. If you notice unusual extreme squealing sounds, it is advisable to inspect your serpentine belt.
This squealing noise typically arises because of the worn or misaligned belt. This noise may also suggest that the belt may be slipping. Identifying this warning sign allows for the timely replacement of the belt, preventing more significant issues from occurring.
3) Cracked Serpentine Belt
Performing a visual inspection is one of the simplest methods to identify potential issues with the serpentine belt, even for those without mechanical expertise.
By visually examining the belt, you can easily spot signs of wear, regardless of your mechanical knowledge.
Look out for any visible cracks, separation, abrasions, or other forms of damage on your belt. The presence of such damage indicates an issue with your belt, and it is crucial to replace it before it completely fails.
4) Heavy Steering
The heavy steering is one of the clear symptoms of a bad serpentine belt. This belt plays a vital role in powering the vehicle’s power steering system. Without it, steering the vehicle becomes challenging, requiring significant effort.
Nevertheless, heavy steering may also occur due to many other reasons, such as a faulty steering rack, insufficient power steering fluid, or a bad power steering pump.
5) Air Conditioning Stops Working
The serpentine belt plays a crucial role in powering the vehicle’s air conditioning system. If you are unable to get cold air from the air conditioning vents, it may indicate an issue with the serpentine belt.
Since this belt also drives the compressor of the air conditioning system, you might mistakenly assume that there is an issue with the AC when, in fact, the problem lies with the belt.
In case of a faulty serpentine belt, you may also experience difficulties with other accessories powered by this belt.
6) Overheating Engine
An overheating engine is also one of the common signs of a bad serpentine belt. This belt is responsible for driving the water pump, which is responsible for circulating coolant throughout the engine to maintain optimal engine temperature.
When the belt breaks or becomes loose, the water pump won’t be unable to work effectively. When the pump doesn’t work properly, it doesn’t properly circulate the coolant, resulting in insufficient cooling and leading to engine overheating.
Engine overheating poses a serious risk of damage to the engine and other parts. Therefore, you should find the cause of the engine overheating promptly and fix the issue.
Read More: Engine Overheating Symptoms and Causes
7) Black Smoke from Exhaust
Under certain circumstances, the failure of the serpentine belt can lead to the emission of black smoke from your vehicle’s tailpipe. This occurrence typically happens when the belt is loose or has broken, resulting in engine overheating.
An overheated engine may lead engine oil to burn in the vehicle exhaust and give rise to various issues, ultimately resulting in the generation of black smoke from the exhaust.
8) Car Dies While Driving
When the serpentine belt of your car fails to drive the alternator, your car’s battery loses its ability to recharge. As a result, the car’s power supply gradually drains, eventually leading to the vehicle’s inability to run. Additionally, attempting to restart the car without sufficient power will likely prove unsuccessful.
To prevent this scenario, it is crucial when you notice any of the above-discussed signs, and you should address potential belt issues promptly. By taking proactive measures and addressing belt problems before the battery is fully drained, you can avoid being stranded.
Causes of a Bad Serpentine Belt
A serpentine belt goes bad due to one or more of the below-given causes:
- Normal Wear and Tear
- Excessive Load
- Improper Tension
- Damaged Pulleys
- Age of the Serpentine Belt
1) Normal Wear and Tear
Your serpentine belt may wear out with time because of regular use and exposure to contaminants, friction, and heat. As we discussed above, it is made of rubber. Therefore, it may deteriorate sooner, leading to glazing, fraying, or cracks.
2) Excessive Load
If your serpentine belt is exposed to heavy loads beyond its capacity, such as when using aftermarket accessories or modifications that increase power demands, it can cause the belt to wear out more quickly.
The contaminants such as the transmission fluid, engine oil, coolant, or dirt on the belt may lead to its early failure. However, a leakage from the engine parts, such as a leaking coolant hose or oil seal, may contaminate the belt and speed up its
The pulleys on that your serpentine belt move must be properly aligned. If your pulleys are misaligned or have an extreme play, they may ultimately lead to belt failure.
5) Improper Tension
If your serpentine belt is not suitably tensioned, it may cause unnecessary slippage or inadequate hold on the pulleys. Insufficient tension may lead to a worn or loose belt tensioner, incorrect installation, or a misaligned pulley.
6) Damaged Pulleys
A damaged or worn pulley may lead to uneven wear and excessive friction on the belt, which may lead to premature failure. However, your pulleys may damage due to insufficient maintenance, wrong installation, or debris.
7) Age of the Serpentine Belt
With the age of your belt, it may become more vulnerable to wear and failure. The service life of a belt depends on different factors, such as the belt quality, vehicle maintenance, and driving conditions.
Serpentine Belt Location
The serpentine belt location varies according to the vehicle’s make and model. The serpentine belt is typically located near the front of the engine and follows a specific path through multiple pulleys.
It connects the crankshaft pully to various parts, such as the AC compressor, water pump, power steering pump, and alternator. You can visually identify this belt as it winds its way through these components.
In the case of a car with a transverse engine, the serpentine belt is located to one side. The front of such engines may not be in the expected location. Consequently, the serpentine belt is usually situated closer to the right fender in this configuration.
To accurately determine the precise location and path of your serpentine belt in a particular car model, consulting the vehicle service manual is highly recommended. Additionally, understanding how the belt interacts with the different parts becomes important, particularly when it comes to replacing it.
Serpentine Belt Replacement Cost
The replacement cost of the serpentine belt depends on your vehicle model and the labor cost in your area. The average replacement cost of the serpentine belt is from $140 to $420. In this cost, the belt costs from $20 to $120, while the labor costs from $120 to $300. If you can replace the belt yourself, you may save the labor cost.
What is the function of the serpentine belt?
The serpentine belt is responsible for driving different engine accessories, such as the air conditioning compressor, power steering pump, and alternator. In few engines, the serpentine belt may also be connected to the engine’s timing system.
How long does a Serpentine Belt last?
The service life of a serpentine belt depends on various factors, including the vehicle’s driving conditions, the quality of the belt, and the vehicle model. On average, a serpentine belt can last approximately 5 to 7 years or between 60,000 to 100,000 miles. But if your belts are exposed to excessive chemicals, temperatures, or other challenging conditions, they may require replacement earlier than the expected lifespan.
What is the difference between a serpentine belt and a timing belt?
The timing belt is installed within the engine and plays a crucial role in synchronizing the camshaft and crankshaft. This belt makes sure that the engine’s intake valve and exhaust valve open and close in harmony with the piston, enabling the engine to work efficiently.
On the other hand, the serpentine belt is responsible for maintaining the optimal operation of the engine accessories. It makes a connection between the engine’s crankshaft and all other necessary engine accessories. It transfers the crankshaft’s power to all other necessary engine parts.
Can I drive my car with a broken serpentine belt?
Yes, it is possible to temporarily drive a car with a faulty serpentine belt, but it is not advisable. When this belt is damaged, your alternator will not work, and your battery won’t be charged. It may also lead the engine to overheat due to the lack of a working water pump.
What happens if the serpentine breaks while driving?
If your serpentine belt fails, several critical functions in the vehicle are impacted. Firstly, the alternator ceases to charge the car battery. Furthermore, a damaged belt may result in the loss of power steering and air conditioning, making the driving experience highly uneasy. Additionally, the water pump, responsible for engine cooling, stops functioning, leading to engine overheating.
Can the engine belt affect speed?
When the timing belt becomes worn, it adversely affects the engine’s starting speed since it is connected to the pulley that drives the crankshaft. Over time, the timing belt may slip on the camshaft drive, which may cause the engine cylinder valves to open and close at incorrect intervals, resulting in timing-related issues.
What does a damaged serpentine belt sound like?
A damaged or cracked serpentine belt may produce various noises, such as clunking, chirping, squealing, or squeaking, often resembling issues with engine-driven accessories or engine bearings. Chirps and squeals are the most commonly heard sounds associated with a worn or damaged serpentine belt, but they may also indicate some other underlying issues.
Does a bad serpentine belt affect engine timing?
Yes, a bad serpentine belt can affect engine timing, although the specific impact will depend on the design of the engine.
What are the benefits of changing the serpentine belt?
Replacing a worn or broken serpentine belt offers significant benefits in maintaining the engine’s optimal performance. By ensuring the belt is in good condition and properly aligned, the operation of essential car accessories, such as the power steering pump and alternator, remains unaffected and allows for smooth functionality.
What are the signs of bad Serpentine Belt?
- Warning lights on the dashboard
- Squealing noises
- Cracked serpentine belt
- Heavy steering
- The air conditioning stops working
- Overheating engine
- Black smoke from the exhaust
- Car dies while driving
Can a bad serpentine belt cause rough idle?
Yes, a bad serpentine belt can cause rough idle.