7 Symptoms Of A Bad Serpentine Belt (& Replacement Cost)

The serpentine belt transfers power to many different functions in your car, and therefore, a failed belt can cause some issues. Here's how to tell your serpentine belt is bad

Serpentine Belt Car

There are some parts in your car that are necessary for many functions to work at all. The serpentine belt is one of them.

But how do you know if the serpentine belt went bad?

In this article, you will find the most common symptoms of a bad serpentine belt, the location, and the replacement cost. Let’s begin with the signs to look for.

Symptoms Of A Bad Serpentine Belt

The most common symptom of a bad serpentine belt is warning lights on your dashboard. You may also notice heavy steering or squealing noises from the belt. If you see a lot of cracks on the belt visually, it’s time to change it.

Remember that your car might have two or more serpentine belts, which can cause some functions to work while some are not. Remember to check all belts if you try to look for any signs of damages.

Due to the serpentine belt’s importance, there are many symptoms you may experience when it goes bad or snaps off. Here is a more detailed list of the signs of a bad or failing serpentine belt to look for:

1. Warning Lights on dashboard

Battery Alternator Light

The first thing you imminently may experience if your serpentine belt is damaged or completely snapped off is warning lights on your dashboard. You will most likely notice the battery light because the serpentine belt powers the alternator, and if it stops, the warning light will appear.

You may also notice other warning lights like a power steering warning light or hydraulic pressure warning light.

2. Heavy steering

Heavy Steering

The serpentine belt in most cars powers the power steering pump. This will cause the power steering pump to stop working if your serpentine belt snaps off completely.

You will notice it because the steering becomes really heavy if it is not working, so heavy that it may actually be dangerous.

Most newer cars do have an electric power steering pump, though, and in this case, you will not notice heavy steering from a snapped serpentine belt.

3. Cracked serpentine belt

Cracked Serpentine Belt

The most noticeable symptom of a bad serpentine belt is that cracks start to occur on the belt. You can often see this directly by inspecting the belt. Some cracks might happen pretty fast even if the belt is not completely worn out, but it is definitely time to replace it if it is full of cracks.

4. Squealing sounds

Check Noise Under Hood E1609791600132

If your serpentine belt is not snapped off yet, but starting to go bad, you might hear squealing noises from the belt. This does especially occur when you are putting a load on the belt, for example, when you steer, so the power steering pump has to work.

You can try this by starting many electronic consumers like headlights, radio, heaters, etc. By doing so, you will make the alternator work harder, and if you hear even higher squealing, there might be something wrong with your belt.

Most newer car models have an automatic tensioner for the serpentine belt, but some older ones have a manual tensioner, which you might have to tension the belt to get it right and stop squealing.

RELATED: Idler Pulley Noise – Common Reasons & Information

5. Air condition not working

No Cooling From Ac

The serpentine belt also powers the AC pump, and if the belt snaps, you might notice that your car’s air condition stopped worked completely.

The AC pump often has its own smaller serpentine belt for just the AC pump in many car models, not in all of them, though. If you have a separate belt for the AC pump and it fails, everything else might work except the air condition.

6. Overheating Cooling system

Overheating Engine On Road

A lot of car models have the water pump powered by the serpentine belt. This applies more to older car models, but many new cars have their water pump powered by the serpentine belt, even though a lot of car models’ water pump is driven by the timing belt or chain.

However, if the serpentine belt drives your water pump and it snaps off, the coolant in your car will stop flowing, and your car engine will overheat very fast. This is fatal to your engine, and if you see that the temperature rises, you should stop imminently; otherwise, you risk damages like a bad head gasket or even worse.

7. Car Engine Stops Completely

Dead Car After Road

A car engine needs an alternator always to charge electricity to the car battery. If it is not charging, your car will die when the car battery runs out of electricity.

If the serpentine belt snaps off, the alternator will not charge electricity anymore, and if you keep driving, your car engine will stop running after a while. If your car battery light is on, you should definitely park your car and check what is wrong.

Serpentine Belt Location

Serpentine Belt Location

The serpentine belt is located on the front of the engine because the crankshaft pulley powers it.

Remember that the front of your engine does not always equal the front of the car. Your car can also be installed sideways, and this means that your car is located near the right fender of your car in most cases.

Serpentine Belt Replacement Cost

The average serpentine belt replacement cost is between $60 and $150, depending on the car model and labor costs. A serpentine belt costs $20 to $50 and labor costs $40 to $100.

However, what needs to be mentioned is that usually, when you replace the serpentine belt, you often want to replace some pulleys and the automatic tensioner if your car is equipped with one. This can be an additional $50 to $150.

It is recommended to check all pulleys and tensioners while replacing the belt to ensure they are functional and in good condition; otherwise, they may cause your new belt to fail very soon again.

Serpentine Belt Testing

FAQs about Serpentine Belts

Can you drive a car if the serpentine belt breaks?

No, it is not recommended to drive a car with a broken serpentine belt, even though you could potentially drive it for a while. The serpentine belt powers a range of components in the engine, including the alternator, water pump, and power steering. If the belt breaks, these components will stop working.

What does a worn serpentine belt sound like?

If your serpentine belt is worn or bad it will in most cases give a squeaky or squealing noise when the engine is cold, and in some cases it may not make any noise at all. However, if you hear any kind of unusual noise coming from your engine area, it’s definitely worth checking to see if your serpentine belt is the culprit.

How far can I drive with a broken serpentine belt?

You should not drive at all with a broken serpentine belt. If your serpentine belt breaks while you’re driving, you’ll probably notice it right away. Depending on the car engine type, the engine will start to overheat, the battery light will come on, and the power steering will stop working. You should pull over as soon as possible and call a tow truck.

Can you replace a serpentine belt yourself?

It is possible to replace a serpentine belt yourself, but it can be a challenging task on modern engines. In older car models there was a lot of space to replace the serpentine belt, but nowadays the space is often very limited. You may also need to change the belt tensioner when you change the belt.

Conclusion: Bad Serpentine Belt Symptoms

The main symptoms of a bad serpentine belt include:

  • Warning lights on dashboard
  • Heavy steering
  • Cracked serpentine belt
  • Squealing noises
  • Air condition not working
  • Overheating cooling system
  • Car engine stops completely
Magnus Sellén
Written by:

Magnus is the owner and main author of Mechanicbase. He has been working as a car mechanic for over 10 years, and the majority of them specialized in advanced car diagnostics and troubleshooting. Certified Automotive Diagnostic Technician.

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