What Happens To A Car When The Serpentine Belt Breaks?


A serpentine belt, also sometimes called a drive belt, is a more modern version of a fan belt that has many grooves inside them for better contact and reliability. Serpentine belts don’t break often, but if it does, what will happen to a car when the serpentine belt breaks?

If you want a quick answer on what happens to a car when the serpentine belt breaks or wondering how damaged your car may be from it. The answer is overheating, no power steering, no AC, or just outright engine failure, whether it happens now, or later.

In the old days, a car had several belts with each powering a certain part. When one broke, that one part didn’t work but the rest did. Since all cars now have one belt that powers many important vehicle parts, a broken belt means you have no torque for many different parts.

A broken belt can also mean big bucks in repairs because you may need to replace other parts damaged when they suddenly lost power. The vehicle will need to be towed too. 

While replacing a serpentine belt is a relatively simple process that takes about an hour or two, replacing a broken serpentine belt and fixing any damage caused by it can take days. It depends on how many pieces the belt broke into how it affected a multitude of car parts.

What Is a Serpentine Belt and What Does It Do?

The serpentine belt is a continuous single belt with many grooves inside that snakes around diffrent parts to make them run in unison. It is part of what keeps your car running smoothly.

A serpentine belt drives several important devices in the car including:

  • The Alternator
  • Water Pump
  • Air Pump
  • Power Steering Pump
  • A/C compressor

Those are just some of the things that depend on the serpentine belt.

The simplest explanation to what a serpentine belt is and does is it is a belt that powers all these things in the vehicle. It is constantly moving, rotating as the car is running. It transports power to all the vital vehicle parts from the air conditioning to the water pump. 

Related: Can You Jumpstart a Car With a Bad Alternator?

Symptoms Of a Bad Serpentine Belt

The serpentine belt, just like every other car part, will eventually wear out. It is important to pay attention to the symptoms of a bad serpentine belt before it causes big headaches. Some cars have check engine lights that illuminate when the belt gets worn. A bad serpentine belt would produce the following symptoms:

  • Sounds(Squealing, Chirping): Sounds like squealing coming from the serpentine belt is a clear sign that the belt needs replacement. Besides squealing, there may be a chirping when the belt starts slipping. Chirping and squealing happen because the pulley and the belt aren’t correct. It could be a stretched, damaged, or low belt tension.
  • Belt Slipping: You may feel it slipping or fluid will appear on it.
  • Loss of Performance: Another strong signal your vehicle needs to have its serpentine belt replaced is when the vehicle loses performance. It could be that the battery suddenly drains, or your power steering doesn’t work. Maybe the engine just quits working or works inefficiently
  • No Power Steering: The power steering is controlled by the serpentine belt, and steering without power steering can be quite difficult and dangerous.
  • No A/C: The prominent symptom of a worn serpentine belt is if the air conditioning stops working, or stutters.

You can also visually identity a bad serpentine belt by:

  • Fraying
  • Cracking
  • A glazed look
  • Rubber parts peeling away

So, What Happens to a Car When the Serpentine Belt Breaks?

There are many things that will happen to a car when the serpentine belt breaks, including:

  1. Power Steering Won’t Work: This is a dangerous situation if you are driving when this happens.
  2. Overheating: Another thing you will notice right away is overheating. That’s because the water pump quits working, so antifreeze quits circulating. An overheated engine will leave you on the side of the road waiting on a tow truck.
  3. Car Unable To Keep Running: A vehicle will not work without a serpentine belt. Everything will quickly shut down and the overheating could cause engine damage.
  4. Damaged Water Pump: The water pump can also be damaged if the serpentine built breaks.
  5. No Air Conditioning: Your AC compress will likely stop working with a bad serpentine belt and on a hot summer day, you would definitely regret not having a functioning AC.

To better understand what will happen, essentially everything listed in this serpentine belt diagram will either stop working or work inefficiently.

Dangers of Driving with a Bad Serpentine Belt

Since the serpentine belt controls so many devices in a vehicle, there are obvious dangers of having a bad belt. Losing power on a freeway or having an overheating engine while driving can not only put you in danger but can also cause others to wreck, depending on the situation. This is particularly true if you lose control of your power steering.

Related: What Happens When Your Car Overheats?

When Should a Serpentine Belt Be Replaced?

You should check the serpentine belt at least once every 5 years, depending on how much you drive. A car that is under continuous extreme heat and friction will need to be replaced more often. That can include vehicles in areas with extreme hot and cold temperatures or where cars are driven long distances at higher speeds regularly.

The good news is serpentine belts last longer than in the past. The rule of thumb is serpentine belts will hold up to between 50,000 and 100,000 miles. But if you start hearing loud squeals coming from the serpentine belt, you know it is time to replace it.

You can also check the belt to see if there are small cracks to determine when to change the belt. Small cracks don’t necessitate changing out the belt right away but are a good indicator that a replacement will be due soon.

Smaller cracks grow and it may serve your best interest to look at replacement if close to 50,000 miles on the current belt.

Most mechanics suggest replacing the water pump when they replace the serpentine belt. Part of the reason for that is the two parts tend to wear out about the same time.

The other reason is it is impossible in most cars to get to the water pump without moving the serpentine belt, so it is more cost-effective to replace the water pump while the belt is off.

How Much Does a Replacement Serpentine Belt Cost?

While prices range depending on the area, mechanics will charge between $100 and $200 to replace the belt. The part itself can cost between $25 to $75. You can also replace it yourself for free, apart from the part cost, as it is quite easy, all you have to do is just remove the old serpentine belt and then correctly place a new one, then the pulleys should automatically adjust to the new serpentine belt.

Hence is it better to replace a serpentine belt if you know it’s bad, as the expense of fixing the vehicle will dramatically rise as other parts may need replacing as well.

Does the Brand of Serpentine Belt Matter?

Many different brands of serpentine belts exist and some are better than others. Most mechanics tend to recommend the OEM ones because they are known to last longer. However, you can find lower-cost serpentine belts that are still of good quality.

The things to look for are belts that have high-quality rubber components. This is the most important aspect of a quality serpentine belt because good rubber will help it last longer and withstand more wear.

If you don’t want to experiment, just get the OEM ones.


You should to pay attention to the wear and tear on their serpentine belt. Replacing it before it causes damages will keep you and others safe, mean less damage to your car, and save you money at the auto shop.

If you got any questions or concerns, feel free to leave them below

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