What does a worn serpentine belt sound like?

A Worn-Out Belt or Worse?

Is that serpentine belt noise getting on your nerves? Perhaps you should worry instead and spring into action.

Belt noise typically indicates a worn-out belt or something more serious going on under the hood. Trying to ignore it, or worse using belt dressing to stop the noise without checking for the root cause of the problem is asking for trouble.

Here, you'll learn about the dangers of a squealing serpentine belt, its importance, how to check for wear and potential mechanical problems, and, if possible, how to fix it yourself.

Check the table of contents below and skip to the section you are interested in; or, simply read the sections in order (recommended):

  1. What Happens if My Serpentine Belt Snaps While I'm Driving?
  2. What is a Serpentine Belt?
  3. What Causes Serpentine Belt Noise?
  4. Checking the Serpentine Belt and Pulleys
  5. Serpentine Belt Repair and Cost

What Should You Do If Your Belt Is Squealing?

A damaged or failing serpentine belt is pretty serious and should be taken care of as soon as you notice it. 

If the belt completely snaps, then you could be stranded with an inoperable car because it’s tied to other essential systems. We’re always trying to avoid expensive tow-truck calls, so make sure to get your belt replaced as soon as possible. 

Even before complete failure, a faulty belt will significantly reduce the performance and safety of your car. With a suddenly depleted amount of energy in your power steering, you might find yourself struggling to drive as you’re used to, meaning that you’re more likely to be in an accident. 

It doesn’t cost too much to replace a serpentine belt either; for most cars, they could be in the $50 range, and your local mechanic shouldn’t take much more than an hour or so to replace it. 

The grand total to replace the whole system could be between $200 and $300, which is much more affordable than a tow. Not to mention any other system that a snapped belt may damage. 


What Can I Do If I Hear A Serpentine Belt Noise?

A damaged or failing serpentine belt that makes a squealing noise and is usually a serious matter. 

Contacting a mobile mechanic and repair service like RepairSmith is a great idea. It’s a convenient auto repair solution that’ll bring you the best quality serpentine replacement belt and install it.

With RepairSmith, you get:

  • Only ASE-certified and experienced technicians working on your vehicle
  • Advanced equipment and high-quality replacement parts used for your car’s repair
  • Quick and convenient online booking for all your repairs and services 
  • Upfront and competitive prices guaranteed
  • 12-month | 12,000-mile warranty on all repair and maintenance services

Wondering about the price estimate?Find out how much a RepairSmith serpentine belt replacement costs here.

1. Misaligned Tensioner Or Pulley

Common noise(s): Chirping

Common noise(s): Chirping

A misaligned tensioner or pulley throws the serpentine belt’s alignment of whack. So to prevent this from happening again, you need to identify the part that’s misaligned. To troubleshoot this issue, thoroughly inspect the tensioner and all pulleys.

  1. If the serpentine belt is wobbling, you can try to identify the source of the wobble. This will give you a good idea of which part may have a misaligned pulley.
  2. Give the tensioner and pulleys a visual inspection. Make sure that all the pulleys and brackets are properly tightened to the mounting surfaces.
  3. If you have an automatic belt tensioner, make sure that:
    1. The pulley turns freely without binding or wobbling
    2. The tensioner arm moves smoothly through its entire range of motion

If you determine that a misaligned tensioner or pulley is the problem, replacing it should do the trick.

How To Identify Serpentine Belt Noise

There can be quite a few reasons why you hear a squealing noise when you drive.To easily identify a serpentine belt noise, keep an eye out for these signs:

  • Check if the squeaking noise is persistent when you turn on your car, and it feels like it’s coming from the front of your vehicle (under the hood or from the engine bay). If yes, then the squeal you hear is from your serpentine belt or drive belt.The squeaky belt noise can become even louder or more aggressive if you accelerate suddenly or try to make a U-Turn. Rain or humidity can also make it worse. 
  • You can see other systems starting to struggle, like the alternator, water pump, power steering pump, etc.For example, if your engine overheats often and makes a rattling or squeaking noise, your water pump is failing (powered by a serpentine belt). Therefore overheating and a failing water pump could be a sign of a failing belt. 
  • If a lack of power steering accompanies your squealing belt, that’s another confirmation that the squealing noise comes from a serpentine belt. This will make it harder to turn your power steering wheel, and you’ll notice it immediately. 
  • And lastly, your air conditioning won’t operate if there’s a serpentine belt issue. So if you try to crank the cold air, but no cold air comes out, that’s a bad drive belt issue. 

Note: A bad serpentine belt alone won’t set off any dashboard lights, so it’s important to be alert for any failings in your car’s system. 

If you detect something, get it checked immediately as the serpentine belt directly influences vital engine components like your alternator and power steering. 

Final Words

The serpentine belt of your vehicle is a thick strip of grooved rubber and metal that winds around several engine accessories that are powered by it. This explains why it is responsible for many engine and vehicle functions. That said, a bad serpentine belt in your vehicle is something that you do not want to have. Simply put, a broken serpentine belt can be dangerous for you and the health of your engine and vehicle.

Thankfully several symptoms are associated with a bad serpentine belt. So once you can identify bad serpentine belt symptoms, you can manage the situation before it deteriorates. Your best bet is to have a seasoned automotive mechanic inspect your serpentine belt, belt tensioner, and engine components regularly.

Is It Safe to Drive with a Squealing Belt?

When the serpentine belt breaks, the vehicle may become inoperable, which would require an expensive tow and add to the overall repair costs. Plus, since the belt powers the power steering pump, a loss of pressure could result in heavy steering, which presents a safety risk when driving.

That’s why it’s recommended that the serpentine belt is replaced early when the squealing symptoms are first noticed.

Although it may be safe to drive with the squealing for a few days or weeks, the belt will eventually need to be replaced, and for safety, the earlier it’s repaired, the better.

Bad Serpentine Belt Symptoms

A bad serpentine belt can cause a lot of damage to your vehicle. So what happens to a car when the serpentine belt breaks? A lot of things. Here are some of the more common signs of a bad serpentine belt that you should look out for and resolve as soon as you can:

Squealing Sounds

Squealing Sounds

 One of the more apparent signs of a bad serpentine belt is when you hear sounds around your vehicle’s front area. This is often an indication that your serpentine belt is poorly adjusted and is slipping. It could also occur after the undercarriage of the vehicle has been washed. Usually, the squealing sound stops after a bit. However, sustained squealing sounds in the car’s engine area could well indicate that the belt is damaged. In such an instance, this high squealing sound is most noticeable when the vehicle ascends an incline. It is one of the bad serpentine belt tensioner symptoms that is hard to ignore.

Steering Problems

If your vehicle has Variable Assist Power Steering, then the serpentine belt is responsible for the power steering system’s functionality. The serpentine belt is responsible for powering the power steering pump so that it functions properly. Without power steering, it becomes difficult to steer your vehicle smoothly. You have to struggle with the steering before you can control the vehicle.

No Air Conditioning

The serpentine belt powers the AC compressor, so when there is a problem with the serpentine belt, your vehicle’s air conditioning will be affected. That is not to say that a failed serpentine belt is responsible when the AC is on, but there is no cool air from the air vents. Checking your serpentine belt is a great place to start if the situation arises.

An Overheating Engine

The engine is cooled by the water pump. Since the serpentine belt also powers the water pump, an overheating engine is another symptom that you should be wary of. When there is a problem with the serpentine belt, the water pump is not powered so it cannot pump the water needed to cool the engine. Over time the engine begins to overheat and could get damaged if it keeps running without a functional water pump.

Damaged Serpentine Belt

This is one of the visual indications that something is wrong with your serpentine belt. Any damage to the serpentine belt is a symptom that the belt needs a replacement. Serpentine belts are sturdy and are built to run continuously for miles upon miles. After a while, the wear and tear of running for so long begin to tell on the belt. This wear and tear are what causes a serpentine belt to break.

 This shows via cracked, damaged ribs, abrasions, and rib wear on the belt. So carrying out a physical inspection of the vehicle’s serpentine belt is a great way to confirm if your serpentine belt is about to pack up.

Whining Sound

Whenever you notice a whining sound that increases and decreases according to the engine’s speed, there might be a problem with the serpentine belt. When the belt is pulled too tight, there is a possibility of putting too much load on the bearings of the pulleys connected to the belt. The whining sound is a result of an overloaded accessory pulley. It is one serpentine belt noise that indicates that there is an issue with your serpentine belt.

Poor Driving Experience

Vehicle performance issues can also indicate a problem with your vehicle’s serpentine belt because bad serpentine belt causes loss of power. Indeed a problem with an overheating engine, the air conditioning or the power steering are different symptoms that reduce your driving experience. When you notice a combination of issues like rough idle, flickering lights when you start the engine, dimmed headlights, and difficulty in starting the vehicle (which mostly points to alternator issues) you want to check the serpentine belt. So if you have searched for answers to the question, can a bad serpentine belt cause rough idle? The answer is yes.

3. Mistake With The Belt Installation Or Tensioner Adjustment

Common noise(s): Chirping, squealing

Common noise(s): Chirping, squealing

It’s possible that the belt and all the parts are in good shape, but the belt wasn’t installed the right way. It’s also possible that the belt is too long.

The first thing you want to do is to look for the belt installation guide. It should be inside the engine bay (near the radiator) or on the hood. The guide will tell you which way the belt should be installed. Use it as a point of reference while inspecting the belt’s path. If you find that the belt’s path isn’t correct, you can reinstall it.If the belt’s path is correct, and if you’re still hearing noises, then the problem may be:

  • Fluid contamination on the belt (motor oil, power steering fluid, antifreeze, etc.)
  • Belt that’s too long
  • Loose belt tension

Let’s expand a bit on the last point. The problem may be as simple as the wrong tensioner adjustment. The tensioner on some cars has springs, so you don’t need to manually adjust it. If you have one of those, and if the adjustment is wrong, then it may be stuck. You can try using WD-40. If that doesn’t work, replace the belt tensioner. It’s possible that the spring has weakened.

If there’s a manual tensioner on the car, make sure that its tension is correct. The belt should have about half an inch of play for appropriate tightness. You should tension the belt during installation, and then re-tension it after 5 minutes of run-in.

Quick, Regular Check-Ups Are Key

To deal with belt noise, some drivers use belt dressing aerosol. However, getting rid of the symptom will only lead to a more expensive repair. You'll avoid this and similar belt-related problems by checking the belt regularly. Most car technicians recommend checking the belt whenever you need to replace the engine oil. However, I often check the belt and other accessories anytime I need to open the hood. Doing a quick check now and then will help you spot potential problems. Also, keep in mind the service interval recommended by your car manufacturer, and replace the belt according to schedule to avoid side-road trouble or, in some vehicle models, serious engine damage.

This article is accurate and true to the best of the author’s knowledge. Content is for informational or entertainment purposes only and does not substitute for personal counsel or professional advice in business, financial, legal, or technical matters.