Causes of a Scraping or Squealing Noise While Driving

Most of us who are driving cars are most likely familiar with that scraping or squealing noise that our cars make from time to time.

What exactly are the causes of a scraping or squealing noise while driving? Let’s find out.

What Kind of Noise Is It?

If you don’t drive too often, you may not know what the scraping noise really sounds like until it becomes extremely loud.

The louder it becomes, the worse the problem is, so it’s better that you nip it in the bud while it is still controllable.

For those not familiar with cars, it is basically a high-pitched squealing sound that sounds like a pig’s squeal.

It may start off very weak at first, but the more the sound is ignored, the louder it gets.

Woman on red mechanical creeper

This is then usually followed by a low grinding noise that may come from under the hood. This most likely means that something is worn out.

What Causes These Squealing Noises?

The causes of a scraping or squealing noise while driving depends on which part is affected.

In order to fully understand the root cause of the squealing, it is very important to look into all parts of your car to fix the noise.

These are the causes to look into in the event of a scraping noise.

A Faulty Accessory Belt

The most likely cause of the noise is a faulty accessory belt. If the high-pitched squeal comes from the engine bay when you try to accelerate the car, then it means that your belt is probably near depreciated.

The most practical thing to do is to change the affected belts right away so that it doesn’t affect the other parts.

If you don’t have a spare belt at hand, you might want to go to the nearest service station to get it fixed.

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Faulty Brakes

If you hear high-pitched squealing when you apply your brakes, then there is definitely a problem in that area.

Brake problems need to be solved right away because you rely on your brakes to stop.

mechanic fixing a car break

If your brakes don’t work, then you won’t be able to stop your car or slow it down. This can result in a lot of road accidents and car crashes.

When checking for squealing sounds in your brakes, there are two sounds to watch out for: the soft squeals and the loud high-pitched ones.

If you hear a soft squeal, then you don’t need to worry too much because it’s most likely due to being wet.

However, you must check if your wheel stopped right at the moment that you applied your brake. If there is a short lag time, you might need to get your brake checked.

The second sound to watch out for is the high-pitched squealing sound. If you hear this while you apply your brake, then it most likely means that your brake pad needs a change.

Being worn out makes it squeal a lot and may result in damage to your car. To avoid any mishap, change your brake pad as soon as possible.

Worn Out Alternator Bearings

Although not as common as the previous 2 causes, the third probable cause is a faulty or worn out alternator bearing.

This is an issue that can’t really be solved on your own unless you’re really good with cars.

For this problem, you might have to go to the service station to get your alternator bearings checked. A professional mechanic can have this fixed for you.

How Do I Prevent These Noises?

Now that you know the three main causes of these noises, it’s easier for you to prevent them. All you have to do is maintain your car regularly and take care of it so there will be no problems.

Specifically, for squealing noises, here are some tips to help you avoid them:

Maintain your brakes.

First, you have to maintain your brakes well. Always check your brake fluid and ensure that there is always a sufficient level.

Also check whether the brake fluid needs to be changed. If it is thick and whitish, then it needs to be changed. Also, bleed your brake lines to let out all the air.

You need to pump your brakes and monitor the bleeder valve.

car being lifted by a jack

Lastly, you also need to regularly check the brake pads as this is where most of the squealing may come from.

Once you see that they are about to wear out, it’s best to change them right away. It is recommended that known brands are used for brake pads since the less known brands wear out faster.

Change your alternator bearing when necessary.

There’s nothing much that you can do about the alternator bearing aside from changing it. The only way to know if it’s about to fail or not is to check for noises.

If you start to hear even faint squealing noises from your alternator bearings, then you need to get them checked. If your mechanic suggests that you changed it, then have it replaced right away.

Make sure your belts are not worn out.

To check whether your belt is about to be worn out, it’s best to go through regular belt inspection. To do this, you have to check for four things:

  • Squealing noises when you turn on the engine
  • Squealing noises when the wheel is turned in one direction all the way
  • Grinding noises when the car is turned on
  • Slapping noises when the car is cruising

If you hear any of these while inspecting your car, check all your belts for wear and tear. Also, check for glazing or shininess on the belts.

This is a sign that the belts are loose.

If you see any of these signs, then you might want to change your belts. It’s recommended that you do this inspection once a month to be safe.


Although squealing noises are quite common when you own a car, they should never be overlooked.

These noises could be a sign that there are problems in some parts of the car.

In that case, it’s always best to look for the root causes of a scraping or squealing noise while driving if you hear them.

Better yet, inspect your car regularly to prevent hearing them while you’re on the road.

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