Why Is My Car Making a Scraping Noise?

A metal scraping noise while driving is not only shrill, it's also annoying. More importantly, it's potentially dangerous to your car and your safety.

This diagnostic guide will help you identify what's causing the scraping noise and access relevant repairs, putting your mind at ease and getting you back out on the road.

Scraping noise from the wheel while driving

If you can hear a scrape along your wheel, check for debris in and around your brakes by carrying out a visual inspection. Upon finding anything that shouldn't be there, try your best to remove it. Foreign objects are most likely wedged under a brake pad or by the wheel bearing.

An easy way to do this if you cannot remove the debris by hand is to drive gently in reverse, release the brake, and then repeat to remove anything stuck between the calliper and the disc.

Scraping noise while accelerating

A scraping noise while accelerating may result from several things.

1. Worn wheel bearing

Wheel bearings connect the wheel and the axle - you can learn more about how they work in this guide. They are hard-wearing and can last between 60,000 and 100,000 miles. You may notice grinding or scraping noises when they wear out, especially when accelerating and turning.

How much does it cost to fix a worn wheel bearing?

On average, it costs £202.37 for a wheel bearing replacement on FixMyCar.

2. Automatic transmission problems

Scraping when you accelerate in an automatic car indicates there may be a problem with the transmission. Specifically, the gears could be worn, which happens naturally over time but can also be accelerated by low transmission fluid.

The first thing to do is check the transmission fluid reservoir. Top it up as needed - this may fix the scraping noise - and see if you can spot any leaks. Leaking fluid is a sign you should stop driving and book a repair as soon as possible.

Check out this guide for more information on identifying and fixing leaks.

If there's enough fluid in the reservoir and no visible leaks, it may be the case that one or more transmission components are worn and need replacing.

How much does it cost to fix an automatic transmission problem?

The average price of an automatic transmission diagnostic test is £169.55 when you book through FixMyCar.

Scraping noise while driving

The following issues could be to blame.

1. Worn alternator

The alternator converts chemical energy into electrical energy, charging the battery and other components as you drive. It lasts about seven years - between 80,000 and 150,000 miles - though it can fail prematurely.

A scraping noise often indicates that the alternator's bearings are worn out or dirty. Other signs of a worn alternator include:

• Dim or bright lights

• Trouble starting the engine

• Dead battery

• Dashboard warning light

• Frequent stalling

How much does it cost to fix an alternator?

The average price of an alternator repair booked through FixMyCar is £533.64. It may cost less to replace a bearing, so it's worth shopping around for quotes.

2. Damaged water pump

The water pump takes coolant from a car's radiator, moving it through the motor and back to the radiator to keep the engine cool. A bad bearing could be to blame for the scraping noise or the water pump pulley. If this is the case, you may also notice leaking coolant under the pump.

It's essential to have the issue diagnosed quickly since a malfunctioning cooling system can cause engine damage.

How much does it cost to fix a damaged water pump?

The average cost of a water pump repair on FixMyCar is £310.45.

3. Failing AC compressor

The compressor is responsible for powering your car's air conditioning unit. It places the refrigerant under extremely high pressure and pumps it into the condenser, where it transforms from gas into a liquid.

The compressor must be in good shape for the AC system to work effectively. It uses a sealed bearing to rotate, and when this bearing wears out, there will be obvious signs.

You'll first notice that your aircon stops blowing cold air. A leaking or worn-out bearing will create a scraping or squeaking sound, while a seized bearing is more likely to make a grinding noise.

How much does it cost to fix your aircon?

The average price of an aircon compressor repair is £404.95.

4. CV joint issue

Constant velocity (CV) joints are ball-and-socket mechanisms connecting the axles to the front wheels. They aid steering, driving and braking, making them crucial components. A typical front-wheel-drive car has two CV joints on each axle, one connected to the wheel and the other to the transmission. They must be in top condition and capable of handling the vehicle's total weight.

Find out how a car's steering works.

Like our joints rely on fluid to protect them, so do CV joints. They are packed with grease and sealed inside rubber boots. However, when they fail, they can no longer transfer power from the engine to the wheels, which is dangerous.

How much does it cost to fix a CV joint?

If you suspect your CV joints are worn, contact a mechanic immediately and avoid driving your vehicle until it has been inspected. The average price of a CV joint repair is £190.68 when you book through FixMyCar.

Scraping noise while braking

1. Worn brake pads

A scraping noise from your brakes may indicate that your brake pads are worn out - read about how long they should last here. When they wear out, the exposed metal rubs against the metal of the rotor, making an unpleasant noise. Your pads need replacing to avoid more extensive damage.

Another possibility is that the brake pads are not worn but are of poor quality. Defects such as metal chunks in the rubber pad, through poor manufacturing, can cause scraping from the get-go. Fitting good quality brake pads will last a lot longer and cost less in the long run.

This guide discusses five brake problems you shouldn't ignore.

How much does it cost to fix worn brake pads?

Replacing the front and rear pads costs £252.60 on average.

If you have any other issues with your car that you'd like to try to diagnose yourself, check out our guide on self-diagnosing car problems. The more you know about how your car works, the better.

If you found this guide helpful, you might also like:

• Diagnose strange noises in your car & find a fix

• Diagnose car problems & find the right fix

• Why does my car make a clicking noise?

• Why is my car squeaking?

• Why is my car making a hissing noise?

• Why is my car making a thumping noise?

• Why is my car vibrating?

• Why is my car shaking?

• Why is my car making a grinding noise?

• Why is my car making a clunking noise?

• How much does it cost to repair brakes?