Why is my car making a grinding noise?

Ellie Dyer-Brown, 2 years ago

5 min read

  • Guide
  • Advice
  • why
  • warning
Grinding noise blog

WhoCanFixMyCar explains why your car might be making a grinding noise and what you can do to address the problem

Sometimes it feels like cars have a language of their own. If you can work out the meaning behind the unusual noises they make, it can help you diagnose problems early.

Which is why in this particular advice guide, we’re going to discuss grinding noises and some of the most common things that cause them.

Damaged water pump

If the sound definitely isn’t coming from your brakes, and it happens while the engine is running, you may have a problem with your water pump. Grinding noises from the water pump usually indicate worn bearings. 

While it’s possible to replace the bearings, it’s likely that the seals will be worn as well, so the whole water pump is usually replaced as a precaution. This is a fairly inexpensive job that you shouldn’t put off - a damaged water pump could cause your engine to overheat, resulting in more damage and a more expensive repair bill.

The current average price for a replacement water pump across all makes and models on WhoCanFixMyCar is £243.02.

Worn alternator


The alternator is responsible for charging the battery and providing the vehicle with electrical power while the engine is running. As they age, the bearings inside the alternator become worn, and the pulley becomes slack enough that it can move side to side while spinning. This is what causes the grinding noise.

While alternators can be expensive to replace, it is a relatively easy job to complete which will reduce labour costs. You shouldn’t put off getting your alternator replaced if it’s making a grinding noise because it plays such an important part in the car’s functioning. 

ManufacturerAverage Cost of Alternator

Air conditioning compressors

If you only hear a grinding sound when your AC is on, this probably indicates a problem with the compressor. The compressor sends refrigerant through the air conditioner’s lines and allows a heat exchange.

If the compressor wears down, the pistons will start making an unpleasant grinding sound. Getting your AC repaired isn’t urgent as it won’t affect the overall functionality of your car, but if the summer months are approaching you might want to consider getting your compressor replaced.

Worn clutch

Clutch Replacement

A grinding sound that happens when you change gears indicates a problem with your clutch. 

Simply put, the purpose of the clutch is to separate the engine from the wheels, allowing you to change gears. It consists of the clutch plate, pressure plate and flywheel. If there is a problem with one or all of these components, you’re likely to experience a number of symptoms as well as a grinding noise:

  • Squeaking or grumbling sound when pressed.

  • Difficulty changing gear.

  • Slipping’ clutch, resulting in a brief loss of acceleration.

  • Spongy, sticking or vibrating clutch pedal.

Clutch repairs have a reputation for being expensive, but really the cost depends on the nature of the problem and the make/model of your car. To avoid causing more damage, you should take your car to a garage as soon as possible if you suspect your clutch might need repairing or replacing.

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