Why is my car making a clunking noise?

Ellie Dyer-Brown, 4 months ago

5 min read

  • Advice
  • Maintenance
  • Repair
  • why
  • warning
Clunking noise blog

WhoCanFixMyCar looks at some of the reasons why your car might be making a clunking noise

It can be tempting to ignore any unusual noises coming from your car, but the truth is that these noises often indicate an underlying problem, and the sooner you get them checked out by a professional, the less money you are likely to pay for repairs.

Like banging or hissing, clunking is one of the most common noises you should listen out for in your car. We’ve created this handy ‘diagnose it’ guide to help you work out what might be going wrong, so you can be more informed when taking your car to a garage for repairs.


Clunking noise when I start my car

Clunking noise while driving my car

Clunking noise while braking

My car makes a clunking noise when it starts

A car that makes a clunking noise when you start the engine usually indicates either a starter failure or broken teeth on your transmission’s flex plate.

Starter motor replacement is not too big a job, though it is likely to take a mechanic several hours to complete. A faulty or failing starter will get worse with time, and could result in smoke coming from your car or an engine that will no longer crank. You should get it checked by a mechanic as soon as you can.

A transmission replacement, on the other hand, is a much bigger and more costly job. Transmission is another name for your car’s gearbox - without this key component, there would be no way to turn the engine’s power into something that can be used for movement. 

There are a few different causes of a clunking sound within the transmission system:

Low or old transmission fluid

Thankfully this one is an easy fix. You can check the fluid level and quality yourself. It should be red or dark pink and translucent. Brown, black or cloudy fluid should be replaced.

Internal components

Your transmission contains a large number of bearings, gears and springs which can go wrong.

Engine and transmission mounts

If these are broken, the engine and transmission will move when you shift gear, causing a clunking sound.

Sensor issues

The transmission of new vehicles is often controlled by computerised sensors. If they send information that is wrong or at the wrong speed, a clunking can result.

My car makes a clunking noise while driving

If you hear a clunking noise that is especially prominent when you drive over potholes or speed bumps, you probably have a problem with your shock absorbers or your suspension.

Continuing to drive with a broken or faulty shock absorber is a bad idea for the health of your car. The chances are, it will cause your tyres to wear unevenly, and your brake time will also be significantly reduced. 

Some other common symptoms of worn shock absorbers are: nose-diving whilst braking, fluid leaks and suspension/steering vibrations. If you notice any of these symptoms, you should take your car to a garage to prevent further damage. 

The best way to avoid shock absorber problems in the future is to stick to smooth roads as much as possible and, when you have to tackle an uneven or bumpy road, take it slowly.

Hearing a clunk when you drive over a bump could also indicate excessive clearance in a suspension joint due to wear. Your suspension system has a number of parts which become worn over time, and as a result, they perform less efficiently, putting your car at risk of damage. 

If you think your suspension might need fixing, you can quotes within minutes from the best garages in your area through WhoCanFixMyCar.

My car makes a clunking noise while braking

A clunking noise when the brakes are used typically suggests wear and damage to various parts. It can be caused by a number of things from a seized brake caliper or an extremely loose wheel bearing to worn out ball joints or steering components.

Brakes are incredibly important when it comes to your safety and the safety of your passengers, so if you suspect yours aren’t working as they should, please don’t delay - take your car to a professional as soon as you can.

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