Why Is My Car Making a Rattling Noise?

Ellie Dyer-Brown, 3 months ago

5 min read

  • Advice
  • Maintenance
  • why
  • warning
Rattling noise blog

If your car is making a rattling sound, it’s more than likely that something is wrong with your vehicle.

Nobody wants to end up with an expensive repair bill, but getting problems fixed as soon as they happen can save you lots of time, money and stress in the long run. That’s why it’s essential not to ignore rattling noises (even if you really want to).

This guide takes you through the most common causes of rattling so you can decide whether to tackle the problem yourself or leave it to a mechanic.

Guide Contents:

What does it mean if my car makes a rattling noise?

Rattling noise under my car

Rattling noise under my car bonnet

Rattling noise while accelerating

Rattling noise from inside car

What does it mean if my car makes a rattling noise?

If your car is making an unusual rattling noise, there could be several causes. In most cases, it will have something to do with a loose part or component. The easiest way to determine what is causing the noise is to pinpoint which area of the car it's coming from.

Rattling noise under my car

Loose exhaust system

If you hear rattling from under the back end of your car, it’s a sign that the exhaust system has become misaligned. Alternatively, the silencer, positioned right by the exhaust pipe, could have come loose. Both problems can easily be fixed and shouldn’t cost too much money.

The average price of an exhaust repair booked through WhoCanFixMyCar is £112.67.

Mechanic checking car exhaust

Faulty suspension

If you hear rattling while going over potholes or speed bumps, your suspension is likely at fault. Issues could come from one of the many components of the suspension system, including control arms, ball joints, tie rods, strut mounts or the sway bar link.

Suspension repairs

Unless you have decent mechanical knowledge, the best course of action is to take your car to a garage to have the suspension system checked by a professional.

Suspension repairs cost £127.40 on average when booked through WhoCanFixMyCar.

Rattling noise under my car bonnet

Low engine oil

The first thing to check if you can hear a rattling noise under your car’s bonnet is the engine oil level. When there isn’t enough oil circulating through your engine, it can cause rattling as different parts rub together without lubrication. Top up your oil as needed to avoid causing severe damage, and don't forget to check for a leak that may have caused the low fluid level.

Mechanic changing engine oil and fluids

Cracked or broken serpentine belt

The serpentine belt drives your car’s alternator, AC compressor and water pump. If you’re not sure how to tell the difference between a serpentine belt and a timing belt, the latter can’t usually be seen because it’s hidden under protective covers. 

Close up of serpentine belt and pulleys

Driving your car with a faulty or broken serpentine belt can cause the engine to overheat, so the best thing you can do is open up the bonnet to have a look and decide whether you can take the car to a mechanic yourself or if it will need towing.

Rattling noise when accelerating

Broken catalytic converter

Your catalytic converter consists of small, honeycomb-shaped pieces that can cause a rattling noise when broken. If this is the case, the rattling will be loudest when you start the engine and worsen over time. Unfortunately, catalytic converters are often expensive to replace, but this isn’t a job you can put off.

Catalytic converter being removed from old vehicle.

Rattling noise inside car

The good news is that any interior rattling is likely down to something small and can probably be fixed by you. Check the interior for any objects that are loose and could be causing the rattling. The glove box is an excellent place to start. You should also check the in-door storage pockets. If you can’t find an obvious noise source, you might need to take your car to a garage where they can look for any underlying causes.

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

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