Heard something go bump on the road? Your vehicle may be trying to warn you

Scary Vehicle Noises Explained

Most drivers know the usual sounds their vehicle makes.

You get used to the engine note, tyre noise and the odd creak or rattle that comes with everyday driving. So when a new clunk, grind or rumble appears, it tends to get your attention.

That does not mean the first sound you hear will tell you exactly what is wrong.

The same noise can have several possible causes, which is why it helps to notice when it happens, where it seems to come from and whether anything else has changed at the same time.

A current MOT certificate also does not guarantee that a vehicle will remain safe to drive until its next test.

If a new noise appears and you cannot explain it, it is worth getting the vehicle checked.

A clunk when pulling away or changing gear

A heavy clunk as you move off or change gear can make the gearbox seem like the obvious place to start.

It may not be the only possibility.

Worn engine or gearbox mounts can allow more movement than normal when power is applied. The clutch or transmission may also need attention.

Try to notice exactly when the sound appears.

Does it happen only when pulling away? In every gear? When lifting off the accelerator?

If you also notice juddering, difficulty selecting gears or a change in the way the vehicle drives, make a note of that too.

Those extra details can help a garage narrow down the cause more quickly.

A knock over potholes or speed bumps

If the noise appears mainly on rough roads, the suspension is one area a mechanic may inspect.

Worn suspension parts or a damaged spring can create knocks, clunks and rattles.

A loose exhaust can make a very similar sound, which is why noises from underneath a vehicle are often difficult to identify from the driver’s seat.

For vans, it can be useful to notice whether the noise changes when the vehicle is carrying a load.

That can help a mechanic reproduce the problem, but it does not necessarily mean the load is causing it.

A metallic rattle from underneath

A metallic rattle often sounds as though something underneath the vehicle has come loose.

Sometimes that is exactly what has happened.

An exhaust component or another part may be vibrating against the underside of the vehicle.

The AA also notes that a failing catalytic converter can make a noise similar to a loose exhaust.

Because sound can travel through the body of a car or van, the location can be misleading.

A proper inspection is the best way to trace it.

A rumble that increases with road speed

Not every warning sound is a knock or rattle.

A wheel bearing issue can sound more like a hum or rumble that becomes louder as the vehicle speeds up.

Tyres and other wheel-related faults can also create unfamiliar noises.

If the sound clearly changes with speed, tell the garage.

That pattern can often be more useful than trying to identify the faulty part yourself.

Scraping, clicking or grinding when braking

Any new noise during braking deserves attention.

Scraping, clicking or grinding may be linked to worn brake components or something caught close to a brake disc.

If a vehicle has been parked for a while, surface rust on the discs can sometimes create temporary noise as well.

A knock while turning may point towards steering or suspension components.

Because braking, steering and suspension all affect how the vehicle stops and handles, changes in these areas should be checked promptly.

If the noise is severe or the vehicle feels different under braking or steering, stop somewhere safe and seek professional advice before continuing.

What about motorbikes?

Motorbike noises need the same care.

A small mechanical change can sometimes be easier to feel as well as hear.

Pay attention to whether the sound appears during acceleration, braking or while riding over bumps.

Areas a mechanic may need to inspect include the chain and sprockets, suspension, wheel bearings and exhaust.

An excessively loose or worn chain or sprocket can be treated as a serious MOT defect.

If the bike begins to feel different under braking, steering or acceleration, have it checked rather than relying on the noise alone.

What should you tell the garage?

Before booking the vehicle in, make a quick note of what you have noticed.

Useful details include:

• when the noise happens

• where it seems to come from

• whether it changes with speed

• whether it appears during braking, steering or gear changes

• whether it is getting louder or more frequent

   whether the vehicle feels different to drive

That information can help a mechanic reproduce the issue and find the cause more quickly.

Only an inspection can confirm what is wrong and whether the vehicle is safe to use.

So, if something starts going bump on the road this Halloween, there is probably a mechanical explanation rather than anything supernatural.

But a new clunk, rattle or grind is still your vehicle’s way of telling you that something has changed.

Better to get it checked before the noise becomes a bigger problem.

Happy Halloween!