Become a Sound Hound
We hear noises constantly, but an unexpected sound can come as a real surprise – especially when it comes from your car. The problem with unexpected car noises is that they can spell trouble – and a potentially expensive trip to the garage. One really useful skill is to be able to identify these noises, and effectively describe them to your mechanic. It could save you both time and frustration.
A Question of Sound
Firstly, answer these questions, if safe to do so:
- Where is the noise? A passenger sitting in the back can really help with this
- When does the noise happen? E.g. when the car is moving? Braking? Turning? When changing gear? When hot or cold, wet or dry?
- Are there any other symptoms such as vibration through the steering or pedals or unusual odours?
- Is the noise ongoing, or intermittent?
Now you’ve identified the fundamentals of the noise, it’s time to think about what it might mean.
Beneath The Bonnet
Rubbery squeal or screeching — if this sound is intermittent, but getting worse, it could mean a worn or loose drive belt. It could also mean a problem with the air conditioning, power steering or water pump.
Growl/whine — this may indicate that one of the car’s accessories is failing. A groaning when you turn the car could also mean the power steering system needs to be checked, for example to ensure the correct fluid level or fluid condition.
Clatter — a metallic clatter coming from inside the engine could mean the engine’s valve train requires adjustment or maintenance, or that the engine oil needs checking/changing.
Hiss/whistle — this usually means a leak in a vacuum hose. Alternatively, a high-pitched whistle coming from the area of the alternator could suggest it requires maintenance.
Flapping — this could mean a drive belt is coming apart. Have it checked immediately.
Under The Car
Clunk — If you hear this when you change gear, it could be a problem with the gear box or the clutch. If you hear a clunk going into gear, especially if coupled with difficulty in gear selection, it could indicate an issue with your syncromesh. If this is heard on deceleration it may be linked to worn constant velocity (CV) joints.
Rattle — this usually indicates loose exhaust components, or a failed catalytic converter.
Whine — while the car is in motion this could indicate worn gears in the driveline, possibly in the differential. It may also mean the differential fluid needs to be topped-up or replaced.
Ticking - if you hear this when you turn off the engine, it’s probably just the exhaust system cooling off.
Tyres & Suspension
Knocking, clicking or rumble — if coming from the tyres or suspension when you’re above 40 mph it could mean a worn constant velocity (CV) joint. If you hear it at low speeds, especially when you’re turning, the cause could be a worn wheel bearing which could be about to fail.
Squeak — this sound from the suspension whenever you go over a bump usually means the rubber brushes that dampen vibration in the suspension system are worn or dry. It can also mean the shock absorbers or struts are in need of inspection.
Clicking — if the sound changes frequencies as you change speeds, chances are you have some foreign object either stuck in a tyre or possibly lodged between a wheel and brake or suspension component.
Howling — a tyre that “howls” at high speed could indicate a wheel alignment problem. Alternatively, it could mean a worn shock absorber or strut is allowing the wheel to move slightly. This may be accompanied by a vibration in the steering wheel.
Squeal— a common brake noise which frequently means that a metal wear indicator in the brake pad has been exposed, showing it is time to have the brake pads replaced. It can also mean a brake is dragging, which may indicate a need for maintenance.
Clunk — a clunk on braking usually means that one or more of the brake components is loose. Requires immediate attention.
Grinding — A rough grinding noise indicates metal-to-metal contact, which usually means the brake pad has been worn through. Again, have your brakes checked immediately. Alternatively, if the vehicle has not been driven for some time, it could be caused by rust on the brake discs, which may be removed over time during normal driving. This may also be accompanied by brake judder.
The information contained in this article are suggestions only and users should seek advice from a professional mechanic. Shell does not accept any responsibility or liability for the accuracy, content, completeness, legality, or reliability of the information contained on this article.
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