Quick answer
A grinding noise often points to brakes or wheel bearings. A clicking noise when turning often points to CV joints or steering components. A humming noise that gets louder with speed may be tyres or a wheel bearing. A rattling noise on startup can be timing chain, exhaust or heat shield related.
If the noise is sudden, loud, getting worse, linked with braking or steering, or appears with warning lights, stop safely and get the vehicle checked.
Common car noises and what they may mean
Knocking noise
Can come from suspension, steering joints, engine mounts, engine faults or drivetrain wear.
Knocking when turning →Grinding noise
Often linked to brakes, wheel bearings or metal-on-metal contact.
Brakes grinding guide →Clicking noise
Clicking while turning is commonly linked to CV joints, driveshafts or steering parts.
Clicking when turning →Humming or droning
Often tyre noise or wheel bearing noise, especially if it gets louder with speed.
Wheel bearing noise →Squealing noise
Can be brakes, belts, pulleys or dry components depending on when it happens.
Brake warning signs →Whining noise
May relate to belts, alternator, power steering, gearbox, wheel bearings or turbo noises.
Whining when accelerating →Rattling noise
Can be exhaust heat shields, timing chain, loose trim, suspension or engine components.
Timing chain rattle →Blowing noise
A loud blowing sound can point to an exhaust leak or damaged exhaust section.
Exhaust blowing noise →When the noise happens matters
When accelerating
Can point to engine, gearbox, turbo, exhaust, driveshaft or mount issues.
Acceleration noise guide →When braking
Often brake pads, discs, calipers, wheel bearings or suspension movement.
Car shakes when braking →When turning
Often CV joints, steering components, suspension joints or wheel bearings.
Turning noise guide →At high speed
Often tyres, wheel balance, wheel bearings, loose undertrays or drivetrain noise.
High-speed vibration →At idle
Can be engine mounts, misfire, belts, pulleys, exhaust leaks or timing chain noise.
Car vibrates at idle →On startup
Can be belts, starter motor, timing chain, lifters, exhaust or battery-related strain.
Smoke on startup →Brake noises
Brake noises should be taken seriously because they affect stopping performance. Grinding, scraping or squealing while braking can mean worn pads, damaged discs, sticking calipers or debris caught near the brake.
- !Grinding when braking can mean pads are badly worn.
- !Squealing can be pad wear, brake dust, glazing or low-quality pads.
- !Scraping may be a stone, backing plate or brake hardware issue.
- !Vibration when braking may point to discs, pads or suspension movement.
Useful guides: brakes grinding when driving, brake warning signs and brake pad replacement cost UK.
Noises when turning
Noises when turning often come from the front end of the car. Clicking can point to CV joints, knocking can point to suspension or steering wear, and humming that changes through corners may suggest a wheel bearing.
Clicking
Often CV joint or driveshaft related, especially on full lock.
Knocking
Often suspension joints, bushes, drop links, mounts or steering components.
Humming
May point to a wheel bearing if the noise changes when cornering.
Useful guides: car clicking noise when turning, car knocking noise when turning and wheel bearing replacement cost UK.
Engine and exhaust noises
Engine noises can be harmless or serious depending on the sound. A brief rattle on startup may differ from a loud knock, misfire, blowing exhaust or metallic grinding noise.
- ✓Rattle on startup: timing chain, oil pressure, belt or heat shield issue.
- ✓Misfire sound: uneven running, shaking, popping or poor acceleration.
- ✓Blowing noise: exhaust leak or damaged exhaust joint.
- ✓Whining noise: belt, pulley, alternator, turbo or gearbox issue.
Useful guides: engine misfire symptoms, car exhaust blowing noise, timing chain rattle and alternator not charging signs.
When to stop driving because of a noise
- !Loud grinding, scraping or metallic noise.
- !Noise appears with brake warning, oil warning or overheating.
- !Steering feels loose, heavy or unpredictable.
- !The car pulls sharply, shakes badly or feels unstable.
- !There is smoke, burning smell or fluid leaking.
- !The noise gets worse very quickly.
If safety is in doubt, stop in a safe place and arrange recovery or professional inspection.
What to tell the garage
A clear description helps the garage find the fault faster. Try to note:
- ✓What the noise sounds like: knocking, grinding, clicking, humming, squealing or whining.
- ✓When it happens: accelerating, braking, turning, idling, cold start or high speed.
- ✓Where it seems to come from: front, rear, left, right, engine bay or underneath.
- ✓Whether warning lights, smells, smoke or vibration appear too.
- ✓Whether it started after repairs, pothole impact or a long journey.
Frequently asked questions
Why is my car making a grinding noise?
Grinding often points to brakes, wheel bearings or metal-on-metal contact. Grinding when braking should be checked urgently.
Why is my car making a clicking noise when turning?
Clicking when turning is commonly linked to CV joints, driveshafts, steering parts or suspension components.
Why does my car hum louder as I speed up?
A humming noise that gets louder with road speed is often tyre noise or a wheel bearing.
Why is my car rattling on startup?
Startup rattles can come from timing chains, belts, pulleys, heat shields, exhaust parts or oil pressure delays.
Can I keep driving with a strange car noise?
Only if the noise is mild and stable. Loud, sudden, worsening, grinding or safety-related noises should be checked quickly.
Can car noises fail an MOT?
The noise itself may not be the MOT failure item, but the cause can fail if it involves brakes, suspension, steering, tyres, exhaust or wheel bearings.