Many modern cars operate almost silently, so it’s a big deal when there’s an unexpected sound. Chirping, squealing, or ticking noises are generally not a great sign for your car, but they often only occur during specific actions, such as steering, braking, and accelerating.
Because the noises often indicate a problem, it’s usually best to take the vehicle in for service when you hear them. Some of the issues might be easy DIY fixes, but others need more in-depth repair work by a professional.
Here are 17 of the most frightening car sounds you might hear in your car and what they mean.
1. Clicking Noise and Car Won’t Start
If you turn the key or press the ignition button and hear a clicking sound instead of the car starting, it’s likely related to a dead or under-charged battery. The cause might be as simple as leaving the headlights on overnight, but there may be a slightly more serious problem with the alternator or related components.
Related: Reasons Your Car Won’t Start
2. Chirping, Squealing, or Squeaking Sounds
A high-pitched squealing or squeaking sound could mean that it’s time to replace the serpentine belt. It powers the vehicle’s accessories, including the water pump, and can wear over time, becoming loose. If it breaks, the vehicle can lose power steering and other vital systems, so it’s essential to have the belts checked if you hear a sound.
3. Gurgling or Bubbling Noise when Turning the Engine Off
If you hear a bubbling sound when you turn the car off, it’s most likely coming from the coolant expansion tank. These sounds don’t always indicate a serious problem, but it’s still a good idea to have the system inspected by a mechanic to be sure.
4. Sloshing Sound When Accelerating Or Starting the Vehicle
Liquid sloshing sounds when starting the car or accelerating could mean that air has gotten into the cooling system, which could be caused by a leak or a damaged engine head gasket. Unlike a slight gurgling sound, sloshing sounds usually come from more serious problems, so don’t ignore the warning signs.
5. Hissing or Sizzling Sound When the Car is Off
A hissing sound from under the hood when the car is off likely means that oil or coolant is leaking onto a hot part of the engine surface. That said, a hissing sound outside the car could mean that air is escaping from a punctured or damaged tire.
6. Knocking Sound While Driving
Rapid rattling sounds relate to detonation, which can happen when using a lower octane fuel than is recommended for the vehicle. Higher-octane fuels (i.e. premium gas) are generally required for turbocharged and high-performance vehicles, but if you’re unsure, the owner’s manual lists recommended fuel grades.
7. Popping Noise While Driving
If you hear a popping sound from under the hood, it could indicate a problem with the spark plugs or plug wires. It could also mean that the fuel filter is clogged and needs to be replaced. In some cases, a popping sound relates to the catalytic converter, which is part of your car’s exhaust system.
8. Tapping or Ticking Sounds While Driving
A tapping or ticking sound from under the hood may mean that the engine is low on oil. Even if you don’t see an oil warning light, pull over and check the oil. If the dipstick shows a sufficient oil level, there could be a problem with the engine valves or a lack of oil pressure.
9. Rattling Noise At Idle
If you hear a rattling sound that sounds almost like someone shaking a box of rocks under the hood when the car is idling, it could mean the catalytic converter is failing. Minor rattles may mean there’s a loose exhaust component or heat shield.
10. Whistling Noise at Highway Speeds
Your car isn’t airtight, but it’s designed to keep the outside out and the inside in. If you hear a whistling sound at highway speeds, it usually means that the car’s weatherstripping is damaged, creating noise as wind rushes over the area.
A whistling sound from under the hood may come from a leaky vacuum hose, which is a component of the vacuum system that powers many vehicle systems, including the brakes.
11. Grinding Noise When Changing Gears
A metallic grinding sound when changing gears with a manual transmission could mean the clutch is worn or needs replacement. That’s not all that serious on its own, but grinding sounds sometimes relate to more serious transmission issues that require immediate attention.
12. Screeching, Grinding, or Scraping Noises While Braking
Your car’s brakes aren’t silent, but they shouldn’t make a grinding or scraping sound when you press the pedal. Those sounds usually mean that one or more of the brake pads are worn and need to be replaced. Brake pads are a relatively simple repair. A clunking or knocking sound could indicate a more serious problem, so don’t ignore any unexpected noises while braking.
13. Clunking or Knocking Sounds on Rough Pavement
If you hear a clunking sound while driving over rough pavement, it could mean that there’s a problem with the suspension system. While it’s usually a worn shock absorber, other components may need attention, including the control arms and other parts.
14. Humming, Whirring, or Whining
Unfortunately, these sounds could come from a number of issues. Worn or damaged tires can make odd sounds. As the only part of your vehicle that touches the road, it’s important to address tire problems as they arise. If the tires are fine, the noises could relate to a more serious repair issue.
Wheel bearings can make humming or whirring sounds as they wear. Other potential sources of the noise could be a differential in need of lubrication, worn universal joints, and more. Those are serious components that perform essential functions in your vehicle, so don’t wait to have them checked out.
The transmission can also make similar sounds if there are issues, but if you only notice the sound when turning the steering wheel, it’s most likely related to the power steering fluid levels or the power steering pump. If that’s the problem, you may also notice that the steering wheel is more difficult to turn.
15. Buzzing Sound While Listening to Music
A buzzing sound coming from the stereo usually means one of the speakers has a loose connection or that a connector is coming loose on the head unit. If you hear the sound from all of the speakers simultaneously, the problem is likely coming from the head unit itself.
16. Rumbling Noise While Accelerating
Many people install aftermarket exhaust systems to achieve a beefy sound, but most unmodified vehicles are pretty quiet. If you start hearing a rumbling or humming sound while driving, it could mean there’s a hole or loose connection in the exhaust system.
17. Backfiring
Modern cars don’t backfire as much as older vehicles did, but it can still happen. If you hear what sounds like a gunshot coming from the engine or exhaust, it could mean the fuel system needs to be adjusted or that there’s a problem with the catalytic converter.
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