Your car starts making a new noise. What does it mean? How do you know if it’s serious? What should you do about it? This guide will help you learn if a car noise is harmless or potentially serious, when to see your mechanic, and what different car sounds mean.
Which Car Noises Signal Trouble?
Unfortunately, it can be difficult to identify exactly what’s going on inside your vehicle just by listening, but there are a few noises you should never ignore:
May Indicate a Serious Problem:
- Banging or thumping
Unlikely to Cause Serious Problems *
- Rattling that’s clearly coming from inside the cabin
- Squeaking when rolling windows up and down (as long as they close fully)
*Note: It’s a good idea to have a professional take a look any time your car suddenly makes an unusual noise, even if you think it’s probably harmless.
Now let’s get more specific. Keep reading to see a list of common car noises that may be a symptom of a larger problem. Here’s what each sound might mean and what you should do about it.
Banging or Thumping
Deep knocking noises are often a sign of serious trouble and even engine failure. Pull over and call for road service to be safe.
- A loud knocking in your engine could be a worn out rod bearing, which can destroy your engine. This can happen to vehicles with poor engine maintenance or very high mileage.
- Clunking when braking may mean a brake caliper has been damaged or improperly mounted.
- A knocking or rapping sound could also mean your vehicle has low or dirty oil that needs to be replaced.
Many things can cause clicking or rattling. In any case, it’s probably time for a maintenance check-up. Common causes of clicking include the following:
- Clicking, tapping, or rattling when your engine idles might mean your engine oil is low, which is easily fixed with an oil change.
- Rattling from the engine bay can indicate a damaged heat shield.
- Rattling from underneath the vehicle may be caused by a loose exhaust system or loose brake pads.
- Other mysterious clicking sounds could signal faulty ignition equipment, a loose spark plug, an old battery, low air conditioning fluid, or loose or worn belts.
Grinding usually happens when two auto parts rub together in a way they’re not supposed to, which means it could be almost anything. Here are a few things grinding could mean for your vehicle:
- General grinding sounds may indicate a broken power steering pump, water pump, or alternator.
- Grinding when braking might mean worn brake pads, which should be fixed right away.
- Grinding that gets worse when you drive faster could be a faulty wheel bearing — a serious safety issue.
Squealing is a pretty common car noise that often gets ignored. But squealing isn’t just annoying, it can indicate a number of serious issues. Here are a few:
- Squealing when you step on the brake means your brake pads may be worn. If they are, they should be replaced immediately.
- A high-pitched squeal which stops when the engine is off could mean your serpentine belt needs to be readjusted or replaced.
- Squealing when accelerating is another sign your serpentine belt may be loose or damaged. If the belt is frayed, cracked, or glazed, it definitely needs to be replaced.
- Persistent whining can indicate transmission wear.
- Roaring upon ignition or acceleration can mean the exhaust system is damaged.