Why Is My Car Making That Noise?

Your car, truck or SUV has many systems with a lot of moving parts. When it’s new, everything works beautifully. But over time and many miles, parts can wear, fail or malfunction. When this happens, you may hear noises — squeaking, rattling, clunking, groaning and more — that indicate a problem.

Sounds coming from your car can be caused by a variety of issues. You may hear them when you apply the brakes, when accelerating or cruising down the road, when idling, or after shutting the car off.

Let’s break it down and try to identify the cause of the noise.

Noises when braking

When you press the brake pedal, your car should slow to a stop with no noise or shaking. But when things start to go wrong with your brakes, odds are you’ll hear it. Most of these noises are related to the brakes themselves, but there are other components that can make noise during braking.

Squeaking or squealing

A squeaking or squealing noise when you apply the brakes is most likely the sound of a brake pad wear indicator. These are built into your brake pads, and are designed to start making a noise when your pads need replacement. Call your mechanic and schedule an appointment for replacement pads.

If you hear a squeaking noise after you get new brakes, then it may be the sound of super-cheap, bargain-basement brake pads. They can make an awful noise, perform poorly and can damage other parts of your braking system. Buying cheap brakes is like buying a cheap parachute — the risk just isn’t worth it.

Grinding

If you hear a grinding sound when you press the brake pedal, you’ve waited too long. Your brake pads are totally gone. This is the sound of the metal backings of the brake pads grinding against your brake rotors, destroying them and putting you at risk of not being able to stop. Stop driving immediately, call your mechanic and get your brakes fixed. Be prepared, as this may get expensive.

Scraping

If your brakes are otherwise working well, this is probably just a stone that got stuck in one of your brakes. Rocks and debris can cause damage if they stay in place, so if the noise persists, call your mechanic, who should be able to remove the debris fairly easily.

Clunking or clicking

A clunking or clicking sound may indicate damaged or misaligned parts in your braking system, or possibly some bad components in your steering or suspension system. Call your mechanic — whatever the source, you need this problem fixed before your steering or braking goes haywire.

» MORE: Get an accurate estimate for your car repair

Noises when accelerating or cruising

When you accelerate, the entire drive system is under load. Cruising at a steady speed is a less stressful situation. Regardless, a variety of noises can arise from different locations and components as the vehicle is moving forward.

Pinging or knocking

Something is amiss in your engine. If you hear a pinging or knocking, odds are the fuel-and-air mixture in your car’s cylinders isn’t burning properly. A pinging sound under acceleration could also be a sign that you are using fuel with too low of an octane rating. You may have inadvertently put regular gas into a vehicle that requires premium.

Another possibility is that you have carbon deposits built up in your cylinders. You can try a higher octane fuel, or call your mechanic. The carbon deposits can be removed.

If you hear a knocking that’s low at idle and gets louder as you gain RPM, you may have either bad piston wrist pins or a worn crankshaft bearing. Both of these issues mean major, expensive engine repairs.

Rattling

Rattling noises can come from a ton of sources, and can be hard to pin down. We took an in-depth look previously, but here are some of the more common sources of rattles you might hear when driving:

• Low oil level
• Loose timing chain
• Bad water pump bearings
• Loose heat shielding
• Broken harmonic balancer
• Bad fan clutch
• Failing idler pulley
• Loose parts or items in your glove box, trunk or other storage areas

Clicking when turning

This noise will usually indicate that you have worn CV joints. Loose brake pads are another possibility. Talk to your mechanic.

Squealing from under the hood

This is most likely a sign of a loose or worn engine drive belt. A technician can take care of this pretty easily, but don’t wait to get this repaired. If your drive belt comes apart, it can damage a lot of other components and strand you.

Chirping

A repetitive chirping sound from the vicinity of a wheel often indicates a wheel bearing or axle bearing that is failing. Usually the noise will change with the speed of the vehicle. It may come and go at various speeds. Get this taken care of — if the bearing fails, it may cause the wheel to lock up or come loose from your car.

Chirping or squealing while accelerating is a also sign that you’ve got a belt or drive pulley going bad. You’ll want to get that checked out, too.

Roaring or loud exhaust

These noises likely mean you have an exhaust system problem. The solution could be as simple as tightening the connections between the system’s parts, or you could need a new muffler, or a complete new exhaust system.

Another possibility is that your exhaust manifold gasket has failed. When the engine is cold, this would sound like a ticking that gets louder when you accelerate. The sound may go away when the engine is warm, however.

Either of these problems need your attention right away — you don’t want poisonous gases seeping into your vehicle.

Grinding while shifting a manual transmission

If you hear grinding noises as you operate your stick shift, your clutch may need adjustment or be worn out. Your shift linkage might also need adjustment. The worst-case scenario is that you have internal transmission damage.

Ticking or clicking

These noises usually mean that your valve train is worn or needs an adjustment. Your mechanic can help.

Engine backfiring

A backfiring engine, either on acceleration or deceleration, points toward the need for an adjustment of you car’s ignition timing.

Get it diagnosed by a professional

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Noises when idling

You can hear a variety of noises when you start your car and let it idle. Some noises go away as your engine warms up and all the fluids start circulating. Others may persist, and require attention from your mechanic.

Rattling

This sound could lead you to a loose heat shield on your exhaust system, catalyst or turbocharger. It could also be a sign of a defective starter bendix, the part that disengages your starter after the engine has fired up.

Clicking

A clicking sound coming from the engine while it idles could be a sign of low oil pressure. This is a bad thing, and should be brought to your mechanic’s attention right away.

Hissing

Hissing noises while your engine is idling can indicate a few different problems. Your engine could be overheating, which is a serious issue. Your catalytic converter might be clogged, which may require a replacement. Or it may be something as simple as a vacuum leak, which can be fixed once you track it down.

Noises after shutting off your car

There are a few noises you might hear after you shut off your vehicle — but only a few. After all, it’s no longer running.

Metallic clicking

This is simply the sound of the contraction of hot engine and exhaust system parts as they cool down. Nothing to worry about.

Fan sound

This is the sound of your thermostatically controlled cooling fan. It can turn on after shutoff and run for a while to control the buildup of engine heat after the coolant and oil stop circulating. This is normal, and not something to be concerned about.

Hissing or sizzling

If you hear a hiss from under the hood immediately after turning off the ignition, it could be coolant leaking or oil dripping onto hot engine parts. Carefully see if you can find the source — but be careful not to burn yourself. If you suspect a leak, get it diagnosed by a professional.