Common Noises Your Car Makes and What They Usually Mean

Cars make plenty of normal sounds. The engine starts, the tires roll across the pavement, the air conditioning fan runs, and the transmission changes gears. When a new squeak, grinding sound, knock, rattle, or hum suddenly appears, however, your vehicle may be trying to tell you something.

Some unusual car noises point to relatively simple maintenance needs. Others can indicate problems with the brakes, suspension, engine, exhaust system, wheel bearings, or other important components. Knowing what different sounds can mean can help you recognize when it is time to schedule an inspection before a small issue becomes a larger repair.

Below are some of the most common noises drivers hear and what they usually mean.

Squealing or Squeaking When You Brake

A high-pitched squeal when applying the brakes is one of the most recognizable automotive noises.

In many cases, squealing brakes are caused by worn brake pads. Many brake pads include wear indicators designed to produce a noticeable sound as the friction material gets low. This alerts the driver that it may be time for brake service.

Brake squealing can also be related to:

• Brake dust

• Moisture on the brake components

• Glazed brake pads or rotors

• Certain brake pad materials

• Uneven brake wear

An occasional brief squeak, particularly after your vehicle has been sitting overnight, does not always indicate a serious problem. Persistent squealing should be inspected, especially if braking performance feels different.

Grinding When Braking

Grinding is generally more concerning than squealing.

A grinding sound when you apply the brakes may mean the brake pads have worn down significantly enough that metal components are contacting the brake rotors.

Continuing to drive with severely worn brake pads can damage the rotors and potentially increase the amount of repair work required.

Grinding can also indicate other brake component problems, so it is best to have the braking system inspected promptly.

At Lexpert Auto Care, brake services include brake inspections, brake pad and rotor replacement, brake fluid service, caliper service, and diagnosis of brake noise and vibration.

Clicking When Turning

If you hear a repetitive clicking or popping noise while making turns, especially sharper turns, the sound may be coming from a CV joint.

CV joints transfer power from the transmission to the wheels while allowing the suspension and steering system to move. A damaged CV boot can allow grease to escape and dirt or debris to enter the joint, eventually causing wear.

A worn outer CV joint often produces a rhythmic clicking sound that becomes more noticeable while accelerating through a turn.

Because CV joint problems can worsen over time, persistent clicking during turns should be inspected.

Clunking Over Bumps

A clunk or knock while driving over speed bumps, potholes, or uneven pavement often points toward the suspension or steering system.

Possible causes include worn:

• Sway bar links

• Control arm bushings

• Ball joints

• Struts

• Shocks

• Tie rods

• Other suspension components

Your suspension does much more than make the ride comfortable. It also plays an important role in tire contact, steering response, handling, and vehicle stability.

If your vehicle begins clunking over bumps—particularly if you also notice loose steering, uneven tire wear, excessive bouncing, or changes in handling—an inspection can help determine which component is responsible.

Humming or Growling That Gets Louder With Speed

A humming, growling, or rumbling sound that becomes more noticeable as vehicle speed increases may indicate a wheel or tire problem.

Possible causes include:

• Worn wheel bearings

• Uneven tire wear

• Tire damage

• Improper tire balance

• Certain alignment-related tire wear patterns

A failing wheel bearing frequently creates a growling or humming sound that changes with vehicle speed and may become louder when the vehicle turns in a particular direction.

Because tire and wheel bearing noises can sound similar from inside the vehicle, a professional inspection is usually the best way to identify the actual source.

Rattling Under the Car

If you hear a metallic rattle underneath your vehicle, particularly while accelerating or driving over uneven roads, the exhaust system is one possible source.

The noise could come from:

• A loose heat shield

• Exhaust brackets or hangers

• A loose exhaust component

• Muffler or resonator damage

• Internal catalytic converter damage

Exhaust rattles can sometimes be relatively straightforward repairs, but they should not be ignored. Damage to the exhaust system can also cause excessive noise, exhaust leaks, emissions problems, or other drivability concerns.

Roaring or Excessively Loud Exhaust

If your vehicle suddenly sounds much louder than usual, an exhaust leak may be responsible.

An exhaust leak can develop around exhaust pipes, gaskets, the muffler, resonator, catalytic converter, or other connections.

Depending on the location, you might hear:

• Roaring

• Hissing

• Tapping

• Rumbling

You may also notice exhaust odors or a change in how the vehicle runs.

Because the exhaust system is responsible for safely directing exhaust gases away from the passenger compartment, unusual exhaust noises deserve attention.

Knocking or Tapping From the Engine

Knocking, tapping, or ticking noises coming from the engine can have several possible causes, ranging from relatively minor issues to problems requiring immediate attention.

Potential sources can include:

• Low engine oil

• Incorrect oil level or pressure

• Valve train components

• Timing components

• Internal engine wear

• Combustion-related problems

Some engines naturally produce more mechanical noise than others, particularly during a cold start. What matters most is whether the sound is new, unusually loud, persistent, or accompanied by other symptoms.

If your engine develops a noticeable knocking or tapping sound, checking the oil level is a good first step. If the noise remains or the oil warning light appears, have the vehicle inspected.

Squealing From Under the Hood

A squealing or chirping sound coming from the engine compartment may be related to the accessory drive belt or one of the components driven by it.

Possible causes include:

• A worn serpentine belt

• Incorrect belt tension

• A worn tensioner

• Pulley bearing problems

• Alternator issues

• A/C compressor-related problems

You may notice the sound primarily when starting the vehicle, accelerating, turning on the air conditioning, or turning the steering wheel, depending on the vehicle and the source of the problem.

A worn belt should be addressed before it fails and leaves you stranded.

Hissing From Under the Hood

Hissing usually indicates that air, vapor, or fluid is escaping somewhere.

Depending on when and where you hear it, possible causes include:

• Vacuum leaks

• Cooling system leaks

• Radiator or coolant hose leaks

• Intake system leaks

• A/C system issues

If you hear hissing along with rising engine temperature, steam, or a coolant warning, safely stop driving and allow the vehicle to cool. Never remove a radiator or cooling system cap while the system is hot and pressurized.

Cooling system problems can quickly lead to engine overheating, so they should be diagnosed promptly.

Whining While Turning the Steering Wheel

On vehicles equipped with hydraulic power steering, a whining or groaning sound while turning can sometimes indicate low power steering fluid or a problem with the power steering pump.

Other steering components can produce noises as well.

If the sound is accompanied by steering that suddenly feels heavy, inconsistent, or difficult to turn, the vehicle should be inspected.

Modern vehicles use several different types of steering systems, including electric power steering, so the exact cause depends on the specific vehicle.

Clicking When You Try to Start the Car

You turn the key or press the start button and hear clicking instead of the engine starting.

Often, the first thing to investigate is the battery or starting system.

Possible causes include:

• A weak or discharged battery

• Poor battery connections

• Starter problems

• Charging system problems

Rapid repeated clicking frequently occurs when the battery does not have enough power to properly engage the starter.

One solid click without the engine turning may point toward a different starting-system problem.

Battery, starter, and charging system testing can help determine whether you simply need a battery or whether another electrical component is responsible.

Rattling or Knocking When Accelerating

A noise that appears specifically during acceleration can have several possible sources.

Depending on the vehicle and type of sound, possibilities include:

• Engine-related problems

• Exhaust components

• Worn motor mounts

• Driveline components

• Loose shields or brackets

• Combustion-related issues

The conditions under which the noise occurs provide important diagnostic clues. Pay attention to whether it happens only during hard acceleration, at a particular engine speed, when the engine is cold, or after the vehicle reaches operating temperature.

These details can help a technician narrow down the cause.

Squeaking or Chirping That Changes With Vehicle Speed

A repeating squeak or chirp that gets faster as your vehicle speeds up often suggests that the sound is related to something rotating with the wheels.

Possible sources include:

• Brake components

• Tires

• Wheel bearings

• Axles

• Other rotating components

The key distinction is whether the sound changes with vehicle speed or engine speed.

If the frequency follows the speed of the vehicle rather than the engine RPM, technicians will typically begin looking at components associated with the wheels, tires, brakes, and driveline.

Why You Shouldn't Ignore a New Car Noise

A strange noise does not automatically mean your vehicle needs an expensive repair.

Sometimes the problem is relatively simple.

The challenge is that many vehicle problems become more expensive when allowed to progress.

For example, replacing worn brake pads early may prevent unnecessary rotor damage. Identifying a damaged suspension component may prevent additional tire wear. Repairing a small coolant leak can help avoid an overheating event.

Having an unfamiliar noise diagnosed early gives you the opportunity to understand what is happening and decide how to address it before the problem potentially becomes more serious.

Pay Attention to When the Noise Happens

When you bring your vehicle in for diagnosis, one of the most useful things you can tell your technician is exactly when the noise occurs.

Try to notice:

• Does it happen when starting the engine?

• Does it occur only when the engine is cold?

• Does it change as engine RPM increases?

• Does it get louder as vehicle speed increases?

• Does it happen while braking?

• Does it happen while accelerating?

• Does it occur when turning?

• Does it happen when driving over bumps?

• Does the noise disappear after the vehicle warms up?

• Is there a warning light on the dashboard?

You do not need to know what the problem is. That's what the diagnostic process is for.

Simply describing the sound and when you hear it can give your technician valuable information.

When Should You Stop Driving?

Some unusual sounds can wait for a scheduled inspection, while others warrant more immediate attention.

Stop driving when it is safe to do so if a strange noise is accompanied by symptoms such as:

• An oil pressure warning light

• Severe overheating

• Smoke or steam

• Loss of braking ability

• Significant steering problems

• Major loss of engine power

• Strong burning or fuel odors

• Severe grinding or knocking

• A vehicle that suddenly becomes difficult to control

When you are unsure whether a vehicle is safe to continue driving, it is better to have the situation evaluated than risk causing additional damage or creating a safety problem.

Strange Car Noise? Let Lexpert Auto Care Take a Look

You do not have to diagnose your car based on the sound alone.

Lexpert Auto Care provides professional vehicle diagnostics and repair for drivers throughout Mesa and Arizona's East Valley. Our services include brake repair, suspension and steering service, tires and alignment, engine diagnostics, cooling system repair, exhaust and emissions service, electrical diagnostics, transmission and driveline service, and routine vehicle maintenance.

We specialize in Lexus and Toyota vehicles and also service a variety of Japanese vehicles and other makes.

If your car has developed a squeak, rattle, knock, grind, hum, click, or another sound you have never heard before, bring it in and let an experienced technician identify what is actually causing it.

Lexpert Auto Care is located at 7931 East Pecos Road, Suite 156, Mesa, AZ 85212.

Call (480) 390-0612 or schedule an appointment with Lexpert Auto Care today.