10 common car noises that could mean trouble!

January 19, 2021
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Learn about these 10 common car noises, what they could mean, and why you shouldn't ignore them


A car with an open hood exposing the engine

Sometimes, it seems as though our cars speak in their own language; a language filled with squeaks, squeals, roars, and bangs. To the untrained ear, these quickly become background noise until something out of the ordinary catches our attention. Even then, if you don't know what to listen for, it can be easy to let those sounds fade into the mix. 

But while comprehending this automotive language can be difficult, it's important to listen when your car speaks! They are often trying to tell us that something is wrong. That's why today, we'll give you a lesson in speaking car. Read on as we translate these 10 common car noises that could mean trouble!  

1. Squealing sound when you start your car


What you hear: Aloud squealing sound after starting the car that gradually fades. 

What it could mean: If you've ever heard a loud, screeching, squealing noise from the front of your car as you crank the ignition, you very well may have a serpentine belt that is failing, or nearing the end of its lifespan

The serpentine belt is a long rubber belt that runs around a number of pulleys and wheels in front of the engine. Depending on the specific make and model of your vehicle, the belt may be attached to the crankshaft as well as other systems, such as the AC compressor, the alternator, power steering system, and potentially other pumps. In other words, it is an essential component for many of your vehicle's systems. 

There are a number of different reasons your serpentine belt might make such an unpleasant noise when you start your car, but the most common cause is simply wear and tear. After time and use, the rubber belt becomes brittle, which can cause it to crack and slip, creating that shrill sound.

If your vehicle is making such a sound, it's important that you inspect the belt for sign of wear as soon as possible and replace it if needed. If left unattended for too long, the belt could fall off of the pulleys, incapacitating the systems that rely on it. In some cases, this could mean you're left without air conditioning, but it may also leave you stranded on the side of the road. 

2. Rattling noises when driving over a bump


What you hear: A rattling, vibrating, or squeaking sound coming from the wheels when you drive over a speed bump or pothole. 

What it could mean: There's a lot going on in the front end of your car. Apart from your engine, you have a suspension system with all sorts of parts that can rattle, especially if you have bad bushings. 

Bushings are rubber or synthetic components in the suspension system meant to cushion the various parts, reduce friction, and prevent vibrations. Like most rubber parts on a car, these can get brittle and break down over time. For this reason, bad bushings are often the culprit when it comes to these types of sounds. However, it may also be a bad sway bar link or possibly worn struts, shocks, or ball joints. 

It can be difficult to pinpoint a sound when you're in the car, so you may find it helpful to perform a bounce test at home when the vehicle is stationary. While parked, simply press down firmly on the front corner of the car and listen for the sound. This may not tell you exactly which bushing needs to be replaced, but it will tell you that your suspension is the source of the rattling. Ideally, this shouldn't produce any rattling or knocking, so if your test consistently produces noisy results, it's time to see the mechanic. 

3. Squeaking or whining when turning the steering wheel


What you hear: Squeaking, whining, or groaning when making a turn. 

What it could mean: If your vehicle was made within the last 50 years, chances are you have a power steering system. While some newer vehicles have implemented electric power steering, the most common variants are hydraulic systems. 

Like all hydraulic systems, power steering requires fluid to operate. When that fluid is low, or when the pump begins to fail, air can find its way into the lines, which can cause all sorts of strange noises. If you notice squeaking or whining when you turn, or if you find that it is difficult to turn, check your power steering fluid levels. You may simply need to top off the reservoir, but it could also be indicative of a leak. 

4. Low droning or humming noise


What you hear: A low droning noise that increases in volume when accelerating. 

What it could mean: A new set of tires not only gives you a smooth ride, it should be relatively quiet. When your tires are old or worn, they can begin to make a consistent droning sound, especially if they have worn unevenly. Alternatively, an underinflated tire can produce a similar sound.

If you hear such a sound, inspect your tires as soon as you can. You might simply need a little air, or you may have a leak. Your tires naturally wear down over time, but issues with your balance and alignment may cause the tread to degrade asymmetrically. In any case, routine tire maintenance is essential, and you'll likely need to visit the tire shop in the near future. 

5. Screeching or growling when you step on the brake pedal


What you hear: A high-pitched screeching sound, or a low, growling, grating sound when you step on the brakes. 

What it could mean: Your brakes can often be the source of all kinds of unnerving sounds, and they usually indicate that maintenance is required. The more high-pitch noises are often caused by built-in wear indicators in your brake pads, which means you may only need to replace the pads themselves. The lower, scraping sound could mean that your pads have almost completely worn away and the brake caliper is grinding against the rotor. Either way, you'll want to look into replacing your brakes as soon as possible. 

6. Loud bang from the rear of the car 


What you hear: A loud bang, similar to the sound of a firecracker or a gun. 

What it could mean: While the sound of a backfire is frightening, in most cases the explosive sound is a result of fuel burning at the wrong time (rather than some catastrophic explosion). Your engine may be running too rich (i.e. the fuel to air ratio is leaning heavily towards the fuel), the timing may be off, or there could be an issue with the spark plugs.
 
While this doesn't necessarily constitute an emergency, it means your engine isn't running at the highest efficiency, and if allowed to continue, it could damage your exhaust system. For that reason, it's recommended that you see a mechanic as soon as possible. 

7. Rumbling


What you hear: A low engine rumble accompanied by vibrations when idling. 

What it could mean: To function properly, your engine requires the correct mixture of fuel and air as well as a working spark plug to trigger the ignition. If any one of these elements is lacking, it may cause the rumbling vibrations you experience at low RPMs. 

This could be caused by dirty fuel injectors, which inhibits the fuel portion of the required mixture. Usually, adding a fuel injector cleaning solution to your gas tank can clear this up. The rumbling may also be caused by a lack of oxygen in the mix, which could mean your air filter is dirty and needs to be replaced. Alternatively, the oxygen sensor may be bad, resulting in the wrong fuel to oxygen mixture.

Finally, this could be caused by worn spark plugs. When your spark plugs fail to fire, or fire inconsistently, the combustion in your engine will be inconsistent, resulting in an uneven rumble. It is recommended that you replace your spark plugs every 30,000 to 50,000 miles, but consult your owner's manual for specific maintenance guidelines. 

8. Knocking or pinging from under the hood


What you hear: Knocking or pinging from the engine that increases with acceleration. 

What it could mean: While the particular sounds may vary based on your specific engine, they are generally referred to as "engine knock". Engine knock is typically tied to the improper detonation of the fuel inside the engine cylinders. 

When your engine is properly functioning, all of the fuel in a given cylinder combusts at the same time. When the burn is uneven, or when the fuel detonates at different times, it can cause this concussive sound. Sometimes, this is a result of using fuel with a low octane rating, but may also be indicative of damage somewhere in the engine. 

A more specific type of engine knock is known as "rod knock," which can occur when certain parts within your engine begin to wear, if you have a drop in oil pressure, or if your oil is incredibly dirty. 

Whatever the cause, engine knocking is something that needs to be addressed as quickly as possible. 

9. Sounds like an off-kilter washing machine


What you hear: A wobbling sound like a washing machine on a high spin cycle with loose change inside. 

What it could mean: Mechanics often compare this sound to that of a washing machine or clothes dryer for a good reason: the resemblance is uncanny. However, when you hear this sound while driving, the implications are much more severe. 

This sound is often caused by a loose lug nut spinning and banging around inside your hubcap, which means your wheel is not secure. If you hear this noise, pull over as soon as you safely can and tighten the loose nut or call roadside assistance to take you to a mechanic. 

10. Roaring sound during acceleration


What you hear: A roaring sound that increases as you accelerate, usually coming from beneath the driver's seat. 

What it could mean: Engines are noisy, but so is the process of venting the engine's exhaust. Usually, these hot gases are directed through a muffler, which greatly decreases the roaring sound. However, if there is a crack somewhere in the exhaust system, the gases escape before they can reach the muffler.

Beyond the sounds and vibrations, a damaged exhaust system could result in carbon monoxide leaking into the cabin. If you notice these sounds and symptoms, get to the mechanic right away. 

A man standing in front of a car with its hood open

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To learn how you can add this optional coverage to your Germania personal auto policy, or to learn more about our insurance products, call one of our trusted agents or request a quote online today!


Read more: If your car is making strange noises, a breakdown may soon follow. If your car breaks down on the road, remember these four critical steps

by Geoff Ullrich

About the Author

Geoff Ullrich is a writer and Content Marketing Specialist at Germania Insurance.