7 months ago

Decoding Messages from a Car – What do Different Car Noises Mean?

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The noises coming from a car are not only irritating, but they can also indicate some serious issues in your vehicle that need to be fixed as soon as possible. 

There are a lot of factors that can lead to unusual noises in your car. Most of the time, it is not easy for the average driver to effectively diagnose what’s causing them. From worn-out brakes to a jammed serpentine belt – these weird sounds can mean anything.

In this post, we will try to decipher some of the most common noises that cars make. We will also be discussing some solutions to tackle these noises and their underlying causes.

The unusual noises in a car can broadly be classified into two categories: those arising from the engine bay and those originating in your wheels.

Let’s discuss both of them in detail.

A. Noises from the Engine Bay

Here are the most common noises that originate from the engine bay: 

1. Humming Noise  When Accelerating

If your car produces a feeble humming noise when driving and the sound gets louder during hard acceleration, the problem is in the transmission. 

This issue is commonly found in older cars with manual transmissions, but it can also be present in vehicles with automatic transmissions.

The most probable cause of this noise is insufficient transmission fluid. 

Even though this sound is not indicative of something dangerous, if you don’t get it fixed soon, you can harm your entire transmission. Then it will take a lot of money to repair the damages.

What you can do on your own is to check the transmission fluid level and top it up if it is under the minimum level mark.

2. Loud Screeching Noise  While Driving or Car is Idle

This is one of the most common causes of car noises. 

If the car makes a high-pitched and loud screeching noise, a probable cause is a serpentine belt. This belt is meant to drive the alternator, air conditioner, and power steering pump.

If the serpentine belt gets loose or worn out, or if one of the pulleys on the belt gets jammed for some reason, the belt and pulley system can end up making such noises.

You can also use an easy hack to double-check and make sure that the fault lies in the belt.

Apply a little grease or engine oil to the belt when the engine is off. If the noise goes away, the serpentine belt was the culprit. 

You’ll need to visit a mechanic to get the belt tightened or replaced in such a case. 

3. Knocking Sound When Accelerating

The most dangerous of the car noises that originate from the engine bay is this one. 

If you notice a periodic knocking sound from the engine when it is under load, like climbing a hill or accelerating hard, the sound is being caused by a phenomenon called knocking.

Knocking, which happens due to improper fuel combustion in the car, can be extremely dangerous for the engine. 

The main causes behind this phenomenon are substandard fuel, worn-out spark plugs, and problems with engine timing. 

If such a noise occurs repeatedly, take the car to a certified mechanic to get it fixed.

4. Engine Sound is Not Normal

You can face this issue if you have recently had your catalytic converter cleaned or serviced.

Cleaning the catalytic converter does not cause any weird sounds; it just makes your car sound different than it previously did.

It’s not something you should be worried about. But if you still want to get rid of this new sound, you will have to replace the catalytic converter, and that can be outrageously expensive.

5. Engine Sounding is Louder than Usual

If you cannot pinpoint any culprit for the noise and the engine is just louder than normal, whether the car is idling or driving, the most probable cause is a bad exhaust system. 

In fact, this is what makes a car loud most of the time.

The exhaust system is what gives your car’s engine its characteristic symphony, and even a minute problem in it can result in an extremely loud engine. 

To fix this issue, you’ll need to visit a mechanic since it often involves cutting and welding the exhaust pipes.

B. Noises from the Wheels

If you have a car making noise when driving and you feel that the noise is coming from the wheels, it can be due to one of the following reasons: 

1. Squeaking Noise While Driving Without Brakes being Applied

If you hear a loud high-pitched noise from the wheels that disappears when you hit the brake pedal, the source of this sound can be the brake pad wear indicator. 

In case you aren’t aware of it, a brake pad wear indicator is added to the brake pads to warn you when the brake material wears out.

It is not unsafe to drive a car with this problem, but the warning must be taken seriously.

This noise indicates that a very thin layer of brake material is left on your brake pads and that you need to have them replaced as soon as possible.

2. Grinding Noise When Brakes are Applied

If you hear a grinding noise while driving as soon as you put your foot on the brake, it indicates that the brake pads are totally worn out and the metallic base plate of the pads is touching the brake rotor. 

This does not only make unbearable noises but also renders the brakes of the car ineffective. 

In case you have this problem, you should take the vehicle to a certified mechanic as soon as you can. 

3. Humming Noise In Car Getting Louder With Speed

The most common cause of humming noise when driving is bad wheel bearing. 

A bearing is meant to keep the friction in the wheel at a minimum. As they age with time, bearings can slip or tilt from their location or can develop internal defects that produce the sound. 

The sound is not the real issue here. If the bearing gives in, the wheel gets jammed. In such a case, getting the bearing replaced becomes the only solution to this problem.

4. Clicking Noise When Turning

If your car drives noiselessly in a straight line but gives a clicking noise when turning and the noise originates near the wheels, the cause of this is a worn-out CV joint. 

These joints allow the wheel to be turned by engine and rotated by the steering wheel at the same time. 

The solution to this problem is usually a replacement CV joint, which is a costly repair and takes a couple of hours to complete.

Clicking noise while driving in a straight line might also be caused by some other problems, which need a mechanic to diagnose and fix.

5. Squishing Noises When Going Over Bumps 

Another type of noise that cars make is the squishing sound when driving over bumps. The cause of this sound is a malfunctioning shock absorber. 

Shock absorbers are, essentially, pumps with oil in them. With the passage of time, the piston gives in and the oil squishes when subjected to a shock. 

The solution to this is either re-surfacing the piston of the shock absorber or getting a new shock absorber.

6. Loud Thudding Sound from the Wheels 

Sometimes you might hear a thudding noise from the tires of your car, especially if you are on a rough road. 

This is caused by improper air pressure in the tires. Too low or too high tire pressure can lead to weird sounds. 

You can avoid these problems by using a tire pressure monitoring system.

C. Other Causes of Noises in a Car 

In addition to the causes given above, car noises can also be caused by: 

  • Worn-out wiper blades
  • Earth leakage into the sound system
  • Loose nuts and bolts in the bodywork
  • Failed power steering pump

Frequently Asked Questions

What causes a humming noise while driving?

There can be a variety of causes. The most common ones are worn-out transmission, worn-out wheel bearings, and sometimes a bad power steering pump.

What caused a whistling noise while driving?

The most common source of a whistling sound is the forced induction methods used in a turbo or supercharger regime. Other causes include a loose serpentine belt or a jammed pulley on the belt.

Can brakes make noise while driving?

Brakes can make noise when driving even if there is no problem with them. This can be a result of a rusted brake rotor resulting from a night of heavy rain.

What is the most common cause of car noises?

The most common cause of noises coming from a car can be a loose or worn-out serpentine belt.

Are car noises bad for my car?

Yes, they are! As we said earlier, car noises indicate a problem in one of the many systems of the car. That’s why ignoring these noises can lead to severe consequences.

DISCLAIMER: All the repair, most importantly that involving brakes, must be performed by a certified professional. Working on the car on your own can make it dangerous to drive if you are not experienced in repairing cars. You might also end up doing more harm than good. That’s why you should always consult a certified mechanic to fix your car noises, along with their underlying causes.

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