Car Sounds Louder Than Normal: 3 Common Reasons

By Vlad Samarin July 31, 2023
Driving a car
If your car sounds louder than normal, it's essential to have it inspected by a qualified mechanic as soon as possible to make sure it's safe and to prevent further damage. The three most common reasons why a car may sound louder include exhaust leaks, problems with the muffler, bad wheel bearings and cupped tires.

1. Exhaust System Leaks or Damaged Muffler

Often, when the car gets older, corrosion can cause leaks in the exhaust system. If the leak is small, there might not be any abnormal or weird noises, but the vehicle may sound overall louder than before. It's even noticeable when revving the engine while the car is stationary.

The sound of an exhaust leak typically comes from under the vehicle. In some cases, you may also notice a stronger than before smell of exhaust gasses.|
The muffler is the last part of the exhaust system that keeps the exhaust noise down. In older cars, the inner parts of the muffler can disintegrate, and the muffler becomes more like a straight pipe causing the exhaust noise to become louder.

The solution is to have a qualified mechanic check the exhaust system for leaks and assess the condition of the muffler. The cost of repair will depend on diagnosis. In many cases, exhaust leaks originate from worn out gaskets. The gaskets between different pipes of the exhaust system are not too expensive to replace.

If some parts of the exhaust need to be replaced or welded, a local muffler shop may offer a better price than a dealer or general auto service facility.

2. Bad Wheel Bearing

Unlike exhaust leaks, the wheel bearing noise is only noticeable while driving, more so at higher speeds. A bad wheel bearing produces a humming or growling noise that corresponds with the rotation of the wheels and gets louder with speed. You may notice that the noise gets louder or quieter when the vehicle is changing direction, for example, when exiting a highway. If the bad wheel bearing is in the front, you may also feel some vibration in the steering wheel.

The solution is the same: have the vehicle inspected by a qualified mechanic. It's not always easy to pinpoint which wheel bearing is noisy, so the mechanic will have to do further diagnostics. Replacing one wheel bearing costs from $250 to $550 in an average car. Read more: When does a wheel bearing need to be replaced?

3. Cupped Tires

"Cupping" is an irregular wear pattern of the tires with alternating high and low spots of the tread material. Cupped tires cause a rumbling or growling noise when driving. The noise pattern is often rhythmic with the rotation of the tires. Some drivers describe it as "rhythmic thumping" when driving at a slower speed. At higher speeds, the noise is somewhat similar to the wheel bearing noise. In a typical car or a small SUV, the noise is more noticeable when cupped tires are placed in the front.

If you notice a rhythmic thumping or rumbling noise coming from your car, it is essential to have the tires and suspension components inspected by a qualified mechanic to make sure the vehicle is safe and that the wheels are properly torqued.
If the mechanic confirms that the noise is caused by cupped tires, the affected tires will need to be replaced to get rid of the noise. Read also: When Should Tires be Replaced in a Car?

To prevent tires from wearing unevenly, we recommend having the tire rotations done as often as recommended by the car manufacturer; typically every 5,000–10,000 miles. Checking and correcting the wheel alignment will also help to extend the lifespan of your tires. How often should the wheel alignment be done?
If your vehicle holds the road well and shows no signs of incorrect wheel alignment, consider having the wheel alignment checked every 2-3 years as a preventative maintenance. Read more about the wheel alignment.

Other reasons

From our experience, the three issues mentioned above are the most common. Other possible reasons why the vehicle may sound louder include (but not limited to):

- an improperly installed engine air filter,
- an air filter box that is not closed properly,
- a lack of oil in the engine, making it more noisy,
- bad differential or transmission bearings or gears,
- bad drive shaft (propeller shaft) support bearing.

To accurately diagnose the source of the noise, we recommend having your vehicle inspected by a qualified mechanic in a timely manner to avoid potential safety hazards and prevent further damage to the vehicle components.