Here’s why your car sounds like a lawn mower

Having a car is an excellent investment that you can make, provided that you can maintain it properly. However, even with regular maintenance, your car might start sounding like a lawn mower at some point every time after stepping on the gas pedal.

This unusual sound shows that your vehicle requires urgent attention. In most cases, the strange sound is associated with exhaust system leaks.

Although this is still a cause, many other causes need urgent attention. Below are some top reasons why your car sounds like a lawn mower:

1. Leaking exhaust

The exhaust system plays a significant role in a car. It helps to remove burned gasses from the car and catalyzes them to be less harmful to the environment.

Over time, the exhaust will break, thus leading to leaks. These leaks result from expansion and contraction due to the hot substances that pass through the system.

These movements in the system make the exhaust pipe weak leading to visible cracks. The vapor eliminated through the exhaust also makes the pipe rusty leading to leaks.

It’s these gas leaks in the exhaust system that lead to these unusual lawn mower-like sounds. You’ll always hear the sounds during the ignition or acceleration phases.

The sound is interrupted mostly when there’s a bit of vibration. When you come across such an unusual sound, you should inspect your car exhaust system and find out whether there are traces of gas tapping your hand.

Exhaust leaks are dangerous since they signify the presence of harmful gases in the car’s cabin. These gases are toxic and harmful to human health.

2. Blown head gasket

Head gaskets separate the vehicle’s engine and cylinders. Their primary role is to ensure combustion gases stay away from the cooling system and restrict water and oil entry into the gas cylinder.

This makes engine cooling easier, thus improving its power and performance over time. When your car’s engine overheats, it can easily blow the head gasket.

This results from increased expansion, making it difficult for the gasket to fit in between the engine and gas cylinder. Overheating results from the continuous running of the engine, especially if the fluids aren’t changed frequently.

A blown head gasket will make your car produce a lawn mower-like sound. It has adverse effects on one’s health, including affecting hearing and producing dangerous gases.

If the problem isn’t solved immediately, it can lead to engine breakdown, which may be expensive to repair.

3. Engine misfire

Occurs due to incomplete fuel combustion in the vehicle’s cylinders. Engine misfire results in power loss and boosts emissions. It also makes your car produce a sound like a lawn mower.

Engine misfire can happen due to many reasons, including spark plug problems, compression problems, faulty ignition system, leaking intake manifold, and fuel system problems.

A misfiring engine is dangerous since it can result in your car coming to a standstill when driving, which can lead to an accident. This problem requires professional help from a mechanic.

The mechanic will diagnose the problem using scan tools or code readers and inspect possible parts that could lead to the problem.

4. Worn-out car tires

When your car has new tires, you’ll always have a smooth ride without hearing unusual sounds. This is because the new tires can withstand friction.

As your car tires age, they start wearing out unevenly, leading to a growling sound. Worn-out tires have reduced road grip and affect the brake system, which can easily lead to accidents.

Additionally, they also make steering challenging, especially driving on slippery roads. You can easily examine your car tires and find out if they’re still functional or not. Worn-out car tires should be replaced to prevent the dangers involved.

5. Old differential fluid

Differential fluid is responsible for lowering friction in the vehicle’s gearbox. It’s essential to change this fluid regularly (after at least 30,000 miles) and replace it with a new one for proper functionality.

Failure to change the differential fluid will make your car sound like a lawn mower. It’ll also lead to gear breaking, overheating, and lockup. When it becomes challenging to reduce gear friction, your car will heat excessively, increasing the risk of breaking.

6. Faulty wheel bearing

The primary role of wheel bearings is to reduce friction when a car is moving. Wheel bearings need regular lubrication to prevent rusting or wear and tear.

However, they tend to wear out over time, making your car sound like a lawn mower. This usually happens since the wheel becomes unsteady and starts moving from side to side.

You can identify this problem by rolling every wheel alone and listening if there’s such a sound. The sideways movements of your wheels can be dangerous since your car can easily lock its axle, thus making movements challenging.

Apart from the unusual sound, you can also identify a failed wheel bearing when the steering feels loose, has unusual vibration, and has uneven tire wear.

How much does it cost to fix the above-mentioned problems?

a. For a leaking exhaust

It takes 2-3 hours to repair a leaking exhaust. Most repair shops charge between $100-$400 for the repair. However, if you decide to replace the leaking exhaust, you’ll spend up to $1,200.

b. Blown head gasket

The average cost of repairing a blown head gasket is between $1,000-$1,200. Since the repair is costly, most people prefer scrapping the car instead of repairing it.

The highest cost is associated with the labor required since it’s extremely time-consuming. However, if you identify the problem earlier, you’ll not spend that much money.

c. Engine misfire

Your car needs to be diagnosed if there’s a cylinder malfunctioning. Repairing or replacing it will cost between $100-$1,000 based on the cause of the misfire.

d. Worn-out tires

The average cost of replacing 4 car tires ranges between $500-$1,500 depending on the quality, car model, tire type, and the seller.

e. Old differential fluid

It’s not that costly to change the differential fluid in a car. The fluid costs between $30-$80. The labor will cost between $40-$70, depending on the car model.

f. Faulty wheel bearing

The cost of fixing faulty wheel bearing varies depending on the car model, cost of parts, and labor rate. The average cost is around $350.


In conclusion, these are the costs to fix problems that make your car sound like a lawn mower. Whenever you hear an unusual sound in your car, you must contact a professional mechanic to diagnose and fix the problem.

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