Why My Car Sounds Like A Lawnmower When Idling?

If you’re wondering what makes your car sounds like a lawnmower when idling. It may be because of an exhaust system leak although it is also possible that a failed wheel bearing could cause enough “rumbling” to sound loud.

In this article, we are going to discuss in detail the topic.

Should You Leave Your Car’s Engine Idling?

Idling is when a driver leaves the engine running and the vehicle parked. Every day in the U.S. millions of cars and trucks idle needlessly, sometimes for hours. An idling car can release as much pollution as a moving car. You may not be able to avoid keeping your engine running when you’re stopped at a traffic signal or stuck in slow-moving traffic. But other times idling is unnecessary.

Contrary to popular belief, restarting your car does not burn more fuel than leaving it idling. In fact, idling for just 10 seconds wastes more gas than restarting the engine. Warm up your engine by driving it, not by idling. Today’s electronic engines do not need to warm up, even in winter.

Reasons Behind Car Sounds Like A Lawnmower When Idling?

The exhaust system is located on the underside of your vehicle. It is responsible for processing your vehicle’s emissions by reducing the number of pollutants which is released. It also minimizes the engine exhaust noise and force. Engines produce dangerous gases as a byproduct of the combustion process. Which is considered very dangerous for human beings. This is why your vehicle must have a properly functioning exhaust system.

If a car sounds like a lawnmower when idling it is most likely due to an exhaust system leak. Exhaust noise, such as a “lawnmower” type sound should never be ignored because it may indicate an exhaust system leak which can release carbon monoxide into the cabin of your vehicle and negatively impact your health and well-being.

Following might can also be the reasons for the causing of this problem:-

1. Faulty Spark Plugs:-

If your car shakes, bounces, or makes odd noises like squealing, ticking, or like a lawnmower when it’s idling, there could well be a spark plug issue that needs your attention. Spark plugs are responsible for igniting the combined mixture of fuel and air within your vehicle’s combustion chamber. If one of yours is damaged or isn’t installed correctly, your car may be burning through fuel at a spotty, sporadic rate.

2. Leaky Vacuum Hose:-

All vehicles rely on a vacuum system to pull fuel into their engines. The great majority of them do this via an entire network of hoses and tubes. However, some newer vehicles have a throttle system that keeps the airflow through the system regular and regulates engine function.

Even the best vacuum hoses will accumulate wear and tear, eventually requiring replacement. Old hoses develop leaks, allowing too much air to mix with your fuel. One sign that this could be happening is during a rough idle, especially at a higher RPM. Another is an engine that misfires which causes loud noises.

3. Dirty Fuel Injector:-

Cars equipped with fuel injectors aren’t necessarily immune to a noisy or rough idle. Fuel injectors can accumulate dirt and grime over time, just like carburetors can. If your car sounds loud when idling, has been getting poor gas mileage, or both, a dirty carburetor may be the issue. As with carburetors, fuel injector cleaners can help you keep your system clean, efficient, and fully functional.

4. Carburetor Issues:-

If you drive an older vehicle, the chances are pretty good that it relies on a carburetor instead of a modern fuel injector. If you’ve been hearing odd car sounds under the hood or dealing with a rough idle, a carburetor issue is possible. If your system is also producing black smoke, you can be almost certain your carburetor is the culprit.

Signs Of Your Carburetor Is Failing:-

1. Engine Performance Reduction

2. Black Exhaust Smoke

3. Engine Backfires or Overheats.

What Sound Does A Lawnmower make?

Lawnmowers and sound go together like bread and butter; its the reason for which it was specially recommended for wearing the hearing protection at all times. Supposed if you’re idling your car in the traffic and the first of all, one of the most common sounds that you will hear like a lawnmower from your car is a squealing sound. The lawnmower sound makes a squealing sound and it can be unbearable at many a time.

How To Deal With The Issue Of Lawnmower Sound While Idling?

An improperly functioning exhaust system can affect both your vehicle’s performance and your ability to drive, which is why it is important to have your exhaust system maintained at regular intervals.

Step 1:-

Proper maintenance service should address all the components of the exhaust system including the exhaust manifold, front pipe, downpipe, catalytic converter, and muffler.

Step 2:-

There is a need to repair the exhaust system leak which includes sharp odors or a feeling of drowsiness while driving which may indicate a leak of noxious fumes into the cabin of the vehicle, sounds such as rattling, or a loud “lawnmower” type noise when accelerating due to holes or cracks in the exhaust system caused by rust or corrosion which can lead to an exhaust leak.

Step 3:-

Exhaust leaks are often a result of corrosion which is why it is imperative to have a trained automotive professional routinely inspect all components of your exhaust to determine the source of the leak and repair the damage.

Step 4:-

There is a need to replace the entire exhaust system in the future in order to ensure your safety.

Hence, to safeguard your vehicle from all these types of problems in the future you need to take the help of the professionals who will help to diagnose this problem of car sounds like a lawnmower when idling very well.


We hope the above-mentioned information will be helpful to all the viewers in dealing with this problem of car sounds like a lawnmower when idling. If anyone’s doubts persist feel free to comment in the comment section below we’ll definitely try to solve all the problems as soon as possible.

Leave a Comment