Why are Lawn Mowers Making so Loud Clanking Sounds: 3 tips

why are lawnmowers making so loud clanking sounds

Suddenly your riding lawn mower makes a rattling noise or loud clanking sound? You also love to mow the grass or level the lawn.

But the problem is that you may have a question: why are the lawn mowers so loud when starting. Now you want to reduce that mower noise.

You are also confused about whether it is possible to reduce that noise or not?

For finding the answer, you have already searched on the internet but you didn’t get any reliable idea for reducing that mower sound.

The answer is: yes, reducing the sound of this machine is possible. For that, you should know the reliable steps that are also important for reducing common noises.

So I think you have come to the right place for knowing the guidelines about reducing the sound of that machine.

If you seriously want to decrease the noise of your existing mower, you should continue reading…

First, you should know why loud mowers make a sound?

Why Do Lawnmowers Make Noise (So Loud)?

The main focus of this machine is its working function. That is why this machine is not designed for low sound generation.

Though all the mowers are not the same, some mowers make low noise. But of course, all the grass cutters produce noise during running time.

There are some main reasons for creating that type of sound. You know that it is one kind of machine. This machine includes an engine, a rotating blade, and many adjusting parts.

The engine is the main source for generating maximum noise for this machine.

Now, you can ask me: Why are these small engines so loud?

During rotation of the blade, it creates sound waves that continue during running time.

Besides, when you power the mower (from the cordless battery or not), vibration may be created in it. This vibration is created from the joints of different parts (equipment) of the mower.

N.B: Electric mower creates less noise than usual lawn tractors.

What Sound Level Does a Lawnmower Makes a Loud Clicking Sound

Normally, a power lawn mower can make a noise that is 80 dB to 89 dB. Above 85 dB is harmful and may hurt your ear. (source)

The sound level depends on the type of parts and the quality of the mower. According to the type of engine, mufflers create high or low noise.

Is It Possible to Reduce Mower Noise?

This is the main question you can ask me.

Answer: Yes, it is possible to reduce the noise level of a mower. For doing that you need to follow some important steps. But Before that, you need to know the basic function of this machine.

I will also share the basic and reliable solutions to reduce that noise. If you have little experience with the function and working activities of this machine, you need to know the next part of what I will tell below.

How Does a Basic Lawn Mower Work?

lawn mower parts diagram

Electric and oil mowers are common in the market. Now, I will share the basic lawn mower parts with a diagram in a short description.

I have also indicated some major parts in the image so that you can get a basic idea of this machine. When you run or switch on this machine, the engine of that machine starts.

After starting the engine, the movement of the piston starts. For the piston movement, the rotating blade begins to rotate. This blade cut the grass during rotation.

The grass is stored in the grass bag which is adjusted behind this machine.

N.B: If you want to collect a quieter lawn mower, you may try (given below).

  1. Electric Mower
    If you like a low sound mower, then I would suggest you collect an electric lawnmower. Though it creates some sound, it is better than the gas/fuel engine lawn mowers.
  2. Collect ear protection
    It will be better if you collect reliable ear muffs or headphones/earplugs for hearing protection and soundproofing.
  3. Quiet Reel lawn mower
    If you don’t like the loud engine noise of a riding mower, you have a better option. You can use a push mower that will not produce an engine and muffle the sound.

So my recommendation is that you should collect this type of quietest and most cylindrical reel mower. Just you need to give the push to operate this machine. The force depends on the size of the grass.

How to Reduce Lawn Mower Noise Pollution?

A lawnmower may knock under a specific load or other problem issues. Now, I will discuss different sources of this machine noise and I will also suggest some notes that may help you to reduce noise.

1. Lawn Mower Muffler/Silencer

Engine exhaust or muffler may be the main issue for creating noise. So you need to focus on how to fix loud oil/diesel exhaust noise and the replacement of lawn mower mufflers for reducing clicking noise.

First, you should know the two types of lawn mower muffles.

lawn mower muffler

Types of Muffler

a. Reflective mufflers/Reactive silencers
A reflective or resonator muffler has a resonating chamber where the flowing sound is reduced (see the image). This chamber has an acoustic element for absorbing sound.

So this type of muffler can filter maximum noise because it has an engineering or acoustic design. Larger engine mufflers have a larger noise-reducing capability.

You have noticed that luxury cars have bigger muffles for reducing sound. But there needs to be more engine power if you use this type of reflective muffler.

The chamber of this muffler creates the restriction of gas flow. This is the reason why back engine pressure is created and engine power is reduced.

You have noticed that the racing cars don’t use this type of bigger muffler. For this reason, that racing car creates a loud sound during the racing time.

b. Absorptive Mufflers/Absorptive Silencers
It is a normal muffler that has no advanced engineering design. This is why it creates low gas flow restrictions.

Noise reduction is low and engine power is not reduced like a reflected muffler and most manufacturers normally use this type of muffler. When this silencer leaks gas, then it may create more noise.

Inspect the Current Muffler:

  • When the muffler has no heat, unscrew it for checking
  • Now, you should check if the muffler (around all sides) is cracked/damaged or not. The loose parts of that rusted muffler may create vibration. You also need to check the corrosion of the metal part of that machine. You can take the help of your local repair (muffler) shop.
  • If there is any hole existing in the muffler, you can repair this by using fiber fix tape or exhaust repair wrap.
exhaust repair wrap

This fiber fix tape can absorb high-temperature heat. So you don’t need any tension about it.

  • If you have an absorptive muffler, you should replace it with a reflective muffler if possible. Though it is costly, you can reduce noise. You can replace it with your local machine service center.

2. Gasket

lawn mower gasket

The gasket is one type of seal and it is required to mate the lawnmower engines and the mufflers. If there is any problem with this seal, a sound may be created. So you should also focus on whether this lawn mower gasket is ok or not.

3. Focus On the Mower Deck

There is normal paint under the side of the mower deck. During cutting grass, it hit this deck and finally created a high amount of noise.

You can spray sound deadening bed liner to that painted part of the deck. You can also use underbody coating on the underside of that deck for increasing more layers. After increasing the deck layer, you can reduce grass hitting noise.

Remember: You should clean the deck before implementing coating or spray.

4. Add Acoustic Material

If you can increase the layer of the mower deck, there will be low vibration in that deck. Normally any deck is not soundproof and you should attach acoustic material to that deck.

Now you may ask me what acoustic element you should use? So I want to tell you that you may apply mass-loaded vinyl to the deck section.

It will be better if you use a sound deadening mat on the deck side. Because it has self-adhesive material for adjusting to any surface.

During cutting the grass, grass hits directly to the deck surface. For this reason, the sound is created. If you add an acoustic mat to this deck surface, this hitting sound will be little.

Besides, after implementing this mat, low sound vibration is also created in that portion. This may reduce the rotating blade noise too.

Before applying this mat, you should cut it into low size panels. After that, you can attach these pieces to the deck surface easily.

5. Valve Lash of Engine

You need to check the valve lash of the mower engine and adjust it every year if possible. A good condition of valve lash reduces engine noise and increases the engine power too. You should also focus on the spark plugs of that engine.

6. Check Engine Fan

You need to clean the dust that may be stored in the engine fan. The engine of this machine may create a rattling sound (noise). You should use an effective lubricant on the gear of the engine fan.

7. Change Old Engine Oil

At the start of the new season, you should use new or fresh engine oil. Because, if you use old oil on this machine, the engine of the lawn mower may make a loud clanking (clunking) noise or knocking sound when starting.

During using new oil, the piston of the quieter engine moves smoothly without sound. You should also oil levels by providing continuous flow.

N.B: Jet engines are louder than this type of engine.

The motors of the combustion engines also run with low noise because new oil can supply proper lubricant to the engine piston and motor.

Engine oil may also reduce that noise and you should apply engine oil regularly. You may try Lucas oil if you prefer.

8. Check the Pulley and Belt Wear

mower deck belt

The mower pulley is used to drive power to the rotating belt. If that belt is worn, it may create noise. If you see that that belt has a problem, you should replace that deck belt.

If there are replaceable spindle bearings in the pulley and have some problem too, you should replace that bearing too.

9. Check the Lawn Mower Blade

There is also a bearing in the rotating blade. In the blade spindle that bearing is adjusted. The spinning blade can freely rotate for this bearing.

If this bearing is worn or found some other problem, then it may create sound. Sometimes, the riding mower makes the sound (noise) when the blades are engaged with each other.

So check this bearing by rotating the blade. If you can hear the noise that is coming from the bearing of the rotating blade, then you should replace it with a mower repair shop.

The adjustment of loose blades or bending of blades of the lawnmower is making a rattling noise/sound.

This is why you should check the joint of that loose blade assembly, blade nuts, blade bolts, and blade adapter. If you find loose assembly, tighten it as necessary.

10. Body Linkages

You should check the body panels and deck linkages of this machine. During the running time of the engine, the joint of body panels may vibrate and create a squeak or rattle sound.

At this time you can apply Grease (lubricant) to the joint and vibration area of the total body panels of that machine. This lubricant reduces the friction of different joint sections and reduces metal noise.

11. Wheel Bearings

You should also check the bearings of the front and rear wheels. If you notice that some noise comes from these shaft bearings, you can apply lubricant. Before applying any lubricant, you should clear the dust. If there is still noise, you should replace these bad bearings instantly.

12. Tighten the Screws

Find the loose screws and tighten them with the wrench. During vibration of the motor, these loose screws also vibrate and make a rattling sound (noise).

You may need to open the cover for finding any loose screws. But you should do that and properly tighten them.

Thinking of using the new design lawn mower?

My Overview

Finally, I want to say that, you should know the basic idea about this machine if you don’t know anything about it.

This is why I have tried to share the overall noisy issue of that machine. After reading the total blog, I think you may get reliable notes for reducing noise from this machine.

For your easy understanding, here, I have also easily shared the working function so that like you everyone can understand the basic principle of a general mower.

In this post, I have also described the noise-reducing procedure of that machine. You should read that for quick learning.

The muffler of this machine is also a reason for the noise. If the existing muffler has a problem, you can also repair it easily.

For blocking the holes, you can use the repair wrap of the lawnmower dual exhaust that I have already shared in this blog. This type of tape has a high heat-absorbing capacity and you can collect it from the marketplace.

Besides, you can also use a reel mower that doesn’t have an engine. That is why it doesn’t create engine-related sound. But you need to operate it by manual pushing.

This pushing system is not hard work. Many people are also using this type of machine. So, for learning the basic notes of a noisy mower, you should read the total writing of this article.

For new learners, I have tried to represent the mechanical language simply. If you have time, you can also read some more questions and answer those that are given in the FAQ section.

FAQ: Why Does a Lawn Mower Make a Metallic Sound

Why are All the Noisy Lawn Mowers So Annoying?

All machines are not annoying and reel mowers have less sound than power-generated mowers. I think people who don’t like sound can prefer this type of reel machine.

Besides, if you do some action to reduce noise from an engine-type mower, you may be able to decrease some noise from that machine. I have already shared some reliable notes that you can follow.

Why is an Electric Lawn Mower Making a Loud Noise?

The main noise source of the electric mower is the deck area where the grass is cut by lawnmower blades.

The electric motor of that machine is less noisy than that deck. You can add an acoustic element to this deck side for creating low vibration. You also know that low vibration means low noise.

Is It Worth Replacing the Lawn Mower Engine?

If you replace the engine, the cost of the engine will be high. So the better decision is that you should collect a new one.

But if you think that the engine of the older mower is not working properly, you can repair it from a local mechanical shop. If you can repair that old engine, you don’t need to collect a new one.

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