Why Is My Lawnmower Making Loud Noise? How To Fix A Noisy Lawnmower?

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We all know lawnmowers are loud machines. But over time, their sound may increase if any internal issue arises. If you use your lawnmower regularly, you can easily differentiate between typical sound and deafening noise.

Why is my lawnmower making loud noise?

Your lawnmower can make loud noise due to clogging up issues, loose drive belts, old oil, lack of oil for shaft bearings, loose blades, or defective muffler. 

A lawnmower makes a loud noise for different causes, such as

  • Loose drive belt
  • Clogging up issues for blades or cutting deck
  • Too old oil
  • Lack of oil for shaft bearings
  • Loose or curved blades
  • Defective muffler

You want to take immediate action the moment you notice any unnatural sound from your lawnmower. Delaying will add more damage to the machine. Also, the sound will increase gradually. In this post, we will share the root causes of excessive sound for your lawnmower and how to fix them.

Why Is My Lawnmower Making Loud Noise?

When do you want to know why is my lawnmower making loud noise? There could be several causes behind it. Let’s learn them one by one.

1. Loose Drive Belt

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The most common reason behind the loud noise of your lawnmower could be a loose drive belt. However, the good news is that you can solve this problem independently without facing any hassle.

Belts that allow blades to spin have come loose from the engine driving the mower deck. As a result, a problem arises between the guides and the belt.

2. Clogging Up Issue For Blades

Why Is My Lawnmower Making Loud Noise - Clogging Up Issue For Blades

Have you checked if your mower blades don’t stick with anything like line or rope? This is another typical cause, which we often overlook.

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If this happens, the blades can’t rotate smoothly to cut grass. As a result, a loud noise will come from the blades. Running the machine faster will increase the sound more.

3. Lack of Oil For Shaft Bearings

Why Is My Lawnmower Making Loud Noise - Lack of Oil For Shaft Bearings

A shaft bearing is an important component for lawnmowers, which helps to take the load. Lack of oil for this component may make the mower prone to make excessive sounds.

4. Curved Or Twisted Blades

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Have you noticed if your lawnmower blades are curved or twisted? While the curved blades spin, they enter inside the casing, causing some damage and unwanted loud noise.

Check out how the blades spin while you run the mower. Also, inspect carefully in which parts the blades contact.

5. Too Old Oil

Since when did you last change the oil in your engine? Do you regularly replace the engine oil for optimal engine efficiency?

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Using too old oil may harm the different components of the lawnmower. It is because the oil quality doesn’t remain the same when they sit for a long time inside the tank.

So, what is the relation between old oil and loud noise? Right?

The low-quality engine oil fails to lubricate the engine components efficiently, unlike fresh oil. When natural piston flow is absent, the machine doesn’t run smoothly, causing a loud noise.

6. Clogging Up Issue For Cutting Deck

Why Is My Lawnmower Running Slow - Clog-up Issue

Like blades, clogging up issues can occur for cutting the deck, especially if you don’t clean it regularly. Cutting thick and long grasses for hours will store dust, tiny grasses, and grease underside the cutting deck.

Even if your lawnmower doesn’t make any unnatural sound, you should always clean it. The metal surface will collect water from the grass clippings and develop rust over time. If you are careless cleaning the cutting deck, you may change it soon.

7. Defective Muffler

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The main job of a muffler is to control the mower exhaust’s sound, and it helps to achieve an incredible reduction in noise.

However, if the muffler is defective or gets displaced from its location, noise reduction may not be possible. Hence, more loud noises will come from your mower while operating.

So, how will you know your muffler is defective? Right? A faulty muffler will have some cracks or holes in its body. Also, you will fail to install it perfectly after removing it.

How To Fix A Noisy Lawnmower?

Fixing a noisy lawnmower has several things to do. First of all, you want to figure out the type of problem your lawnmower is having. And you want to implement the solution based on it.

Different problems need to be addressed differently. If you are unaware of the right method to fix it, you will end up damaging the components.

Wondering how to fix a noisy lawnmower? Here are mentioning the solution based on problems (the causes we have said).

1. Solution For Loose Drive Belt

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If your lawnmower is facing this common issue, you should address it as early as possible. A loose or slipped drive belt can be fixed just by taking it back in its original position.

In addition, you want to line up the belt perfectly between the guides. Otherwise, the component will be damaged, and you will have to change it after a particular time.

2. Solution For Clogging Up Issue For Blades

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In order to address the issue, you want to clear everything from blades areas. Take a hard bristle brush to eliminate grime, tiny grass, and grease from the blade body. Cleaning them will eliminate the unnatural sound.

3. Solution For Lack Of Oil For Shaft Bearings

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If the mower makes noise due to the lack of oil for shaft bearings, adding oil will reduce the loud noise.

In order to include oil in the shaft bearing, you want first to take off the cover and then add oil. It is uncomplicated and straightforward!

4. Solution For Curved Or Twisted Blades

How To Fix A Noisy Lawnmower - Lawnmower reshaping blade

Fixing this issue is hassle-free —all you need to detach the blades, reshape them using a hammer into their original shape, and reinstall them in their previous place.

While detaching the blades from the mower, watch out carefully how they have been placed. Because you want to put them at the perfect location without 1 mm of difference.

In addition, we recommend that you don’t strike the hammer too hard. You may damage the sharp surface of the blade by hitting it too hard or in the wrong spot.

5. Solution For Too Old Oil

First of all, pour out the old oil through a tube and add new oil as per your engine compliance. It is best to change mower oil before starting each season so that you can enjoy the mowing session.

6. Solution For Clogging Up Issue For Cutting Deck

How To Fix A Noisy Lawnmower - lawnmower deck cleaning

Use a hose and a piece of scraping equipment to clean out everything beneath the cutting deck. If it becomes excessively dirty, use sandpaper to remove dirt from the surface.

Be careful while sliding the mower on one side. You may end up leaking the engine, which involves spending extra money.

7. Solution For Defective Muffler

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The best solution for a defective muffler is to buy a new one. They are low in price, costly only $20-$40. Plus, using a damaged muffler will increase the sound more.

While changing the muffler, let the engine cool down at least for a few hours. Installing a new muffler is a straightforward task. You just need to find out the mower exhaust outlet and place the muffler’s threaded end in it.

So, these are the solution to the question of how to fix a noisy lawnmower? Make sure to follow them correctly without making any mistakes. If you are not expert enough, we recommend you take professional help.

How Do I Know If My Lawnmower Has A Blown Head Gasket?

It is an easy task to troubleshoot a lawnmower, especially if you are a regular gardener. We often face various issues on our lawnmower, and a blown head gasket is one of them.

But, the question is, how do I know if my lawnmower has a blown head gasket? There are a few tell-tale signs that can help you make an immediate diagnosis. Here are they:

1. Leakage Issue

leakage issue in the gasket

The first common thing you should notice is any leakage issue in the gasket. The location of a head gasket will vary based on its model and brand.

If there is any leakage issue in the gasket, you will notice an oil line where the two pieces are joined. Due to the leaking problem, the oil will come from the fuel tank

2. Low Power

If your lawnmower has low power, you will struggle to start the machine. Or it will stop automatically in the middle of the mowing session.

Because of it, your lawn mower may have a blown head gasket. Sometimes you will notice oil leaking and low power issues together.

Even if your lawnmower doesn’t have an oil leakage issue, but the machine stops the middle, it might have a blown head gasket.

3. Smoke Coming From the Exhaust

The Most Common Lawnmower Problems and Reasons (White smoke)

Have you noticed if the exhaust producing any smoke? If yes, the combustion system might have some issues.

But the question how is it related to a blown head gasket? Right? It is because a bad or blown head gasket is probably the primary reason behind the smoke as in place of the fuel, oil is filling the chamber.

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When do you want to know how do I know if my lawnmower has a blown head gasket? You should check out these symptoms.

How Can I Make My Lawnmower Quieter?

Besides knowing why is my lawnmower making a loud noise? It is also important to learn this question: how can I make my lawnmower quieter?

Silence and lawnmower are like one is an enemy to the other. So, it means you can’t operate a lawnmower in a fully quiet manner. But the least you can do is reducing its sound.

How can I make my lawnmower quieter?

You can make your lawnmower quieter in several ways like setting up an engine silencer, using a perfect muffler, or buying the quietest lawnmower.

Step 1 – Setting Up A Engine Silencer

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If you own a combustion-type lawnmower, installing an engine silencer will help you in reducing the sound. The silencer decreases the excessive noise during combustion.

An engine silencer comes in two types:

  • Absorptive silencer
  • Tuned Dissipative Silencer

Absorptive Silencer

If you want to reduce or dampen very high frequency or volume sound, absorptive silencers can help you. It has a common design, which is made from porous and fibrous wadding components. Sound waves are moderately modified into heat energy as they pass through insulative substances.

Tuned Dissipative Silencer

A Tuned Dissipative Silencer is a perfect option to reduce low and mid-level noise. The silencer is mainly connected to the engine exhaust — by restoring the sound waves to their original source, the device reflects them back to it.

Step 2 – Inspection Of Deck

How To Fix A Noisy Lawnmower - lawnmower deck cleaning

Often, a lot of noise comes from the deck. You can make the deck quieter by using sound damping materials. Plus, make sure the bearings of the deck are perfectly fine.

If any wear and tear issue appears on the deck bearings, it will produce vibration, which will ultimately cause more sound.

Step 3 – Pay Attention To The Muffler

A full of debris or dirt muffler may cause a cracking issue, which will lead to excessive noise. If the muffler is heavily damaged or cracked, you want to replace it.

While buying a muffler, try to choose a small size —because noise is generally higher with longer mufflers than those with shorter lengths.

Step 4 – Wear Protective Earplugs

Wear Protective Earplugs while running lawn mower

Did you fail to reduce the mower sound even after trying each solution? If yes, the best thing you can do is wearing protective earplugs. Moreover, you can’t dampen the sounds entirely even if they worked.

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Using this lawnmower for a prolonged time will do damage to your ear dumps. Many people have already experienced hearing problems because of using noisy machinery.

Your ears will be safe as it blocks the excessive sound reach in your ears. You can use these earmuffs or earplugs to noise significantly while operating the machine.

Alternative Step – Buying Quieter Mower

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It is true that all lawnmowers make sounds. But you will find some, which produce less sound than others.

Mowers powered by electricity make less noise than those powered by gas. In addition, large-sized lawnmowers make more sound than small-sized lawnmowers.

So, if you think installing a silencer is expensive, we recommend you purchase a new one, especially if your mower has already become old.

How Do I Make My Briggs And Stratton Engine Quieter?

Are you using a Briggs And Stratton lawnmower? Do you think your lawnmower has more sound compared to other mowers?

How do I make my Briggs And Stratton engine quieter?

One of the best ways to make your Briggs And Stratton engine quieter is to use a long exhaust pipe size with a protective cap. This trick is pretty useful when you are looking for a cheap and effective solution.

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However, make sure the engine is free from any internal problems. Having any internal issues may cause loud noise. If you are planning to buy a Briggs And Stratton lawnmower, try to choose the latest one.

According to the company, they have succeeded in reducing noise up to 65% in their new gasoline-powered mowers. Hopefully, you have gotten the answer to this question: how do I make my Briggs And Stratton engine quieter?

How Do I Know If My Lawnmower Muffler Is Bad?

If your lawnmower has a bad muffler, you can detect it by inspecting few things. If your muffler is damaged, it will cause blockage issues, misfiring or overheating, and loss of power.

How do I know if my lawnmower muffler is bad?

If your lawnmower muffler is bad, you can detect it by 3 warning signs:

Serial No. Warning Signs
1 Excessive noise
2 Fuel efficiency
3 Unpleasant scent

1. Excessive Noise

If your lawnmower muffler is bad, you will notice a drastic change in the sound of the muffler. Generally, mufflers are supposed to run on with natural sound without being excessively noisy.

In that case, you want to take professional help to test out the exhaust system of the lawnmower. Delaying the inspection will increase the sound more and cause other additional issues.

2. Fuel Efficiency

How often you had to fill your fuel tank nowadays? Is there any significant change you have noticed, like decreasing the fuel level too fast?

If you fill the fuel tank more often than before, one common cause could be a bad muffler. Monitor how much fuel the machine is consuming for each mowing session. If it is consuming too much oil, you want to take professional aid.

3. Unpleasant Scent

Another devastating sign is an unpleasant scent coming from the exhaust system. When your muffler works naturally, smoke will come out from the engine. However, if the muffler is bad, smoke will be stuck inside the motor. It will ultimately spread an unpleasant scent as the smoke can’t come out.

So, these are the 3 key probable causes of this question: how do I know if my lawnmower muffler is bad?

Final Thought

Are you still seeking the answer to this question: why is my lawnmower making loud noise? We don’t see any reasons for that as we have already discussed all the probable causes of this issue. Hopefully, you have finally succeeded in reducing your lawnmower sound. If not, you should take the mower to a nearby shop.

Last update on 2021-10-15 / Affiliate links / Images from Amazon Product Advertising API