On this beautiful Saturday morning, the sun is shining directly on the lawn, and you’re prepared to get a lot of yard work done. Your machine should be making a steady, rhythmic purr when you pull the cord or turn the key, but instead it’s squeaking, clunking, or wheezing. Isn’t it annoying? Avoid mechanical headaches and aim for a clean cut.
Take a deep breath before you go completely insane and begin searching for an alternative. In most cases, your lawnmower is actually attempting to strike up a conversation. When it makes those strange noises, it’s only trying to communicate that something is loose, thirsty, or exhausted.
Why Is My Lawnmower Making a Loud Squealing Noise?
When you start cutting with your mower, and the noise immediately becomes unbearable, it’s probably because of friction. Something is rubbing in an inappropriate place, and it’s not simply annoying.
1. The Drive Belt is Slipping
The drive belt is the most common component that might cause a high-pitched screech. Wear and tear, stretching, or glazing (a shiny, slippery coating) can occur with these belts over time. The belt tries to latch onto the pulleys when you engage the deck, but if they’re not tight, it will slip and make a loud noise.
Fix: Make sure the tension is right. A belt is useless if it shows signs of cracking or has “polished” edges. Replace it with a new one. It’s an inexpensive solution that yields significant results.
2. A Bad Mandrel or Idler Pulley
To ensure the belt runs properly, your mower contains multiple pulleys. If the pulleys’ internal bearings begin to wear out, they will no longer spin freely. The result will be a piercing, metallic screech instead, when they grind or seize up.
In order to fix it, turn the pulleys by hand while the engine is turned off and the spark plug wire is unplugged (always put safety first!). Find the one that doesn’t spin readily or feels “crunchy”; it’s your winner. Either the individual pulley or the mandrel assembly needs to be replaced.
What Does a Metallic Banging or Heavy Thumping Sound Mean?
Your pulse rate will decrease in response to this kind of sound. You must instantly turn off the engine if you hear a loud metallic bang or a strong thud-thud-thud. We are not dealing with a “finish the yard first” scenario here.
1. A Loose or Bent Blade
Your blade could be bent or loose after a recent collision with an unsuspecting garden gnome, a strong tree root, or a hidden boulder. Unsteady is a twisted blade. When spun at thousands of RPMs, the imbalance causes it to vibrate so much that it sounds like a hammer hitting the deck.
The Solution: Inspect the blade by tipping the mower over (with the carburettor facing up!). Make sure to change it if it resembles a pretzel. Tighten the mounting bolt according to the manufacturer’s standards if it’s simply loose. The experts at Consumer Reports say that the most important thing you can do to extend the life of your mower is to maintain sharp and balanced blades.
2. Debris Stuck in the Deck
It may not always be a mechanical issue. It is possible for the blade and housing to become jammed by a thick branch or a piece of dried, hardened muck. The rhythmic hammering is created every time the blade clips that location.
The Solution: Remove all cards. The old, crusty grass can be removed using a plastic scraper. Your mower will bag and mulch considerably more effectively, and the noise will also cease.
Why Is My Lawnmower Making a Clicking Sound but Won’t Start?
When you turn the key, nothing happens. “Monday morning” mower problems are the most common. In most cases, the problem is with the electricity, and fixing it is easier than you think.
1. The Battery is Drained
“Big shoutout” to everyone who neglected to secure their mower to a tender during winter. The solenoid will click quickly as it attempts to engage the starter motor if there is insufficient juice in the battery to do so.
Obtain a multimeter. That’s the fix. It is necessary to charge the battery if its voltage reading drops below 12.4 volts. Get a new one if it can’t retain a charge.
2. Loose or Corroded Connections
Those battery terminals need to be checked. Corrosion, which might appear as white or green crust, prevents the flow of electricity. Even a slightly slack cable can cause the unpleasant clicking sound.
The Solution: Use a wire brush and a mixture of baking soda and water to clean the terminals. Pull everything in closer. Believe it or not, a “dead” mower is usually only a stray wire. Check out Briggs & Stratton’s excellent engine diagnostics resource for additional information on electrical troubleshooting.
Identifying a Rattle or Constant Vibration
Rattle is the lawnmower equivalent of a nervous twitch. Something is attempting to escape, but it doesn’t indicate the engine is dying.
1. Loose Mounting Bolts
The engine is fastened to the frame using a couple of stronger bolts. These can become dislodged due to the motor’s continual vibrations and the uneven ground in your yard. The engine as a whole will sway back and forth against the frame if this happens.
Repair: Run the mower through a “shake test.” Be sure to tighten the mounting nuts if the engine moves separately from the frame. In the process, double-check the deck hangers and the bolts that hold the handles.
2. Worn-Out Engine Gaskets or Muffler
A corroded muffler or a damaged mounting bracket can be to blame for an exhaust-related rattling. Not only does a rattling muffler sound bad, but it can also alter the engine’s backpressure, leading to poor performance.
What Causes a Lawnmower to Pop or Backfire?
An audible example of a backfire might be a gunshot in the backyard. When you’re shut down or under a severe strain, it generally happens, and it’s shocking.
1. Moving the Throttle Too Fast
Transferring the accelerator abruptly from “Fast” to “Slow” can cause the unburned fuel to be drawn into the hot exhaust pipe. Pop! Your backfire has occurred.
The Solution: Ease up! Allow the engine to idle for approximately 30 seconds after you finish mowing before turning it off. This eliminates any surplus fuel and allows the temperatures to stabilise.
2. Carburetor Issues (Running Lean)
Mowing the lawn while your mower pops is likely an indication that it is “running lean.” This indicates an imbalance in the gas-to-air ratio. In most cases, this is due to an air leak in the intake or a filthy carburettor.
The Solution: Sweep the carb. To clear the tiny jets of dirt, use a carburettor cleaner spray specifically designed for that purpose. In most cases, a nearby store may do a “carb soak” for a nominal charge if you feel uneasy about doing it yourself.
The Roar: Why Is My Mower So Much Louder Than Usual?
You have an exhaust leak if your lawnmower makes a noise similar to a Harley-Davidson with a straight pipe.
- Review: Take a look at the exhaust system. Your problem has been located if there are holes, severe rust, or if it is physically hanging off the side of the engine.
- The Risk: A really noisy mower poses a fire hazard in addition to being an annoyance to your neighbours. Damage to plastic covers or even dry grass could result from hot exhaust gases escaping via those gaps. Immediately replace a muffler that has been damaged.
Breakdown of Mower Noises
| Noise Type | Likely Meaning | Severity | Recommended Action |
| High Squeal | Slipping belt or dry pulley | Medium | Check/Replace belt and pulleys |
| Heavy Banging | Bent blade or debris | CRITICAL | Stop immediately; check blade/deck |
| Rapid Clicking | Low battery or bad starter | Low | Charge battery; clean terminals |
| Rattling | Loose bolts or hardware | Low | Tighten all external fasteners |
| Backfiring | Fuel mix issue or fast shutdown | Medium | Clean carb; let idle before stop |
| Grinding | Failed bearings | High | Replace mandrels or engine bearings |
How to Prevent These Noises Before They Start?
The most effective approach to handling typical lawnmower noises and their meanings is to eliminate their occurrence. The effects of spring’s “tender loving care” are far-reaching.
The yearly check-up
Oil changes, spark plug replacements, and air filter swaps should all be performed annually in the spring. The “running lean” backfire that we discussed can be avoided with a clean air filter. Keeping the internal bearings lubricated prevents them from grinding.
Maintain a Clean Deck
This is absolutely crucial. After each cut, spray the deck’s underside. Grass becomes as hard as concrete when enough of it accumulates. This results in vibrations, increased strain on the belts (which in turn generates squealing), and a greater workload for the engine.
Invest in New Fuel
You wouldn’t believe how quickly gasoline spoils. The breakdown of gasoline after 30 days produces a “varnish” that can clog your carburettor. If you don’t plan on using the entire tank in a month, a fuel stabiliser can be helpful. As a result, the majority of popping and stalling problems are avoided.
When Should You Give Up and Call a Professional?
DIY is great and all, but there are times when you can’t handle it. A damaged crankshaft or “thrown rod” is typically to blame when an audible, low-pitched metallic grating is heard emanating from within the engine block.
Piston rings are probably shot if you notice blue smoke emerging from the tailpipe and a steady thump-thump-thump. The mower may no longer be worth the money needed to fix it. If the machine’s “skeleton” is breaking down, you should probably check out some of the best new models available.
The Bottom Line
Learning the meaning of typical lawnmower noises is similar to picking up a new language. In addition to being annoying, your mower is trying to tell you something.
- Making a terrible noise? Pulleys and belts, take a look.
- Is it resonating? Look at that blade right away.
- Engaging in clicking? It’s a problem with electrical juice.
- Is it popping? The ratio of gasoline to air is just wrong.
Your yard will continue to appear like a professional golf course without breaking the bank if you spot these noises early. Pay attention to the warnings. Get the job done, tighten the nuts, and make sure the equipment runs smoothly. Grass (and your bank account) will be grateful.
Common Questions About Mower Noises
What causes the “whirring” sound that my lawnmower makes when I switch it off?
When the engine needs to be stopped fast, this is typically the result of the blade brake pad rubbing against the flywheel. No big deal if it’s just a gentle whirr. If you hear a grinding noise, it could mean that the brake pad is worn down to the rivets.
Why is my zero-turn mower making a whining noise?
It is common for zero-turn mowers to have hydrostatic transmissions that make a whining noise. When hydraulic fluid levels are low or air becomes trapped in the system, this can occur. Be sure to “purge” the air and check the fluid levels as directed in the instructions.
Are loud noises possible when the air filter is dirty?
Yes, indirectly. The engine will “hunt” for RPMs, or surge, if the filter is clogged. This causes the engine to rev more frequently and loudly than it would at a constant idle, which is harder on the engine.
