Lawn mower low oil symptoms are only a few but quite hard to miss once you know what they are. Whenever your mower stops working midway through a cutting and starts producing noises and black smoke, checking its oil level should be your top priority.

Lawn Mower Low Oil

This guide will explore some of the main symptoms that indicate a low oil level in the lawn mower fuel tank. Read on to determine what professional steps you can take in such a case.

What Are the Symptoms That Your Lawn Mower Has Low Oil?

The symptoms that your lawn mower has low oil include making knocking and spluttering sounds while running, quickly becoming overheated, thick black smoke coming out of the mower, an engine that flat-out refuses to start, and damage to internal parts.

Reasons Lawn Mower Low Oil

These are the major signs you shouldn’t miss while your mower runs.

– Spluttering Sounds and Noises

If the lawn mower starts producing weird noises like spluttering and knocking sounds, it is most definitely running low on oil. Starting and running the engine on low oil levels can ruin the engine’s health, so if you suspect that the engine is low on oil, then immediately turn it off right then and there.

Wait to turn the engine back on until you have checked the oil levels in the fuel tank and refilled it if necessary. There is a very little window of time while running the engine on low oil before it destroys itself irreversibly. We have seen many people persistently carry on despite their mowers producing a knocking sound, only to end up having to replace the entire engine.

– The Mower Keeps Getting Overheated

Overheating is a symptom of low oil levels in the lawn mower that is quite hard to miss. Even if your mower is a push type, you can easily tell that it has begun to overheat. Most riding types of lawnmowers will display on the screen when their temperatures rise above a certain set limit.

If the mower becomes heated a lot during a short period, then this means that it has been running on low fuel levels for a while now. More than overheating is needed for the engine’s longevity because of the risk of plastic and metal parts melting from excessive heat.

One major job of oil as fuel is to reduce friction between different engine parts while it runs. When the oil is low, these parts rub against one another, producing heat and damaging each other. You will also find it difficult to run a mower that keeps getting overheated repeatedly.

– Mower Starts Smoking

It’s safe to assume that smoke from the mower is never a good sign. A smoking mower is only sometimes due to low oil levels in the fuel tank, but it is definitely a possibility. If the smoke is coming, especially from the mower’s engine, there is either too little oil in the fuel tank or too much oil.

Having too little oil is a far worse situation because it will destroy the inner working parts of the machinery. To ensure that the smoking mower is low on oil, check if other concurrent symptoms, such as overheating or knocking sounds, are present.

The color of the smoke being produced also gives a good indication as to its cause. When the engine runs low on oil, the smoke from the engine is likely black. If the mower is smoking from too much oil, the smoke will be whitish or grey and will come from the exhaust engine.

– Lawn Mower Refuses To Start

If your mower is of a modern design with automatic responses, it will likely not even start when the oil is low. This is a good thing and will save the machine from unnecessary damage. The spark plug might fire up, but the mower will refuse to turn on. In such a case, your immediate first response should always be to check the dipstick and see how much oil is in the tank.

– Damage to Internal Parts

Your lawn mower will eventually break apart if you are not careful with your engine’s oil levels. Soon you will begin to encounter one problem after another while cutting grass. Some sensitive parts will need to be removed and replaced by newer ones.

Frequently frying engine components of your lawn mower and then having to replace them is a symptom that implies you need to keep its oil level up to date.

What To Do When Your Lawn Mower Is Low on Oil?

When your lawn mower is low on oil, it’s best to empty the old oil from the fuel tank and fill it with high-quality, top-notch oil. You have to find out where the fuel tank is located and make sure that the engine is turned off for this.

1. Find Out Where the Fuel Tank Is Located

Before adding oil to a lawn mower running low, you must locate the fuel tank first. Depending on the company that manufactured the mower and the type of mower that you have, the location of the fuel tank varies from place to place. The fuel tank is often located near and below the handle in push-type mowers.

If you are still determining exactly where the fuel tank is located, this is where the instructions manual that came with the mower will come in handy. Even if you seem to have displaced the manual, don’t worry. We are sure you can look up online to see the tank’s exact location and how to access it for a refill.

2. Choose the Best Oil for Your Mower

Undoubtedly, the best oil for all lawnmowers is the SAE-30 one. Not only is this particular oil good for the overall working of the engine, but it will work in all temperature conditions. Some people opt for the slightly more reasonable 5w-30 oil in lawnmowers, but these can be used only in warmer conditions as they tend to freeze over during winters.

3. Turn the Engine Off

Before doing anything with the mower’s machinery, take strict safety precautions first. You want to avoid putting your hand near the engine with the risk that it might start up accidentally. That is why you must not only turn the engine off and take the key out, but also disengage the spark plug.

Solutions Lawn Mower Low Oil

The spark plug is usually on one side of most lawnmowers and is identified as a protruded object. Using a screwdriver or a similar tool, you need to unscrew the protective covering over this plug. Spark plugs are very easy to disengage; most will come loose if just rotated counterclockwise a few times.

If the spark plug is too tight and refuses to budge, then fighting with it might damage it. Pour some oil around it to lubricate it and help it loosen up, then try rotating it again.

4. See What the Dipstick Says

An oil cap will be seen on the fuel tank that you will have to unscrew and take out to observe. Companies make it easy to distinguish by either painting it bright yellow or writing the word oil on it. Sometimes, the cap for the dipstick is marked by a symbol that looks like oil.

Twist the fuel cap in a counterclockwise direction and take it fully out. The oil might drip from the stick, so be ready with a towel or cloth underneath. Usually, a dipstick has two oil markings representing high and low levels. Some more innovative dipsticks will have holes, words, letters, symbols, etc.

As long as the oil lies between the upper and the lower line, that is an acceptable motor oil level, although it would help to keep the oil topped up as much as possible. If your mower has been giving you trouble with the symptoms mentioned above, the oil level will likely be below the lower line.

5. Get Rid of the Old Oil

When the oil levels within the fuel tank become too low, it’s best to get rid of the old oil before refilling it with a new one. In fact, why not make use of this opportunity to clean the oil tank too? Draining old oil from the fuel tank can be as simple as tilting the mower to pour it all out. However, this method can get too messy, so we suggest you get a siphon pump instead.

Keep a plastic or tin container underneath to collect the old oil from the mower. After tilting the mower on the side of the container, turn the drain plug counterclockwise to pry it open. This plug is screwed a bit tight, so you might need help from a wrench or a screwdriver to twist it loose.

Washing the empty fuel tank with water is going to be of no help at all. Instead, pour a small quantity of clean oil into the tank. Use it to clean the tank’s insides and dissolve the oil-based residues stuck to the inner wall. After that, remove this engine oil because it is no longer clean and fit.

6. Add New Oil

Now that you have a clean fuel tank, you can fill it with new and fresh oil. Always use a funnel because it helps fill oil neatly without potential spill out. Instead of pouring the oil container all at once, pour in increments. After each increment, check the dipstick to see how much of the tank has been filled.

It would help if you kept filling until the oil level reached the upper level of the dipstick. Make sure not to fill beyond this point even when you feel that space is still available in the tank.

7. Don’t Let the Oil Levels Drop Anymore

When you regularly add oil to your lawn mower’s engine as per its demands, the chances of engine damage from low oil will go down significantly. As a beginner, you will have to be extra vigilant about maintaining oil levels in the machines. The first time you take your mower out for work, an oil change will be needed after five hours.

Once you start regularly using a lawn mower, there are particular demands on how often the oil needs to be changed. Mowers with larger motors need their oil changed every 50 hours, while mowers with smaller engines need their oil changed after 25 hours.

These are general guidelines, and we recommend you also go through your lawn mower’s manual yourself to see if the manufacturers have given any additional instructions. Keep a can of fresh and premium-quality oil ready, so you can use it whenever the need arises.

why Lawn Mower Low Oil


Before ending this guide, it’s time to summarize the most important points discussed regarding low oil levels in the lawn mower.

  • The foremost symptoms of a mower engine with low oil levels are strange noises like knocking, spluttering, and gurgling of machine parts.
  • If black-colored smoke is seen being produced by the engine, then this could also mean that it needs more oil.
  • While going through an oil change in the lawn mower, go for the best-quality oil you can purchase, as this investment will increase the machine’s longevity.
  • The latest models of lawnmowers will only start if the oil levels in their fuel tanks are adequate, which means the oil levels should be within the upper and lower lines on the tank.

Running a lawn mower on low oil levels is the worst thing you can do to your machine. Keep a vigilant eye on the oil levels while cutting grass, and also be aware of all the symptoms discussed in this article to keep the machine in perfect health.

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