Is Your Lawn Mower Spitting Out Oil and White Smoke?

Rest Easy: Resolving Your Lawn Mower’s Oil and White Smoke Issues Made Simple. Rely on our expertise to guide you through the troubleshooting process quickly and confidently.

Is Your Lawn Mower Spitting Out Oil and White Smoke:

White smoke and oil leaks from a lawnmower engine often indicate issues like a blown head gasket allowing oil and coolant into the combustion chamber or clogged breather tubes. Inspecting components and replacing damaged parts can resolve these problems.

Is your trusty lawn mower acting up? Beyond the frustration of oil spitting and white smoke lies a story of maintenance and care. Delve into the complexities behind these common problems and learn how to restore your mower’s peak performance. Your lawn deserves the best – find out how to give it just that!

Engine working, lubrication, and cooling

Before we start with the causes of the smoke and oil leakage, it helps to understand how lawnmower engines work. This makes the diagnosis easier.

How does the engine work:

The engine on a gas lawnmower combusts the fuel and air mixture to convert energy from the gas into the flywheel’s rotary motion that drives the blade. This process can be broken down into four parts.

1. Intake of air and fuel: Air and fuel are mixed precisely. If this ratio is disturbed, the quality of performance is heavily affected. Intake occurs through a valve controlled by pushrods and a cam mechanism. The carburetor and related filters govern the air-to-fuel ratio and rate of the mix.
2. Compression of the fuel-air mix: The piston moves up inside the cylinder, compressing the air-fuel mixture. The reduction enables the power when fuel is burned.
3. Gas combustion: When the piston is about to reach the topmost position, the energy starts to burn. It happens either by a spark or due to enough rise in pressure. This blast pushes the piston down, transferring power into the flywheel.
4. Removal of the remnants: When the exhaust valve opens, the remnants are pushed out to the muffler by the already-caused movement’s inertial effect.

Troubleshoot Engine: Lubrication

The oil is used for engine lubrication. Oil is added and pumped utilizing the orifices integrated into the engine. O-rings around the piston ensure oil does not penetrate the cylinder. The existence of O-rings causes the oil film to be sealed. Likewise, the gasket also acts as a seal.

Along with the Oil ring, another ring is also present, wrapping itself around the piston. This ring also plays a vital role. If the engine’s piston rings are weak, engine performance will fall drastically. Due to reduced engine activity, the lawnmower’s cutting ability decreases.

The other ring, as mentioned, is the compression ring. This ring aims to control the burning pressure inside the chamber and bring it to practical work. When you buy a replacement, ensure that you replace both Oil and compression rings. They are often sold together. 

Cooling

Lawnmower engines can be air-cooled or use a coolant. Air-cooled has a fin for an enhanced surface area that enables a fast heat transfer. Around the same time, the coolant is injected into the jackets around the engine block.

Involved components

Knowing all the active components will allow you to understand the cause and correct any smoke from the lawnmower. Smoke is induced by a problem with the functionality of one of them. And they can be rectified by managing them.

• Carburetor
• Head Gasket
• Air filter
• Oil filter
• Breather Tube
• Fuel filter
• Oil rings

Depending on color, there are three types of smoke: Black, white, and blue. There are various reasons for them to occur. Black smoke is usually due to fuel quality or quantity-related issues.

Blue and white are often correlated and caused by lubrication oil or coolant problems. Here, only white smoke, together with an oil spill, will be discussed.

Causes for white smoke from the lawnmower and oil leaks

Several causes can result in both white smoke and oil leaks. White smoke is mainly caused by oil burns inside the cylinder. This is why the reasons are the same for both problems in most cases. The list of causes will help you diagnose and fix the problem.

● Lawnmower Blown head gasket:

Suppose the head gasket of the engine is lousy, or it is partly or entirely blown. Oil and coolant seep into the combustion chamber, causing white smoke. Some oil will get blown out as well. Marking will be visible inside the hood or cover. A timely repair is necessary to avoid any future damage to the engine.

Diagnosis:

• Check for scuffs or markings or blows around the head
• Disassemble the engine head
• Look for carbon deposits of valves and piston
• If diagnosed as blown, replace the gasket. If not, reassemble all the components

Fix:

• Open the engine compartment and examine all components
• Clean the surfaces
• Clean the carbon deposits
• Check the condition of the gasket
• If completely blown, replace it
• If partially damaged, use gasket-sealant paste around. But replacing it is always the better option.
• Some products can temporarily fix head gasket issues without opening the engine. If you have limited time, this can be a temporary fix.

● Excessive oil usage:

Overfilling the lubricant oil in the lawnmower can produce white smoke. The chance of spilling some excess oil is also great.

Diagnosis:

If your engine is blowing smoke, check the dipstick’s oil level; if it is too high, remove some until it reaches the correct level.

Fix:

• The dipstick is located on the reservoir. Clean the dipstick with a cloth and remove the cap from the reservoir.
• Dip the stick for a moment and take it out again
• Check the level corresponding to marks
• If the oil level is too high, remove some by draining it through the plug below the oil pump. Or use an oil hand pump to remove some from the reservoir.

● Lawnmower Engine Oil rings:

Oil rings refrainOile oil between the piston and cylinder to seep into the combustion chamber. If the oil rings wear out, the oil will enter the chamber and burn with fuel. This problem will cause smoke. If not treated, the issue will get bigger and result in other problems.

Diagnosis:

Oil rings are an internal engine component. The diagnosis is not easy without opening the engine and checking them. These rings have a specified age from the manufacturer and should be changed accordingly.

Fix:

• It is customary to check the oil ring’s health during an engine check-up.
• Replacing the piston rings is the only option.
• Do not try a Self-repair if your expertise level is lower. Ask a professional for help.
• Ensure you use a proper replacement with the same size and shape. Check the instruction manual for details.

● The Lawnmower was Tilted or used at an angle: 

If the lawnmower is operated at very steep slopes, it can cause oil seepage into the engine block and cause smoke. The problem can also occur after you have done some maintenance on your lawnmower and tilted it.

Fix:

• When you use the lawnmower at standard angles, it should solve itself. In general, try using less steep paths.

● Breather tube

A breather tube is commonly regarded as a carburetor member but is often ignored. If there is a blockage in the hose, it will cause the lawnmower to burn.

Fix:

Clean the breather tube with some carburetor cleaner.

● Lawnmower Crankcase leaks:

Crankcase leaks can also cause white or blue smoke. Check the crankcase for leaks if your engine blows white or blue smoke.

General warning

The mentioned causes all will blow white smoke accompanied by oil leaks. Oil leaks and smoke are hazardous to the environment.

SpiOild oil will cause permanent filthy marks on the garage floor or wherever the lawnmower is parked. Proper care and maintenance will make the chance of this kind of problem smaller.

Related Questions

1. Is it ok for the 2-stroke engine to smoke?

No, it’s not ok for any engine to blow smoke. While a two-stroke engine boils oil, it should not result in any smoke. If the lawnmower is not correctly maintained, bluish-white smoke can be generated. In that case, further diagnosis is needed.

2. Can the wrong grade of lube oil cause smoke?

Yes, in some instances, especially in 2-stroke engines. Always use the oil grade that the company recommends.

3. What causes a brand-new mower to blow smoke?

Brand-new engines can have some leftover residual oil from the production process within the cylinder. After a few uses, the smoke should stop. If the smoke remains, you should return it to the dealer and let it check there. Or replace it with a new one.

4. Is an oil spill/ leak possible without white smoke?

Yes. Oil can spill without smoke. Some oil leakage can occur if the oil pump is damaged or broken. But in this case, there will be no smoke visible.

Final Remarks

There can be various reasons why your lawnmower blows white smoke and leaks oil. Smoke can trigger significant concern and anxiety. Some of the reasons are easy to fix, But some of them, like a blown head gasket, is not.

If you notice the smoke worsening when the lawnmower is at a 15-degree angle or more, it could indicate oil entering the combustion chamber, causing the white smoke. Tilting the engine at a 15-degree angle or more than a 15-degree angle can exacerbate this issue.

Identifying if the smoke increases when the engine is tilted to troubleshoot engine smoking is crucial. This can help determine what could be causing the problem. Consulting a professional is advisable if you’re unsure how to troubleshoot or what could be causing the issue.