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What Happens If You Run A Lawn Mower Without Oil

It’s common knowledge that the moving parts of a machine need oil for lubrication to function effectively. However, you could find yourself in odd situations where oil gets depleted in your lawn mower while in use. 

Sometimes this will happen without your knowledge catching you by surprise. Read the rest of the article to know what happens if you run a lawn mower without oil.


Can A Lawn Mower Engine Run Without Oil? 

No, a lawn mower engine cannot run without oil. If you try to run it this way, you’re effectively killing it by damaging the engine parts beyond repair.

Whether your lawn mower engine is two or four-stroke, it requires oil during operation to smoothen the moving parts such as the crankshaft, the piston, and metal bearings. 

Also, with oil, there is less friction— the temperature of the internal engine components remains at normal levels preventing the engine from overheating. 


Several mechanical issues could arise if your lawn mower engine runs without oil. Typical signs include:

  • Smoke 
  • Overheating 
  • Sparks
  • Sputtering
  • Wearing Down

Other signs include loud knocking or rumbling sounds coming from the engine.

Your lawn mower engine will seize if it runs without oil longer, ultimately failing. The major culprit is the increased friction leading to overheating. 

Substantial damage occurs to the metal parts causing small pieces to chip away. The other problem you’re staring at is poor lubrication leading to the crankshaft and pistons interlocking with other metal parts. 

Additionally, you have to deal with the premature wearing of the piston rings, potentially resulting in low compression levels. 


How Long Will A Lawn Mower Engine Run Without Oil? 

As per various manufacturers, a lawn mower engine shouldn’t operate without oil. However, there could be scenarios where your engine runs short of oil during operation.

Different lawn mowers vary in their reaction to an oil shortage. 

For the record, a two-minute oil shortage during use is enough to cause permanent damage to the engine. However, this is not cast in stone since some engines may still have room for repairs. 

The parts that take the most beating with visible damage include the crankshaft, the piston, and the bearings. 

How Do You Know When A Lawn Mower Needs Oil? 


As already highlighted, oil is a vital component of your lawn mower engine to ensure its functionally operational. 

However, too much oil is equally bad for your engine and is a major cause of leaks and hydro locking.

You should check the oil in your mower when the mower is parked on a level surface, and the engine is off.

The dipstick is usually found on the side of the engine. It has two marks; the top mark indicates a full oil level while the bottom mark indicates low oil levels. 

The oil is at critically low levels below the lower mark.

Tip: Always turn the dipstick anticlockwise when removing it from the engine. 

How To Correctly Add Oil To The Lawn Mower?

Once you’ve checked the oil levels in your engine and determined that the amount is insufficient, proceed with the steps below.

Given the small nature of some dipstick tubes, you may need to use a funnel for proper filling.

Add a little oil as you recheck the oil level. Keep adding and rechecking until the upper mark is reached. 

Avoid the temptation to overfill beyond the upper mark. 

What Should You Do If You Accidentally Start Your Lawn Mower Without Oil? 


If you accidentally start your mower without oil, the first thing to do is to stop it immediately. Look at the below scenarios to assess the damage caused:

Scenario 1: The piston is still moving slowly.

There is a considerable chance your mower engine can roar back to life. 


Scenario 2: The pistons and other parts are welded together.

There is little you can do about it.

If the former situation occurs, check the user’s manual for guidance on how to fix it. If that doesn’t seem to work out, you’re better off enlisting the services of a technician. 



Running a lawn mower engine without oil substantially raises the stakes of it getting permanently damaged. Oil is essential to lubricate the moving parts and prevent the engine from overheating.

An engine low on oil will overheat, wear down, and seize. Consequently, the cost of repairs could turn out to be sky high. Beware! 

What Happens If You Run A Lawn Mower Without Oil

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