How to Check Oil in a Lawn Mower

Dirt and debris can wreck havoc on your mower. Learn how to check the level and quality of your oil, and when it's time for an oil change.

Whether you’re gearing up for summer or winterizing your lawn mower before retiring it for the season, it’s imperative to know how to check your oil and make sure it hasn’t expired.

When to Check Mower Oil

The frequency of lawn mower oil changes depends on the type of mower and how much you use it. It’s always a good idea to check all mower levels — gas included — before each use. Automotive expert Rick Muscoplat provided Family Handyman this oil change breakdown for reference:

  • For new mower engines, change and replace the oil soon after its first use, roughly five hours of run time.
  • For existing push mowers, like in the video below, change and replace the oil at least once a season or for every 50 hours of run time.
  • For existing riding mowers, change and replace the oil at least once a season, or for every 100 hours of run time.

Always check you’re using the right type of lawn mower oil. The wrong type of oil can ruin the mower.

How to Check Oil in Lawn Mower

Engine oil tank capannick vanderschelden photography/Getty Images

The location of the lawn mower oil tank cap will vary by equipment. Typically, you’ll find it on top of the mower with an oil can symbol on the cap. The cap may resemble the gas cap, so double-check which you’re opening.

Underneath and connected to the oil cap you’ll find the dipstick, a long, thin metal rod. Remove it, wipe off the oil with a paper towel or disposable rag and reinsert the dipstick. Make sure it’s all the way in at the correct angle.

Remove the dipstick again, look for two notches and see if the oil level falls between them. If so, that indicates there’s enough oil and you’re good to do. If it’s below the first notch, add additional oil into the hole where you removed the dipstick. Your owner’s manual will tell you the size of the oil tank and the type of oil it takes.

Pour slowly and check occasionally as you refill the tank.

How to Know Mower Oil is Bad

Motor oil degrades over time and will eventually go bad, even if it’s just sitting in the engine. Before adding new oil, check the oil can for an expiration date. If it’s expired, dispose of it the right way.

You can also use your dipstick to check the quality of the oil already in your mower. The oil should be amber and clear. If it’s hazy, burnt or contains debris, it’s time for an oil change.

Alex Shoemaker
Alex Shoemaker is a Florida-based journalist and  handyman who has extensive experience in home remodeling and house flipping. He has worked for numerous print and digital publications and has won awards for writing, photography and pagination.