How to Change the Oil in your Lawn Mower

Lawn Mower Oil Changes

Changing the oil frequently in your lawn mower engine is your best chance to extend the life of your lawn mower, saving you money.  Small engines such as those on push lawn mowers need effective motor oil to provide lubrication and distribute heat to protect the engine from damage.  Old motor oil breaks down over time and will no longer protect the engine properly.  Motor oil also gets dirty with wear particles from the engine and from dust and contaminants that are introduced into the motor with air intake during use, causing increased wear on the engine when running with dirty oil.

How often do you need to change the motor oil in your lawn mower?

The manual for your walk behind lawn mower will provide recommended oil change intervals.  The minimum oil change interval for a lawn mower should be at least one oil change per year.  Oil changes more than once a year may be needed depending  on amount of use.

How much does it cost to change the oil in a lawn mower?

The cost for a lawn mower oil change at a service shop ranges from about $15 to $30.  The cost of a lawn mower oil change will depend on if the shop transports your mower, or if you bring it to the shop yourself.  They may also recommend replacing the spark plug and sharpening or replacing the mower blade when you get the oil changed.

You can change your own lawn mower motor oil for a few dollars.  A quart of oil costs about $3- and you can get up to 4 lawn mower oil changes from one quart.  If you need to buy a siphon pump, this will cost about $25, but the pump should last for many oil changes.  A pan to collect used motor oil is free if you can find recycled materials around your house or garage, otherwise you can buy a small plastic bin for about $3. You can transfer used oil from your pan to other containers, such as empty oil bottles, allowing you to re-use the pan.

How do you get the old oil out of the lawn mower to change lawn mower oil?

Remove oil through the oil drain plug
If you’re lucky, your push mower will have an oil drain plug.  This makes oil changes really easy.  The picture below shows the location of the oil drain plug on a lawn mower.  You may need to clean grass and debris away from the base of your lawn mower engine to see the drain plug.  A small socket wrench is the tool you'll need to remove the oil drain plug from your lawn mower.

Lawn Mower Oil Drain Plug, Dipstick Tube, and Oil Sticker Locations
Image Source: Dr. Penny Pincher

Remove oil through the dipstick tube
Some small engines do not have an oil drain plug.  If your engine doesn’t have an oil drain plug, you will either need to tip the lawn mower on its side to drain oil out of the dipstick tube or use a siphon pump.  The dipstick cover can be unscrewed and removed to drain oil.

Remove oil with a siphon pump
You can use a suction pump or siphon pump to draw the old oil out of the engine.  This allows oil to be removed from the lawn mower engine without tipping the mower on its side.  Siphon pumps can be purchased at auto parts stores or on the internet for under $25.  Siphon pumps can be used to transfer oil, gas, and other fluids as well as air inflation.  The dipstick cover can be unscrewed and removed to allow the siphon pump tube to be put in place to remove oil.

What are the steps to change lawn mower oil?

Step 1.  Make sure you have new oil available before you drain the old oil.  Most lawn mowers take SAE 30 or 10W30.  You mower may have a sticker that indicates the type of oil.  If not, check the manual for the correct type of motor oil.  Most lawn mowers require about 8 oz of motor oil.  If your lawn mower has an oil filter, obtain a replacement oil filter.  You may need to order one from a parts dealer.

Step 2. Run the lawn mower for about 5 minutes to get the oil warm.  This will make it much easier to remove more of the old oil.

Step 3. Drain the old oil from your mower.  You’ll need a pan to catch the used motor oil.  
If your lawn mower has a drain plug, position a plastic cup under the drain plug and use a wrench to remove the plug.  A small socket wrench is the best tool to use to remove the oil drain plug.  Also remove the dipstick to allow the oil to drain quickly.

If your lawn mower does not have a oil drain plug, place a pan on the same side of the lawn mower as your dipstick tube, remove the dipstick cover (unscrew), and tip the mower on its side to drain the old oil into the pan.  You’ll need to tip the mower more than 90 degrees to get the oil out.  This will work best if you have a low profile pan so you have enough room to tip your mower.

If you are using a suction pump, insert one end of the tube into oil dipstick tube and place the other end in the pan you are using to collect the used motor oil.  Squeeze the pump bulb, or operate the piston, to pump the old oil out of your lawn mower.

Step 4. If your lawn mower has an oil filter, replace the old oil filter with a new one.  Unscrew and remove the old oil filter and discard.  Apply some oil to coat the seal around the new oil filter to prevent oil leakage.  Then tighten the new oil filter in place.

Step 5. Fill your lawn mower with new oil.  Replace your drain plug (if you have one) and tighten using a wrench or socket driver.  Tighten firmly, but not too tight or it will be hard to remove next time.  Place your lawn mower on a level surface and use your dipstick to check the level as you fill the oil reservoir through the dipstick tube.  You may need a funnel if your dipstick tube has a small opening.  Over filling or under filling your engine with oil can cause damage to your engine, so use the correct fill level.

Check your lawn mower oil level with a dipstick
Image Source: Dr. Penny Pincher

Step 6. Dispose of your used motor oil properly.  In some areas you will need to place the used motor oil in a container with a lid and take it to a recycling center for disposal.  Auto supply shops may also accept used motor oil for recycling.

Safety when changing oil in a lawn mower

• Use caution to avoid starting a grass fire.  Hot parts of your engine can cause grass to ignite when tipping your mower to drain oil.  You want the engine warm to help oil drain, but not too hot.
• Use caution with fuel.  You can drain the fuel from your tank, or wait until your fuel tank is empty to avoid spilling any gas if you need to tip your mower to drain the oil.  Gas can leak out the fuel cap when you tip your mower.
• You can disconnect the spark plug cap to avoid the mower accidently starting while you are working on it.

If you never want to change oil in your lawn mower again, check out electric lawn mowers!

Recommended reading:

How to check your gas mileage: Step-by-step instructions

Can You Save Money Driving a Car with Manual Transmission?

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