Learning to change the oil in your lawn mower is a key step in becoming a responsible equipment owner. Knowing exactly how to change the oil in lawn mower will save you money, extend your machine’s life, and ensure it runs smoothly all season long. This guide provides clear, step-by-step instructions for this essential maintenance task.
How To Change The Oil In Lawn Mower
Changing your mower’s oil is a straightforward process. You will need a few basic tools and about 30 minutes of your time. The core steps involve draining the old oil, replacing the oil filter if your model has one, and adding fresh, clean oil. Let’s start by gathering everything you’ll need.
Tools And Materials You Will Need
Before you begin, collect these items. Having everything ready makes the job faster and cleaner.
- Fresh engine oil (check your owner’s manual for the correct type and quantity)
- A new oil filter (if applicable to your mower model)
- An oil drain pan or old container
- A funnel
- Socket wrench or adjustable wrench
- Rags or paper towels
- Gloves (optional, but recommended)
- A piece of cardboard or a tarp to work on
Preparing Your Lawn Mower For Oil Change
Proper preparation is crucial for a safe and mess-free oil change. Follow these steps to get your mower ready.
Run The Engine To Warm The Oil
Start your mower and let it run for 5-10 minutes. Warm oil flows out more easily and carries more contaminants with it. Be sure to do this in a well-ventilated area. Never attempt to change oil immediately after use, as the engine and oil will be extremely hot.
Disconnect The Spark Plug
This is the most important safety step. Locate the spark plug wire and disconnect it from the plug. This prevents the engine from accidentally starting while you are working on it. Secure the wire away from the spark plug terminal.
Position The Mower For Drainage
Place your mower on a flat, level surface. You may need to tilt it slightly to access the drain plug or to ensure all oil drains out. If you tilt it, be careful not to tilt it so far that fuel or oil leaks from other areas. Putting cardboard underneath can catch any drips.
Draining The Old Engine Oil
There are two primary methods for draining oil: using a drain plug or using a siphon pump through the fill tube. The method depends on your mower’s design.
Method One: Using The Drain Plug
Most modern mowers have a dedicated drain plug. This is often the cleanest method.
- Locate the drain plug on the underside of the mower deck, near the engine.
- Place your drain pan directly underneath the plug.
- Using your wrench, carefully loosen and remove the drain plug. Allow the oil to drain completely into the pan.
- Once drained, clean the drain plug and its threads with a rag. Reinstall and tighten the plug securely.
Method Two: Siphoning From The Fill Tube
Some older or simpler mowers lack a drain plug. In this case, you’ll need to extract the oil.
- Remove the oil fill cap/dipstick.
- Insert a manual or pump-style siphon tube down into the oil reservoir.
- Pump or siphon the old oil out into your drain pan until the reservoir is empty.
Whichever method you use, let the mower sit for several minutes to ensure every last drop of old oil has drained out.
Replacing The Oil Filter
Not all lawn mowers have a replaceable oil filter. If yours does, you should change it with every oil change for best engine protection.
- Locate the oil filter on the side of the engine. It looks like a small metal or plastic canister.
- Place your drain pan under the filter to catch drips.
- Use an oil filter wrench or your hands to turn the filter counter-clockwise to loosen and remove it.
- Before installing the new filter, dab a bit of fresh oil on your finger and wipe it around the rubber gasket on the top of the new filter. This ensures a good seal.
- Screw the new filter on by hand until the gasket makes contact, then tighten it an additional three-quarter turn. Do not overtighten.
Adding The New Engine Oil
Now it’s time to refill the engine with clean oil. Using the correct oil type is vital for engine health.
Choosing The Correct Oil Type
Always refer to your owner’s manual for the manufacturer’s specific recommendation. Common types include:
- SAE 30: A common single-weight oil for warmer temperatures.
- 10W-30: A multi-viscosity oil good for a range of temperatures.
- Synthetic or conventional blends: Check your manual for any specifications.
Using the wrong oil can lead to poor lubrication and engine damage.
Pouring And Checking The Oil Level
- Insert your funnel into the oil fill tube.
- Slowly pour in about three-quarters of the recommended amount of oil. Check your manual for the exact capacity; it’s often around 20 ounces.
- Wait a minute for the oil to settle in the crankcase, then remove the funnel and wipe the dipstick clean.
- Insert the dipstick fully, then remove it again to check the level. The oil should be between the “Full” and “Add” marks.
- Add small amounts of additional oil, checking the dipstick each time, until the level reaches the “Full” mark. Do not overfill.
- Once filled, securely replace the oil fill cap/dipstick.
Final Steps And Cleanup
You’re almost done. A few final steps will complete the job.
- Reconnect the spark plug wire to the spark plug.
- Start the mower and let it run for a minute or two. This circulates the new oil. Listen for any unusual noises.
- Turn off the engine and wait another minute. Check for any leaks around the drain plug or oil filter. Also, check the oil level one more time with the dipstick, as some oil may have circulated into the new filter.
- Properly dispose of the old oil and filter. Take them to an auto parts store, service station, or recycling center that accepts used motor oil. Never pour used oil on the ground or into the trash.
- Clean up your tools and wipe any spills from the mower deck.
Common Mistakes To Avoid
Being aware of these common errors can prevent damage to your mower.
- Overfilling the oil: This can cause excessive pressure, oil foaming, and engine smoking.
- Using the wrong oil type: Always follow the manual’s viscosity and service rating (like SJ, SL).
- Forgetting to reconnect the spark plug: The mower simply won’t start if you forget this step.
- Not disposing of oil properly: Used motor oil is a major pollutant and must be recycled.
- Overtightening the drain plug or filter: This can strip threads and cause leaks.
Frequently Asked Questions
How Often Should I Change My Lawn Mower Oil?
You should change your lawn mower oil at least once per mowing season. For heavy use, change it every 50 hours of operation. Always check your owner’s manual for the manufacturer’s specific interval, as some newer models may have longer recommended periods.
Can I Use Car Oil In My Lawn Mower?
Maybe, but it’s not always recommended. Many car oils contain additives that can harm small engines. It is best to use oil that meets the small engine specifications outlined in your mower’s manual, often marked as suitable for “lawn mower use” or “small engines.”
What Is The Best Way To Drain Oil From A Lawn Mower Without A Drain Plug?
The best way is to use a fluid extractor or siphon pump. Insert the tube down the oil fill tube and pump the old oil out into a container. You can also carefully tip the mower on its side with the fill tube facing down over a pan, but be cautious of fuel and debris spillage.
What Happens If I Put Too Much Oil In My Lawn Mower?
Too much oil can cause serious problems. The crankshaft can aerate the oil, turning it into a foamy substance that does not lubricate properly. This leads to overheating, excessive smoke from the exhaust, and potentially severe engine damage. If you overfill, you must drain the excess oil to the correct level.
Is It Necessary To Change The Oil Filter Every Time?
Yes, if your mower has a replaceable oil filter, you should change it with every oil change. The filter traps metal particles, dirt, and other contaminants. A clogged or old filter cannot protect your engine effectively, making the fresh oil less useful.