Learning how to change oil of lawn mower is a routine maintenance task that protects the engine from wear and overheating. Doing it yourself saves money and ensures your mower runs smoothly for seasons to come. This guide will walk you through the entire process, from gathering tools to disposing of the old oil safely.
How To Change Oil Of Lawn Mower
This section provides the complete, step-by-step procedure. Before you start, always consult your owner’s manual for your specific model’s requirements, as steps can vary. The general process, however, remains consistent for most walk-behind and riding mowers.
Tools And Materials You Will Need
Having everything ready before you begin makes the job quicker and cleaner. You likely have many of these items already in your garage.
- Fresh engine oil (check your manual for the correct type and quantity)
- A new oil filter (if your mower has one)
- An oil drain pan or old container
- A funnel
- Socket wrench or adjustable wrench
- Gloves and safety glasses
- Clean rags or paper towels
- A piece of cardboard or a tarp to work on
Step-By-Step Oil Change Instructions
Follow these steps in order for a successful oil change. Work on a flat, level surface and ensure the engine is cool to the touch to avoid burns.
Step 1: Prepare Your Lawn Mower
First, run the engine for a few minutes to warm the oil. Warm oil flows out more easily, carrying more debris with it. Then, turn off the engine and disconnect the spark plug wire. This is a critical safety step that prevents the engine from accidentally starting.
Place your cardboard or tarp under the mower. Tilt the mower carefully, usually with the air filter and carburetor side up, to avoid fuel leaks. If your mower has a drain plug, you may not need to tilt it.
Step 2: Drain The Old Engine Oil
Locate the drain plug on the bottom of the engine deck or the oil fill tube. Position your drain pan underneath. Using your wrench, carefully loosen and remove the drain plug. Allow all the old, dirty oil to flow completely into the pan.
If your mower does not have a drain plug, you will need to tip the mower and carefully pour the oil out through the fill tube. Using a funnel in the pan can help catch the stream. Let it drain for several minutes to get every last drop.
Step 3: Replace The Oil Filter (If Applicable)
Many riding mowers and some larger walk-behind models have an oil filter. If yours does, now is the time to change it. Use an oil filter wrench to unscrew the old filter. Before installing the new one, dab a bit of clean oil on the rubber gasket of the new filter. This ensures a good seal. Hand-tighten the new filter according to the instructions on its label, usually about a three-quarter turn after the gasket makes contact.
Step 4: Refill With Fresh Oil
Once the old oil is fully drained, replace and tighten the drain plug securely. Wipe any spilled oil from the engine area. Using your funnel, pour the recommended type and amount of fresh oil into the fill tube. Check your manual for the exact capacity; overfilling is just as bad as underfilling.
After adding most of the oil, wait a minute for it to settle, then use the dipstick to check the level. Add small amounts until the oil level reaches the “Full” mark on the dipstick. Do not overfill.
Step 5: Final Checks And Cleanup
Reconnect the spark plug wire. Wipe up any oil spills on the mower deck or engine. Start the engine and let it run for about a minute, then check for any leaks around the drain plug or filter. Turn off the engine, wait another minute, and recheck the oil level on the dipstick, adding a little more if needed.
Properly dispose of the old oil at a recycling center or an auto parts store that accepts it. Never pour it on the ground or into a drain.
Choosing The Right Oil For Your Mower
Using the correct oil is vital for engine longevity. Your owner’s manual is the final authority. Common designations include SAE 30 for warmer temperatures, 10W-30 for variable climates, and synthetic blends for enhanced performance.
- Oil Type: Look for a detergent oil classified for “small engines” or “lawn mower use.” API service classification SJ or later is typical.
- Viscosity: This is the oil’s thickness (like SAE 30). Use the weight recommended for your expected operating temperature.
- Synthetic vs. Conventional: Synthetic oils offer better protection in extreme temperatures and can extend intervals between changes, but conventional oil is perfectly acceptable if changed regularly.
When To Change Your Lawn Mower Oil
Sticking to a schedule prevents engine damage. A common rule is to change the oil every 25-50 hours of operation or at least once per mowing season. For brand-new engines, an initial change after the first 5 hours is often recommended to remove break-in metal particles.
Signs you need an oil change include the oil appearing very dark and dirty on the dipstick, the engine running louder or hotter than usual, or if it’s simply been over a year since the last change, even with light use.
Common Mistakes To Avoid
Avoiding these errors will make the job smoother and protect your engine.
- Using the Wrong Oil: Always follow the manual’s specifications.
- Overfilling or Underfilling: Check the dipstick carefully. Too much oil can cause smoking and pressure issues, while too little leads to rapid wear.
- Forgetting Safety: Always disconnect the spark plug before starting any maintenance.
- Improper Disposal: Old motor oil is a pollutant and must be recycled responsibly.
- Overtightening: Stripping the drain plug or filter housing is a costly mistake. Tighten firmly but do not force it.
Troubleshooting Oil Change Issues
If you encounter problems, here are some simple solutions.
Oil Leaks After Change
Check that the drain plug and oil filter are tightened securely. Ensure the old filter’s gasket didn’t stick to the engine, creating a double-gasket seal which always leaks. Wipe everything clean and run the engine to pinpoint the leak’s source.
Engine Won’t Start After Oil Change
First, double-check that you reconnected the spark plug wire. Ensure you did not accidentally dislodge or damage other connections while working. Verify you used the correct oil type and quantity; an overfilled engine can sometimes be hard to start.
Oil Appears Milky Or Foamy
This usually indicates water has gotten into the oil, often from condensation or storing the mower outside. You need to change the oil again immediately to prevent corrosion. Try to store your mower in a dry place.
Frequently Asked Questions
How Often Should I Change My Lawn Mower’s Oil?
You should generally change your lawn mower oil once per season or every 25-50 hours of use. Always check your owner’s manual for the manufacturer’s specific recommendation, as it can vary by model.
Can I Use Car Oil In My Lawn Mower?
You can use car oil in your lawn mower if it meets the engine manufacturer’s specifications for viscosity and API service classification. However, oils labeled specifically for small engines are often better suited for the higher operating temperatures and different engine designs.
What Is The Easiest Way To Change Lawn Mower Oil?
The easiest way is to use a mower with a dedicated drain plug and a built-in or attachable pump. For mowers without a plug, an oil extraction pump that siphons oil out through the dipstick tube can simplify the process immensely, eliminating the need to tilt the mower.
How Do You Change The Oil In A Riding Lawn Mower?
The process is similar to a walk-behind mower but often includes an oil filter change. Typically, you locate the drain plug underneath the chassis, drain the oil, replace the filter, and refill through the fill tube on the engine. The oil capacity is much larger, so have a big enough drain pan ready.
Changing your lawn mower’s oil is a straightforward task that pays off in engine life and performance. By following these steps, using the right materials, and maintaining a regular schedule, you keep your mower in top shape. Regular maintenance like this ensures your mower is ready whenever you need it, season after season.