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The ultimate diesel inboard oil change checklist

The best checklist for changing your diesel inboard’s oil (until you find a better one)

Porto Baia di Siracusa, June 2019
Porto Baia di Siracusa, June 2019

Changing your diesel inboard’s oil and filter is like launching a rocket. The difference between success and sudden, expensive failure is a checklist.


Total time: about an hour

Engine running: 20-25 minutes

Oil and filter changing: 30 minutes

Before you start

Read your engine’s manual. Just read it. Please. It lists the volume, grade, brand, and all that for oil and filter.

Read your engine’s manual again. This time compare the steps for oil changing with this checklist. The manual wins.

Find a place that accepts used oil. Your marina’s service department, a local car garage, or a municipal hazardous waste center can help you. Ask about the maximum volume they handle and how they accept it. For example, your municipal waste center might only take up to 2 gallons of used oil and keep the container your deliver it in.

Make a shopping list of the things you need. Some things you can borrow, like lighting and a pump. Other things you have to buy or barter, like the oil and filter.

Do this during the day. Anchor or tie your boat up in calm water. You can do this on the hard, but you’ll need to find a way to run the engine for a total of 20 minutes.

What you need

How to do it

  1. While waiting for the oil to settle, remove panels, turn on the lighting. Spread out a clean rag to organize the oil pump, container, new oil, new filter, and wrench.

  2. Warning Attach the filter by hand. Do not use the oil filter wrench to install a filter.

  3. Pour the same volume that you pumped out or the amount specified in the manual, whichever is less.

  4. With a rag, wipe around the oil filter, the oil dipstick hole, and the oil filler cap.

  5. With a clean rag, check for leaks by wiping around the oil filter, the oil dipstick hole, and the oil filler cap. Inspect the rag for oil stains.

  6. Gather rags, lighting, tools, and materials. Replace panels.


Rags, clean Preferably in solid colors, not patterns. Use them to clean spills, wipe drips, and for checking your engine after changing the oil and filter.

Oil pump There are few styles of pump. The simplest, cheapest, most compact is the manual hand pump that you have to provide a container for. I prefer this type for the reasons I list and because my municipal hazardous waste service takes both my oil and its container. It works best with an assistant to pump while you maneuver the tube in the oil pan.

The more sophisticated, expensive, and bulky is the electric pump with integrated tank.

Container for used oil The container should be clear with measurements for volume. I prefer a used 2 litre clear plastic beverage bottle. That works well for me because my engine’s oil capacity is 2 litres. Before pumping oil into it I mark 0.5, 1, and 1.5 litre increments with a measuring cup and water.

Oil filter Read the instructions on the new oil filter packaging to make sure you install it properly.

Lighting Something steady, bright, and maneuverable. Examples: a utility light with a hook, a headlamp.

Engine temperature Put the engine under load to warm it up faster. My Yanmar 2GM20 takes about 20 minutes at idle to get to operating temperature.

Insert oil pump hose Push it in to the same depth as the dipstick. The ideal position is the lowest part of the oil pan. Avoid inserting it too far because it’ll either curve up or get stuck.

Pump oil Confirm that you’ve pumped all the oil by comparing the manual’s specifications, the oil level before pumping, and the markings on your container.

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At your service

Humbly yours,

Supreme Purser