How To Service Your
Diesel Marine Engine!

Diesel marine engines are the lifeblood of our boats. Even on a sailing yacht, they are a necessaty. Whether to propulse our boat or charging our batteries.

To keep them in their best condition, we have to spend some time on them in a while. That way, we can always count on them, even in an emergency.

Hereunder, I will show you the basic maintenace acts that everyone can do.

In the end, as sailors, we have to be self-sufficient and be a bit of a mechanic too!

Let's begin with...

Engine Oil

"Every engine loves his oil like every sailor his rum'' they say...

Without it, your engine will be ruined!

So, choose a good quality engine oil that is recommended or, at least, is up to the job.

Don't go for the ones on the lower shelf of your local super market...

Which atlete would run the marathon the fastest? The one who eats junkfood all day, or the one who eats a well balanced diet? Exactly!

heavy duty engine oil

When you have a new engine, you have to change the oil after the first 50 hours, without exception. This, because the diesel marine engine has to run in and small particles can get into the oil.

After that oil change, it depends what the engine manufacturer states in the engine operation manual. Probably is is around 250 hours.

Before you actually start changing the engine oil, check that you have all the spare parts and the necessary tools.

Okay then!

Step 1: Let's get warm!

Start your engine and let it run in neutral for 15 to 20 minutes. Our aim is that the engine and oil heats up. The engine should be warm, so that you can put your hand on the engine block. If it's too hot, let it cool off until you can proceed.

Of course, as a matter of safety, feel with your hand after you switched off the engine. Around 15 minutes should be enough...

Step 2: Drain the old engine oil!

oil extractor

Draining the engine oil used to be a dirty job! You would spill oil all around the place and all over yourself.

Nowadays, it can't be easier.

I use the oil extractor. It's quick, easy and clean! And they come in different sizes.

handle of oil extractor

First, I remove the dipstick, then, I push the suction pipe in it.

pulling out the dipstick

pumping out the oil

Don't forget to unscrew the oil cap, so that air can move around and the oil flows freely.

Once the suction pipe is in the oil, pump a few times on the handle of the oil extractor...and have a rest.

The oil comes nice and easy in the oil extractor.

filling the oil extractor
pouring out oil extractor
old oil

When the extractor is almost full, you push the little knob on the top to stop the suction. Now you can pour the old oil nicely in another old container or bottle. 

Repeat the process if more oil is to be sucked.

oil drain

Some models have a special drain tap on the bottom of the oil pan.

That's easy as well.

Connect the tap with a suitable length of hose and put a container under it.

Open the tap!

Or you can do it with a small handpump. This is what I used to do, but I prefer the oil extractor.

Step 3: Changing the oil filter!

Now that your diesel marine engine is without engine oil, we can replace the oil filter. Do this every time that you change the engine oil!

First, unscrew the oil filter anti-clockwise.

removing old oil filter
kohler oil filter

There are special tools on the market, oil filter wrenches, to get the filter off, some with a chain, others with a rubber band.

I prefer the one with the rubber bands, because they don't damage the surface and so, I can use them to remove other things too.

Once removed, we clean the engine oil filter mounting face.

oiling o-ring oil filter

Then, we take the new oil filter and we put some fresh engine oil on the gasket.

Screw the filter clockwise on its mounting until it touches its mounting face.

Now take the oil filter wrench and tighten it further with 3/4 to 1 turn.

That's it, no more!

Step 4: Refill!

It's time to refill the engine with new fresh engine oil!

Before we actually start filling, check that all drains are closed...

Now, put a funnel in the oil filler port and start pouring the juice!

filling with new engine oil

Refill the engine with the same quantity that you have pumped out before.

After that, screw the oil cap back on and put the dipstick back in its place.

Do a last check if the engine is clear and everything is in its place to run.

If yes, turn on your diesel marine engine for 5 minutes.

Switch it back off and check for oil leaks.

If there aren't, wait a bit longer and then check the engine oil level.

level dipstick

It should be between the min and max lines on the dipstick.

Add oil if necessary.

And that's it concerning the engine oil circuit!

Continue your diesel marine engine service!

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