Yanmar 2GM20 Oil Change hacks

It’s a job that many of us complete twice a year so it should run like clockwork, right?

Sure – but marine diesel installations in small yachts can often turn even the most routine job into a bloody-knuckled affair. Here are a couple of hacks to make the job a bit easier.

Removing the old oil

The easiest way to remove the oil on a marine diesel engine is to suck the oil out of the dipstick access when the oil is warm. This is not necessarily the best way. Particles and contaminants are not flushed out in the same way as they would be if the sump plug were removed. However, access issues and the fear of oil leaks means that many owners choose to change the oil more often rather than make the job more complicated.

There are many brands and designs of oil extractor but make sure that you get one with a small helical hose fitted to the extraction hose so that it fits into the dipstick hole.

Get the correct oil filter wrench for the job

Over the past few years, I’ve built up a set of tools and hacks that make changing the oil on my Yanmar 2GM20 a little bit easier. Here they are…

The first “hack” that’s worth mentioning is the tool required to remove (or at least loosen) the oil filter. The position of the oil filter on the Yanmar 2GM20 is such that there is limited access on most installations.

Conventional chain-based oil filter wrenches are particularly awkward to use, but this strap type is an absolute joy!

Accessing the oil filler on a Yanmar GM series engine

Another common access area on Yanmar GM Series engine installations is the oil filler cap. It’s right on top of the block but this isn’t always the easiest area to access. After a couple of oil changes where I poured the engine oil into the engine from a cup, I have now fashioned an extension filler to make this much easier.

A short piece of tubing joined to a metal funnel…
…makes getting the new oil into the engine a breeze

The rubber bung on the end (and the other in the funnel) prevents oil leaking out and contaminants getting in when the tube is in storage. The clip hold the tube in place while I pour the oil in.