changing the diesel oil

[chuckg5]

Hi, for the last two years , we and our 42' vagabond sailboat have not gone very far. Just around the bay. Did not put many hours on the diesel engine. no engine hour meter . Question is , would you just not change the oil or because of the time, change it anyway?

[pcmm]

Originally Posted by chuckg5

Hi, for the last two years , we and our 42' vagabond sailboat have not gone very far. Just around the bay. Did not put many hours on the diesel engine. no engine hour meter . Question is , would you just not change the oil or because of the time, change it anyway?

For the cost of the Oil change materials I do not see the benefit in NOT doing it. I do an Oil change every fall before winter storage. My greatest concern with not doing the regular change is just forgetting about it. Suddenly not doing it one season turns into 4 season old oil with all the contaminants built up, etc.

I would stick to regular oil changes as a matter of good maintenance.

[gonesail]

with vehicles it is once a year no matter how many miles. seems like it would be the same for a boat engine. up to you.

[JoeRobertJr]

Peter Compton, Troubleshooting Marine Diesels, says to follow the instructions in the service manual, but if you don't have one, then change the oil and filter every 125 hours or seasonally, whichever comes first.

Nigel Calder, Boatowner's Mechanical and Electrical Manual, says basically the same thing about the change interval, and explains how neglecting the oil changes leads to a buildup of acids that will damage surfaces and carbon that will form a sludge that interferes with good oil flow. "A major mechanical breakdown is underway, and all for the sake of a gallon or so of oil, a filter, and less than an hour's work."

[Jammer]

A question where everyone seems to have an opinion.

[chuckg5]

thank for the feed back. I agree in changing the oil. not using the boat on the ocean as it was built for is bothersome and wears on this 73 year old 'past' sailor

[ranger58sb]

Originally Posted by chuckg5

Hi, for the last two years , we and our 42' vagabond sailboat have not gone very far. Just around the bay. Did not put many hours on the diesel engine. no engine hour meter . Question is , would you just not change the oil or because of the time, change it anyway?

There's a middle-ground approach, with a couple potential variations...

You can have engine and gear oil tested, and one of the tests can speak to remaining longevity. Blackstone Lab, for example, can do that, and their website describes details. Not expensive.

OTOH, with only a small amount of oil involved, it's probably just as cost-effective (perhaps even slightly more so) to change the oil/filter and declare victory.

In our case, 18-gallons of expensive synthetic lube -- and very useful particulate read-out, for engine diagnosis -- makes testing very cost-effective. For maybe a couple gallons or less of standard motor oil... probably not so much, for the simple question about lube viability. (Assumes old oil is recycled responsibly.)

The particulate read-out can still be a very useful diagnostic tool, though, very useful for monitoring engine wear and overall health.

-Chris

[capt jgw]

That engine holds what, 2 gallons of oil? So $50 in oil and maybe $10 for the filter why not just do it. Now on the tour boat I ran with it's big twin DD's that hold 10 gallons each it's a little more involved. When you figure in the engineers labor it's a couple thousand. But we still do it every Fall before layup and usually we get enough hours to do one mid season.

[sailingharry]

My first thought is that an engine hour meter is super cheap and very useful. My last boat had one that was non-functional. A replacement was less than $20 on ebay. You need to know what those numbers are!

But my second thought. I generally agree with the comments of the posters that said words along the lines of annually, or 125 hours. I wouldn't be afraid to push that 125 to 150 or 175 (it would be frustrating to change the oil in September with 125 hours, and then put only 10 more hours on before the end of the season). My Yanmar manual says 150. But where I would diverge with popular opinion would be what you mean by very little use. If you get 50 or 75 hours a season, change it every fall. But if by very little, you mean 5 to 10 hours a season, I would be really tempted to go to every other year. The problem with the philosophy of "it's not that hard" is that if there's no return on the investment, it's just not worth it. At the point of ridiculous, if you run the engine twice a year, once out of the travel lift and once to the travel lift, changing it after that would be laughable.

[Rumrace]

You should change you oil before storage to assure there are no acids eating away at things.
The diesel multigrades are really wonderful.

[phorvati]

One thing about oil changes. ..if its hard to do, it gets procrasinated. Once I made mine easy to do, I tend to keep up with it every 50-100hours, and before prolonged storage periods.

[bil56]

totally agree,
at least once a year, or 150h (for my Yanmar).
an oil change does not cost anything / the price of the engine or the boat.
hot oil drain of course.
an oil analysis may be advisable after 3 or 4000 hours, or in the event of a slight malfunction (smoke f.e.)


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