Question on yearly engine maintenance - with low operating time in the seaso

[mbartosch]

I am a bit reluctant to ask what might be a really dumb question, but I'd like some opinions on maintenance schedule on a marine diesel engine.

The Yanmar 4JH5CE engine on Entropy is now 8 years old, has 1000 engine hours and received its scheduled "big" 1000 h maintenance in May 2019. Basically "everything" was done in this big maintenance by professional Yanmar staff.

After this maintenance there was only an additional meagre 40 engine hours in the 2019 season.

Now my question: what amount of maintenance would YOU do for the 2020 season under these conditions?

In the past we always changed oil, coolant, filters and impellers every season, but I was thinking if I might skip any of those this time because the engine was only operated for such a short run time. Keep the impeller? And the coolant? But change oil and filters?

Bad idea? What do you do?

[kev_rm]

Coolant does not need to be changed every season IMHO, more like every 5, but I would do oil filters and impeller every season regardless of hours.

[kenbo]

I would just do oil and oil filter. And Yanmar is pretty clear on changing the coolant every 2 years on the JH series. There are no anodes anywhere on that engine and the coolant plays an important role in corrosion protection.

[sailorboy1]

Originally Posted by mbartosch

Now my question: what amount of maintenance would YOU do for the 2020 season under these conditions?

?

All would, and did back when i was seasonal even if engine had 100-200 hours the year before, is change the oil and oil filter.

[kev_rm]

I'm no expert (but I play one on TV), but I don't think anodes (nor anything on the salt water side) has anything to do with coolant change interval.

Originally Posted by kenbo

I would just do oil and oil filter. And Yanmar is pretty clear on changing the coolant every 2 years on the JH series. There are no anodes anywhere on that engine and the coolant plays an important role in corrosion protection.

[kenbo]

Originally Posted by kev_rm

I'm no expert (but I play one on TV), but I don't think anodes (nor anything on the salt water side) has anything to do with coolant change interval.

If you have a JH series engine and you've taken the end caps off the heat exchanger ends, you'll notice the smorgasbord of galvanically dissimilar metals (bronze, steel, alluminum alloy, cupronickel alloy). Corrosion can and does occur here. If it occurs, it's usually found in the aluminum alloy of the heat exchanger where the o-rings seal the end caps. Salt water is just on the other side of these metals and galvanic current can flow into the coolant side.

Yanmar is pretty clear on the type of coolant specified and the change out schedule. They have even put out service notices on this but I don't have them handy. There's two things about this series that I could never get my head around, the lack of anodes in the heat exchanger and no filter element in the air intake.

[kev_rm]

Sure, and do I need to change my transmission oil more frequently too because these parts are electrically connected to the sea water side as well? My word...

Originally Posted by kenbo

If you have a JH series engine and you've taken the end caps off the heat exchanger ends, you'll notice the smorgasbord of galvanically dissimilar metals (bronze, steel, alluminum alloy, cupronickel alloy). Corrosion can and does occur here. If it occurs, it's usually found in the aluminum alloy of the heat exchanger where the o-rings seal the end caps. Salt water is just on the other side of these metals and galvanic current can flow into the coolant side.

Yanmar is pretty clear on the type of coolant specified and the change out schedule. They have even put out service notices on this but I don't have them handy. There's two things about this series that I could never get my head around, the lack of anodes in the heat exchanger and no filter element in the air intake.

[kenbo]

Originally Posted by kev_rm

Sure, and do I need to change my transmission oil more frequently too because these parts are electrically connected to the sea water side as well? My word...

I guess you know better than Yanmar.

[NYSail]

I change the oil, filter and trans fluid every year..... over 100 hrs I would do it again. Radiator coolant every two. Impeller every 3 or so. Fuel filters... I inspect primary and go from there but usually every 3 years is good in my location..... depends on where you are of course and source of fuel.

Good luck

[mbartosch]

Thanks to all for the valuable input and opinions. I shall act accordingly

[a64pilot]

Originally Posted by NYSail

I change the oil, filter and trans fluid every year..... over 100 hrs I would do it again. Radiator coolant every two. Impeller every 3 or so. Fuel filters... I inspect primary and go from there but usually every 3 years is good in my location..... depends on where you are of course and source of fuel.

Good luck

I’m with this and I now believe that the reason you charge coolant so frequently is the very real possibility of it being contaminated with salt water, other wise a good long life coolant every 5 years would be fine, and there are ways to make coolant essentially last forever.
But not if even a tiny bit of salt water gets in.

I originally was going to use coolant that’s used in large OTR trucks and if it’s “recharged” regularly it lasts pretty much forever, until I found out about the salt water contamination possibility.

Oh, and change the transmission fluid every oil change, why wouldn’t you? You already have the change pump etc out, so go ahead and suck out the transmission fluid too.

[rbk]

Originally Posted by a64pilot

I’m with this and I now believe that the reason you charge coolant so frequently is the very real possibility of it being contaminated with salt water, other wise a good long life coolant every 5 years would be fine, and there are ways to make coolant essentially last forever.
But not if even a tiny bit of salt water gets in.

I originally was going to use coolant that’s used in large OTR trucks and if it’s “recharged” regularly it lasts pretty much forever, until I found out about the salt water contamination possibility.

Oh, and change the transmission fluid every oil change, why wouldn’t you? You already have the change pump etc out, so go ahead and suck out the transmission fluid too.

Me too. All filters and fluids (coolant can stay in a second year) but like A64 said you’ve got it all out so why not. Even if you only put 20 hours on all season, it’s nice to know you have fresh filters and fluids ready to go. This is also how you catch problems before they become disasters ie oil in coolant, water in oil etc

[mikecambrai]

I always change my engine oil and filters every year at the end of the season because I don't want the acids and other contaminants in the oil eating into the metal during the winter.
The impeller I would go for 2 years but always remove it for the winter and check that there are no visible splits between the vanes.
Transmission oil is not so important but just check that it looks clear and feels OK between the fingers. If you do have an anode in the saltwater side of the coolers, remove it and check for any wasting away.
Check the hoses by squeezing them, and check the belts for wear and that they are not touching the bottom of the groove in which they are running.
Every 2 years I would remove al the cooler ends and check that there is no debris within by putting a plastic rod down each tube. I would also remove all hoses and check their integrity. Good idea to change the transmission oil every 2 years.
The cost of all this is minimal if you do it yourself and the peace of mind that it will give you is worth it!

[ferrailleur]

Please bear with my twisted or no so twisted logics...
Not trying to be argumentative. I'm not and expert! Love to hear from the more knowledgeable.

Why change your engine oil for let's say only 20 hrs motoring in the season?

Do you change your car/SUV oil every 500 miles?

Twenty hours of your boat motoring time roughly equal 20 hrs of your car/SUV motoring time at 25miles per hour.... (speed roughly adjusted for highway/slow/idling time).

20 times 25 is 500.
Again? would you change your oil every 500 mi.?

Oil in a engine block (boat or car/SUV/truck/bulldozer, etc.) is self contained if no water/coolant/fuel is in it. If there is contamination in the oil my logics doesn't apply!

Re: the supposed "acid and oil contamination" eating away at the metals of your engine block and components over the winter. Never seen any info about it... Again: I'm not an expert.

Thanks for "listening".

[a64pilot]

Combustion of either gasoline or diesel, but moreso Diesel because of the sulphur does create sulphuric acid. Plus a lot of boats oil temps are too low to cook off the moisture, especially low use boats
Motor oil has chemicals in it to neutralize this acid, it’s known as TBN or total base number, but it of course isn't 100% effective.
You can’t compare a boat use to an automobile, even if you had one that you only used occasionally and it spent most of its life sitting, the use and temps are just so different, besides one is usually gasoline and the other a Diesel.

But it really boils down to how long do you want your engine to last, if you only use the motor 25 hours a year it’s likely you will soon bore of the boat and sell it as it’s not often used, so don’t waste your time and money changing oil. It’s like leased cars, won’t bother rotating tires and changing oil, it will last through the lease and who cares after that?

Changing oil often etc is only for those that use their boats often, as in continuously and desire the motor to last a very long time, and or have old motors and plan on not having to pay for a replacement any time soon.
If that’s not you, don’t bother

But it really boils down to how long do you want your engine to last