I replaced the oil and filter 12 months ago with 15W40 Diesel Oil. I only put 25 hrs on the engine since last change! Does it make sense to change it again this year or is it an overkill?? Thanks.
Yanmar Engine Oil Change
- Thread starter Lee Hadjiosif
- Start date
You do not state which Yanmar model you have but the 3YM30 Service Manual states "150 hrs or one year" whichever comes first. Also the engine lube oil filter will need changing as it is scheduled for 250 hrs or one year, again whichever comes first.
If your boat gets hauled each season, I believe it is best to drain the oil and replace with fresh at the haulout, regardless of when the oil was last changed. I replace the oil filter at each oil change. Having clean oil in an engine is the best way to prevent wear and tear.
I take a bit of a contrary view here.
If you change the oil and let the boat sit, you have achieved nothing.
Running the engine (at least) every month will move the oil where it is supposed to be.
It will also it will move the coolant and rotate the impeller.
New oil and filter in an engine that sits is oil that just sits and that is pretty useless.
So, to sum up. forget the oil change and run the engine.
gary
If you change the oil and let the boat sit, you have achieved nothing.
Running the engine (at least) every month will move the oil where it is supposed to be.
It will also it will move the coolant and rotate the impeller.
New oil and filter in an engine that sits is oil that just sits and that is pretty useless.
So, to sum up. forget the oil change and run the engine.
gary
I'll see your contrary and up you two:
1. you want to replace the oil just before winter layup or at any time the engine is not to be used for a long period . Reason: corrosion inhibitors, acid neutralizers, are just a few of the inhibitors which degrade with operating hours. You want your engine parts bathed in new oil with full strength chemical protection during that lay up.
2. Don't run your engine at the dock because it never gets a chance to heat up the oil to a temperature where the water from the combustion products accumulates. If you really want to re-oil the engine internals, roll it over with the starter and the engine stop pulled until the oil alarm stops.
Both of the above statements are based on the theory of oil chemistry and diesel operation. Clearances in an engine are pretty small and don't drain with ease.
Now, having said all that, I think the jury is still out as to whether there is a marked decrease in engine performance depending on oil changing habits.
Last edited:
Well, the important factor in oil is viscosity while the great enemy of viscosity is heat and diesel engines tend to run hot. This is why whenever the engine suffers an overheat condition the oil should be changed. Oils have improved a lot in the past few years and some of the Owner Manuals recommendations may be outdated depending on the year model of the boat. The reason they may recommend changing the oil at least once a year probably has more to do with removing contaminants, like condensation or combustion byproducts than with the actual integrity of the oil. This is what I do, I will rub a little oil between my thumb and forefinger to feel for the thickness of the film in the oil and as long as I feel the film as it feels in the new oil I will continue to use it irrespective of time. I will yield to the hours and if I run the engine more than 100 hours in a year I will replace it.
Overkill…..never! It’s the best and nicest thing you can do for your engine. (Any engine you own)
Cheapest insurance you can buy for a stressless sailing season. And it puts you in areas of the engine you would normally not look at during the year. That heads off other issues as well.
Change it
Cheapest insurance you can buy for a stressless sailing season. And it puts you in areas of the engine you would normally not look at during the year. That heads off other issues as well.
Change it
I’ve heard it said that regular oil changes extend the working life of an engine by reducing the rate of frictional wear through its use. That assumes as Bennie noted that the oil remains in good condition. Oil can lose functional quality over time just sitting in the crankcase, as well as by many hours of lubricating a running engine. I doubt that the oil can ever be in too good of a condition, so there could be no “overkill” as far as the engine would be concerned. However, there could be “overkill” as far as labor and/or cost are concerned.
Most diesels far outlast recreational owner use on the average of maybe 100-150 hr/yr for local cruising. The Yanmar 3JH3E in our Bavaria after 23 yr of use is probably barely at 50% of its life with 2500 hr of operation. I don’t see another 2500 hr (another 23 yr?) for us unless we get going somewhere. So, an “overkill” on oil maintenance probably would not affect the longevity of use of most owners. That is, the engine will usually survive an owner’s interest in it with only “usual” maintenance. Change every 150 hr or once a year, which ever arrives first; oil filter change every other oil change, etc.
Most diesels far outlast recreational owner use on the average of maybe 100-150 hr/yr for local cruising. The Yanmar 3JH3E in our Bavaria after 23 yr of use is probably barely at 50% of its life with 2500 hr of operation. I don’t see another 2500 hr (another 23 yr?) for us unless we get going somewhere. So, an “overkill” on oil maintenance probably would not affect the longevity of use of most owners. That is, the engine will usually survive an owner’s interest in it with only “usual” maintenance. Change every 150 hr or once a year, which ever arrives first; oil filter change every other oil change, etc.
Last edited:
The only reason to change it prior to laying up for the season is condensation which will happen with old or new oil so why not wait till commissioning for the season? The idea of changing out the oil so the it's "contaminants" don't hurt the engine while in storage not logical. The engine isn't being bathed in the oil sitting in the pan.
Makes sense to me. In Northern latitudes, you guys haul out in October and don't splash again until April or May. So the engine is sitting unused with new oil in the pan accumulating condensation; when you start using it again in the Spring, now you have condensation in the oil when you are going to start using it again. Seems to me that changing oil in the Spring would be better. Just conjecture on my part. Guess I would go with the majority opinion. It would be interesting to determine if any manufacturers or repair facilities have a grounded opinion on the proper protocol.
I'm going to disagree with the statements of oil filter change frequency. The oil filter is usually the weakest link in your engine lubrication system. There do exist long term oil filtration systems on diesel engines- think stationary diesels running in remote places (oil pipe lines are an example) where the diesel engine runs 24/7 - 365. If you do the numbers these engines are running almost 9000 hours a year and in some locations are only able to be serviced once every 6 months or so. The oil filters on these engines are highly specialized and are aimed at long term usage.
The filters on our engines are not made that way and should be changed with each oil change. In fact, if running fully synthetic oils, you could likely change the oil filter only at the prescribed oil change interval and not change the oil. I personally wouldn't do that unless I were doing the oil analysis . There are folk that look at this a lot and there appears to be data supporting that fully synthetic oil lasts double to triple the oil change interval and that the change interval is actually based on the filter breaking down more than the oil. I'd post references but I'm in the middle of a bunch of heavy "stuff" and dont' feel like looking it up...
dj
The filters on our engines are not made that way and should be changed with each oil change. In fact, if running fully synthetic oils, you could likely change the oil filter only at the prescribed oil change interval and not change the oil. I personally wouldn't do that unless I were doing the oil analysis . There are folk that look at this a lot and there appears to be data supporting that fully synthetic oil lasts double to triple the oil change interval and that the change interval is actually based on the filter breaking down more than the oil. I'd post references but I'm in the middle of a bunch of heavy "stuff" and dont' feel like looking it up...
dj
If you wait until spring to change your oil, you still have to run the engine first, to warm it up. Now you are dispersing the old contaminants with any condensation throughout the engine. I have never noticed any sign of condensation in the engine come spring. The oil is always clear, and there is no indication of moisture. Anyway, I have 17 years of experience with my Universal diesel and the gas engine of my RV, storing them for the winter, and have had excellent results so far.
I certainly understand your perspective. I change my oil annually, usually in Spring. Run the engine at dock once a month during off season. No evidenced based research; just what I have always done.
True. But I feel better knowing my baby has fresh oil in her for the winter.