Oil Change Schedule

Several of my friends who own trawlers and motor yachts tell me they change the oil every 100 hours, regardless of motor make. In the library I find the maintenance manual for cummins which says, every six months or 250 hours, which seems more reasonable.

Is there something I am missing about these maintenance recommendations?

Thanks
Gordon

Most engines can easily do the 200/250 hr oil changes.

I go about 135 hrs (1/3 of my annual trip) but it's more for analysis than changing the oil. I just want to catch anything early on the road and this is one cheap enough way of doing it. My lab says I could easily extend to 200/250 hrs cycle.

We go by the manufacturer's recommendation but then we err on the short side. For instance, if the change is due at 200 hours and we're at 120 hours but we're about to take a cruise that is projected for 97 hours, then we'll change it before leaving home. As a result we find ourselves changing 80% of the time or so before undertaking any long trip.

I generally go 100 hours, but I have a Volvo Turbo. Better safe than sorry...
Oil and filters are cheap in the grand scheme of things...

I take a very scientific approach, watch the oil color on the dip stick. While I do get my oil analyzed, I tend to watch carbon / soot loading in the oil.

As an example, my charter boat runs at 70 to 80% load most of the time and the oil is black on the stick by 40 hours. If I let the oil chage go till 100 hours, it's burning half to a quart a trip. Doesn't burn any in the first 50 hours. So it gets changed every 50. Oil and filters are cheap.

My Dodge pickup (410,000 miles) gets an oil change in the Cummins diesel every 5,000 miles. Oil is still clear on the stick; it doesn't burn any, but it's only running at 25% of max load 90% of the time.

To my way of thinking, there is a limit to how many gallons of fuel the engine can burn per gallon of oil in the crankcase. The charter boat ratio is 120 gallons of diesel per gallon of oil. The pickup is 70 gallons of diesel per gallon of oil. While the pickup could certainly go longer, every 5,000 miles is easy to remember for oil changes.

Ted

Our engine's manufacturer recommends oil changes every 500 hrs for our electronic turbo diesels and 200 for our mechanical genny. We usually go 200 on the engines and 100 on the genny because under loading is considered severe duty by the manufacturer. Oil analysis says keep sampling at same intervals.


Spell check via iPhone.

200-300hrs on both main and gennie. Only varies as don't want interval to come up in the middle of a trip. Samples show good oil condition even at end of interval, could go longer. 450C Cummins and 643 5kW Northern Lights. I sample about each third interval.

I change mine every 100 hours, AND get a sample analysis from Blackstone Laboratories (no affiliation). We have a Volvo Penta D4-260. In our case it costs less than 100 bucks for the oil, filters, and analysis.

In addition to perhaps getting an early indication of a problem, it will be nice to hand the prospective buyer a stack of analysis records with the rest of the maintenance records.

Jeff

Change oil once a year, during which I operate about 125 hours for about 35 days, for three to eight hours at a time, normally operating two to three times a month. Allow fifteen minutes to bring up engine temperature before running at cruise speed. ... Makes we wonder how often boat owners change their boats' engine oil when they hardly ever operate their boats.

For my new JD's the first 100 hours was using their special 'run-in' oil under something like 50-80% load most of the time. Since then I seldom operate as high as 50% load as there is little extra speed for me to do so. I intend to change at 200 hr one more time (500 hrs total) then stretch out to 250 hrs intervals. Nice round numbers, easy to track. And the book says 250 hrs.

I had not thought about oil analyses, but based on prompts above I now think I'll do them every 500 hrs. I recall that trends tell as good a story as a single oil analysis, and some baseline data might be useful in the future.

Every 250 hrs on my Perkins 4.236s. That's what the book says. They know best.

Once a year which is 150 - 250 hrs.


best regards / med venlig hilsen
wadden

Our Perkins Sabre / Cat 3056 non electronic versions say up to 400 hours dependent upon sulfur analysis of fuel. All we burn or. can find in NA is ULSD so 400 hours it is but like many we change annually or well below 300 hours.

Twice when mostly offshore we've gotten to 400 hours though. Visually, my oil is still clear at 100 hours.

For regulars on Boatdiesel the common Tony Athen's refrain is "never seen an engine worn out due to oil change frequency being too long." But, some enjoy ER tasks and oil changes are easy enough to do, especially if one enjoys trips to the recycling bins.

Many cruisers would do better to observe the time in Months the oil is in the engine ,rather than engine operating hours.

15-20% of oil is additives that have a time limit to their ability to work.

sunchaser said:

Our Perkins Sabre / Cat 3056 non electronic versions say up to 400 hours dependent upon sulfur analysis of fuel. All we burn or. can find in NA is ULSD so 400 hours it is but like many we change annually or well below 300 hours.

Twice when mostly offshore we've gotten to 400 hours though. Visually, my oil is still clear at 100 hours.

For regulars on Boatdiesel the common Tony Athen's refrain is "never seen an engine worn out due to oil change frequency being too long." But, some enjoy ER tasks and oil changes are easy enough to do, especially if one enjoys trips to the recycling bins.

Click to expand...

Do what the engine and transmission manufacturers say you should do, for your exact engine in marine use. Over thinking it or relying on urban legend or what some anonymous guy on the internet says he got away with... why?

I agree with frequent oil analysis on engines and transmissions; I did mine every engine oil change as it was easy. (Did transmissions then too, though they had a longer change period) Over time, it will tell you if you can cheat on the long side a little if it will be inconvenient to do right on schedule. Plus if you ever go to sell the boat, it is yet another sign of a conscientious boat owner to buyers and their surveyors.

FF said:

Many cruisers would do better to observe the time in Months the oil is in the engine ,rather than engine operating hours.

15-20% of oil is additives that have a time limit to their ability to work.

Click to expand...

Where does that come from? Oil does not degrade when in the bottle, why would it degrade in the crankcase?

Actually it can if there is moisture in the oil, which is a problem on some engines that don't get the oil hot enough to "dry out". But on an engine with proper oil temp control, moisture gets driven out and then the oil can sit in sump without concern, just like in the bottle.

It's good technique to run engine hard long enough to get oil temp up right before shutting it down for extended periods of sitting.

FF said:

Many cruisers would do better to observe the time in Months the oil is in the engine ,rather than engine operating hours.

15-20% of oil is additives that have a time limit to their ability to work.

Click to expand...

Small Yanmar diesel, but I change my oil and filters every spring and fall. I don't pay much attention to the engine hours. The oil would be changed much less frequently if I went just by engine hours. I was also changing the impeller at that schedule until I realized that was complete overkill when the one I removed looked as good as the one I was about to install.

The manual for my Volvo-Penta diesel says every 500 hours or annually, which ever comes first. So far I have done annual oil changes in the Fall just before winter layup.

Ski,
A lot of chemestry goes on in the crankcase that is imposible in the bottle.
Condensed moisture, fuel oil and other contaminants pollute the oil.

manyboats said:

Ski,
A lot of chemestry goes on in the crankcase that is imposible in the bottle.
Condensed moisture, fuel oil and other contaminants pollute the oil.

Click to expand...

Biggest thing is moisture. If that is not there, chemistry should stay pretty stable over time. That's what samples are for.

The engine manufacturers do the research, recommend the oil and the change interval. Make up your own schedule and use whatever oil makes you feel all warm and toasty - why not?

I'm with Tony Athens on this one.

Can anyone cite a boat diesel failure caused by oil? I don't mean a cooler failure or having it all run out?

Turbos fail but that's usually from running the bag off the engine then shutting down without a cool down. Like the water taxis that arrive at the dock on the plane then immediately tie and shut down.

All great feedback. We're in the "school" of every 200 hours which is about a 6 month interval. We also generally replace the engine zincs at that interval as well. As others have said if we are at less than that but leaving on a trip we do it anyway. We use a local Volvo mechanic rather than doing it ourselves as it also provides us with a through engine "check up" and check the Volvo EVC system. Case in point on the service a couple of weeks ago the mechanic found leaks from both engines heat exchangers. They were starting to leak sea water externally as shown by the salt deposits growing between the end cap and the housing.

Cancer doesn't kill anyone, it's the failure of the vital organs that does. If you believe that "no need to change" malarkey (which I tend to doubt is an accurate quote of Mr. Athens, and if it is he must of have been drinking that day or looking for new business), then go ahead, never change your oil, why be a sucker? Ya feelin' lucky?

Here, by the way, is Detroit Diesel's justification:

"During use, engine lubricating oil undergoes deterioration from combustion by-products and contamination by the engine. In addition, certain components in a lubricant additive package are designed to deplete with use. For these reasons, regardless of the oil formulation, regular oil drain intervals are required."

caltexflanc said:

If you believe that "no need to change" malarkey (which I tend to doubt is an accurate quote of Mr. Athens, and if it is he must of have been drinking that day or looking for new business), then go ahead, never change your oil, why be a sucker?

Click to expand...

George

I re read the posts and see nobody nor Mr Athens quoted as saying never change your oil. I whole heartedly agree going by the book and have so stated. DD 2 strokes need an additional caveat regarding importance of using correct oil. That fact appears well understood by dedicated DD users.

The manufacturer will surely not skimp on oil change or other maintemance recommendations so go with what they say.

Steve said:

The manufacturer will surely not skimp on oil change or other maintemance recommendations so go with what they say.

Click to expand...

exactly...most pros/boaters do it on interval so those that do it at half or 1/3 interval should ask themselves... "Do I really have a reason other than oil changes are cheap so just do one?"

Let me ask a simple question. How long is an engine supposed to last, how about the turbo? My point is that engine manufacturers have an expectation of engine and component life. In many cases the life is based on wear which likely increases as the lublicity of the oil decreases. Frankly, I would like to significantly exceed the manufacturer's life expectation for my engines. Is there anyone here who believes the oil they're taking out of the engine after 200 hours is as good as the new oil they're putting in? To my way of thinking, by changing the oil more frequently, I'm raising the average quality level of the oil in my engine. For the C series Cummins engine in my charter boat, it's about $100 for an oil change. That's a rounding error in the annual operating cost of that boat.

Ted

Ted...man..... I respect your philosophy...so I can see your point...


But yes...my engine oil analysis says my oil at 250 Hours is still doing it's job of "standard wear"...at a 200 hour change...I am beating that number by a significant amount.


That's the whole concept of decent oil analysis, to see if the quality of the oil is still there at whatever interval is recommended and the wear is "progressing" normally....which with new or old oil should stay within "normal wear numbers".

psneeld said:

Ted...man..... I respect your philosophy...so I can see your point...


But yes...my engine oil analysis says my oil at 250 Hours is still doing it's job of "standard wear"...at a 200 hour change...I am beating that number by a significant amount.


That's the whole concept of decent oil analysis, to see if the quality of the oil is still there at whatever interval is recommended and the wear is "progressing" normally....which with new or old oil should stay within "normal wear numbers".

Click to expand...

I'm looking for below "normal wear numbers ".

Ted