To Change or Not to Change? That is the Question.

Oil changes at sea get pretty close to a universal response from boaters I know. Everyone says loudly “DON’T DO IT.”  The risk of something going wrong when hundreds, if not a thousand miles, from shore is simply too high. And, with oil change intervals ranging between 250 and 375 hours, there typically is no need to change the oil at sea. Why take an even small risk of an issue when 250 hours is 1,625 nautical miles and a perfect reasonable 375 hours would take you out to 2,400 nautical miles.  The majority conclude it’s simply not worth it.

I generally agree, and in the 6+ years we have operated Dirona, we have never changed the main engine oil at sea. What’s makes the question interesting here is we are now going 3,650 nautical miles. Dirona‘s range with all fuel it can carry is not far beyond this point. It’s a long, long way. In fact so far, that we need to slow down to 6 kts and perhaps even 5.5 kts.  At 5.5 kts, that’s is 663 hours at sea — just about a month. So, even though we just changed the oil a week ago in St. Helena at the start of the trip, in 3 more weeks it will be past double the engine manufacturer’s oil change interval. When I was in high school I worked at an oil change shop and got to see the negative impact of people forgetting to change their oil. Many time I’ve drained oil that was so thick with impurities that it came out in globs. Very ugly.

I’m sure our engine would be fine not having the oil changed.  It’s a big, tough tractor engine. But we are averaging more than a thousand hours a year and operate at fairly high power levels when coastal cruising. We tend to drive it hard and, with the rate the hours are mounting, we need it to last a very high number of hours.  When we bought the boat, my goal was to make 12,000 hours without the engine cylinder head needing to come off and out past 15,000 hours without engine overhaul. At the time, that seemed like an impossibly high number of hours. It’s like talking to a 16-year-old about living past 30. It’s just doesn’t feel like an issue but, as that age looms near, it starts to feel “young” and lasting longer starts to look like a priority. Same thing with our engine. At over 7,000 engine hours, longevity is starting to feel like a very real issue and my 15,000-hour goal no longer feels like a far away target. I lean towards doing the oil change at sea, even understanding the downside risk.

Let’s look at the risk. Generally, as with most life safety issues in modern society, the risk of a fault is actually fairly low, but the downside impact of a fault can be very high. Our John Deere has started before the first turn of the engine every time I’ve pressed the start button for 7,173 hours.  It’s very reliable. But, if it doesn’t start after the oil change made 1,800 miles from the destination, then we have a pretty big problem.

We carry a lot of spares, so we can manage many of the unlikely fault scenarios without substantial impact. Amongst the most likely is a starter failure, and we do carry a spare.  Unfortunately, I recently came across a mention in the Deere manual that Deere special tool #KJD10213 is needed to change the starter. We work hard to be fully prepared for any reasonable issue but I guess I missed that one. What are the odds there will be a boat in the area willing to lend me a Deere Part #KJD10213? :-).

Another concern is simply doing anything different. One thing I’ve learned from being around big engineering projects over the years is faults are very densely packed around the unusual. For example, power failures that bring down servers in data centers are very rare with the high degrees of redundancy usually employed. But, when there is a fault, it’s amazing how many servers don’t power back up after it. When something different happens, “near” faults become real faults. There is some risk to doing anything different.

A further concern is that it’s been 2.5 years, since Dirona has had bottom paint, Prop Speed treatment, and the wing engine Gori folding prop greased in New Zealand. It’s all looking fine, but there is a chance, if we shut down the main engine and use the wing, that the wing engine prop will not deploy correctly from the folded position. This isn’t particularly likely but the reverse is very possible. The prop may not be able to refold when we return to the main engine which would add drag and slightly reduce fuel economy. And spinning the prop without the engine running is hard on the wing transmission if the ZF15 doesn’t have the oil pump on the output shaft (I’ve not checked on this).

Changing the 200°F oil in an active sea way brings some risk as well. I generally like doing the oil changes hot—actually I don’t like it but the engine does—so it’s not all that different from usual. But, the oil would be somewhat hotter and the boat will be moving around more in open ocean. Another more minor issue is the heat in the engine room. We currently are running around 110°F and it may be warmer as we near the equator. Generally, the engine room runs about 30°F over ambient temperature. 110°F is taxing but not dangerous and I have a large fan I can use for safety reasons if major work is needed in the ER while the engine is operating at sea. This one probably is more of a comfort issue than a real risk.

The last time we had this debate on Dirona we needed to cover 3,023 nautical miles with the same fuel load, so we were able to run faster. The conclusion at the time was not to change the oil which still seems like the right decision for those circumstances. But, on this run, I lean towards shutting down the main engine just before the equator and doing an oil change even though there are some low probability, but potentially high, downside risks.

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34 comments on “To Change or Not to Change? That is the Question.
  1. Steve Coleman says:

    Hello James,

    It’s amazing since I thought I’d worked my way through your entire blog but, Chad hawking amzoil popped up a section I’d never seen before. Makes me wonder what other things I’ve missed.

    In the U.S. Navy, we weren’t a bit shy about shutting down whatever piece of equipment we wanted, when ever we wanted but, we also had 80-100 (depending on the stage of crew transfer) people to work through whatever problems cropped up.

    I can completely understand why one or two people some distance from a landfall would be hesitant. You can’t even think of all the possibilities let alone be prepared for them.

    One of the trickiest situations I ever saw was actually while we were in a 4 point moor doing dive operations with the MK V suit.

    I had just gone off watch and they decided to parallel another generator and somehow screwed up and both engines shut down at the same time running both generators down to zero volts before the reverse currents had a chance to kick.

    These where self excited DC generators and the result was they no longer had magnetized fields and where unable to produce any voltage.

    No big deal really we had a third generator which while not large enough to adequately power the ship would allow us to run the motor generators that excited the fields on our propulsion generators.

    We would have had to drop our anchors and tackle but being a rescue/salvage ship recovery wouldn’t have been a problem at a later date. We wouldn’t have done that anyway but I mention it because we were still able to get underway.

    The major problem was we had divers over the side and the while main engine generators in addition to supplying power to the propulsion motors also supplied the dive compressors so while they were in no danger of running out of air, we could not run the crane used for the stage to raise and lower them.

    In theory they could have dropped weight, blown the suits up and been pulled on board with manpower by their umbilical however, rate of assent would have been tricky, and yanking them up by the umbilical was something we weren’t going to try unless it boiled down to do it or loose them.

    We did have Hyperbaric chambers and a medical doctor on board for the divers even still, time was not something we had in abundance as they’d already been at working depth for some time and living in a hyperbaric chamber isn’t something people generally enjoy doing.

    It took me probably less than hour to re-magnetize the fields on both generators and get them online, but it was close to being one of the most hectic hours of my life and seriously doubt it was a cakewalk for the divers.

    I’m not saying I wouldn’t shut down but with two people on board but, like you, I’d have thought about it long and hard.

    • Steve Coleman says:

      And when I say ME, it’s only in reference to being the one that knew what to do, if I hadn’t had an abundance of people to deal with different parts of the evolution it would have been MUCH longer.

      • With more experience, we have come around to about the same position on this one as you. We have now shut the engine down 3 times for service at sea. Because the main hydraulic pump is a live pump (non-clutched and always driven), the only way to shut down hydraulic system is to shut down the main engine. If the engine needs to be run without hydraulics for longer periods, the procedure is to shut it down, remove the hydraulic pump, and install a blanking plate over the PTO. At this point the main can be run indefinitely without hydraulics.

        For short term hydraulic service, it’s most efficient to shut down the main engine and run on the wing engine. I’ve done this for the oil change but I’ve also done it to bring down the hydraulic system to replace the port side stabilizer fin actuator hydraulic ram. There is always a chance of engine failure but the wing engine is a reliable backup and we have a lot of main engine spares including ECU, all sensors, high pressure pump, low pressure pump, and all injectors.

  2. Jamie W says:

    Alternatively: you could just pour some sand in and tell the engine it better harden up.

  3. Knut Hildebrand says:

    Hi James here is the official text for entering Fernando de Noronah from the Noontide web page:
    This is now an official port of entry and yachts are expected to arrive with all the appropriate visas. However, although all the other paperwork can be delt with, it is not possible to clear Customs here. It is reported that this does not present a problem if it is done at the next port of call.

    Once anchored go ashore to deal with clearance. Arriving yachts must clear with the port captain’s office, Park Administration (I.B.A.M.A.) and Immigration.

    Report to the office at the root of the mole. The Polica Fereral will then come to the same office to complete all paperwork making this a most convenient, if expensive, place to enter Brazil.

    It is best to be very clear about you next port of call and your expected date of departure from Brazil. You can always change your mind, but they cannot deal with uncertainties here.

    The Port official is very helpful regarding information and obtaining local cash.

    Last updated November 2011.

    • Given we don’t have the required visas and our planned destination is Barbados, our plan is to stay focused on the planned end game but thanks for putting options on the table Knut.

  4. David Magda says:

    You wrote: [blockquote] It’s all looking fine, but there is a chance, if we shut down the main engine and use the wing, that the wing engine prop will not deploy correctly from the folded position.[/blockquote]

    In hindsight, would it be a good idea to have something in your annual or biannual maintenance list about deploying and testing the wing engine? Preferably close to shore.

    Going back to your computer analogy: if you don’t test failover every so often (and don’t have active-active HA, using two main engines like on some Nordhavns), then can you really rely on it?

    David (who works in IT)

    • 100% right David. The wing on Dirona gets a lot of use and it is tested frequently. In 6 years of use, we have run up 723 hours of wing engine use. You’ll see many Nordhavns with 10 years and only 100 hours on the wing so 723 is actually pretty good. It gets used to drive the hydraulics so it’s running whenver we need thrusters or windlass. Lots of owners chose to only start the wing when they for sure need the power. We start it if there is any chance we’ll need it — it runs in any close quarters situation — on the argument that we are going to change the oil once a year no matter what. There is no value in using it less. We also run the wing after heavy seas to ensure the exahust check valve continues to work well. But all these runs are the Wing only and don’t test the transmission and prop. So, as you recommend, our maintenance spreadsheet has the “excercise wing prop and mechanical systems” every 3 months (4 times a year).

      The wing will almost certainly run and we have enough spares to get it going after most failures. The combination of it being a very low tech engine and us having lots of spares makes it a reasonably good bet it will start. And, we won’t shut the main engine down unless the wing does start so I’m not worried about it.

  5. Jacques Vuye says:

    I was thinking of Fernando de Noronha too when we had this discussion James. But this is a Wildlife preservation area 5 For Sea turtles / Chelonia essentially (-: ) and the Brazilians make you pay a hefty fee for dropping anchor , and that is only if they granted you a visitor’s permit.
    It is however a superb scuba diving area …but again for a fee and only under very close supervision from the authorities.

    • Entering Brazil is complex in general with US citizens requiring Visas (which we don’t have). I suspect that it would be possible to negotiate entry in an emergency but, generally, we would prefer to not have to do that. I was unaware of how much more complex entering Fernando de Nornha was. Thanks for the additional data Jacques.

      We’ll stay focused on Barbados and hope that weather and mechanical faults don’t force any changes.

  6. Timothy Daleo says:

    I am sure you have looked at every possible location en route but Knut above mentioned the path I was going to suggest. On your current route you pass within 120 nm of Ilha Fernando de Noronha.


    If you did the oil around 4° (Tuesday morning?) and it became serious you could head there on the wing. I am sure someone on the island has a welder to make the 15mm Deere wrench if you needed to change the starter or fix something else while at anchor. It would be a couple days out of the way if you had to go there (and then North) but a couple hundred gallons of diesel from the island would put you right back on track.

    • Timothy, I agree that would be a good location for recovery if there any problems. However, it’s actually a bit on the early side which, given how long we have been at sea so far, seems impossible but it is. We have the last of our high quality oil that allows an oil change interval of 375 hours in the engine right now. It can take us out 100 hours (roughly 4 days beyond) the proposed location. And, if we change it there, the new oil would have a 250 hour oil change interval but there would be 325 to 350 hours remaining.

      Somewhere just the other side of the equator would be slightly better from an oil change interval perspective and would still allow perfectly viable alterative routings although, I agree, none as short as the location you and Knut pointed out.

      • Timothy Daleo says:

        Ok, changing at the Equator is still only 280 miles from shore so if something goes South so can you. In the meantime are there some options/scenarios you have played with in regards to the starter? You were an auto mechanic so is a solenoid rebuild/replacement an option? Dremel a 15mm wrench? Run a Monte Carlo on it :-)

        • Knut Hildebrand sent a picture of the special tool earlier today. My take having looked at that picture is it would be highly unlikely I could make one with the equipment available on Dirona. I might be able to do it with the ability to heat and bend existing tools but I don’t have a torch on board.

          As you point out, I am an ex auto-mechanic and, for a fairly large class of faults, I probably would find a way to get it going.

      • Brian Smith says:

        James, I’m very interested in your “high quality oil that allows an oil change interval of 375 hours.” When you write the full article about this “sea change”, I hope you’ll include details about your choice of oil. Thanks!

        • Sure, I can explain the “high quality” oil point and the impact on change intervals. Deere like most high speed diesel manufacturers specifies a 250 hour change interval. But, they have +50 oil and, if you use both their +50 oil and their filter, they support a 375 hour change interval. The Deere +50 oil is ACEA-E9 (e.g. Delo 400) whereas the required oil is ECEA-E7. E7 oil is available pretty much everywhere but, E9 is often unavailable. I purchased E7 in South Africa and Papeete for example and currewntly only have E7 oil on the boat.

          I will include this in the blog. Thanks for the reminder.

  7. Tim Kaine says:

    Hey James

    With the care that you put into your engines and boat overall, waiting till you get to your destination for an oil change would do your engine no harm.

    However you state you have never done this feat underway, it is an undiscovered country for you that you could explore.

    I would still cast a vote to just keep running and wait. Either way fuel is still looking like a go. Awesome!


    • Good summary of my current take on this overall decision Tim: 1) the engine would be fine going 600 hours and 4 weeks on the oil change and 2) changing the oil would be a new eperience, allow us to test the wing in “real” use, and better prepare us for a real emergency at sea should one ever arise.

  8. Brett Griffin says:

    Hi James and Jennifer, another good article and I was wondering what you would do along these lines. Another boat with twin engines on a passage I read about actually stopped both engines mid Atlantic for no other reason than to experience the peace and quite and somewhat unusual situation out there.

    I don’t know what sort of oil change system you have but if you have an oil pump plumbed into the engine for pump out and pump in of the oil have you thought of the compromise of changing a percentage of the oil while the engine is still running. If you could accurately gauge the oil level and pumped it out down to close to the minimum specified operating level over a couple of changes most of the oil could be replaced or at least severely diluted with new oil.

    This leads me into another question I was going to ask. When flying long over water sectors in a pressurized aircraft the most limiting factor is often the much higher fuel flow and lower speed that would be encountered should we have a pressurization failure and have to fly at lower altitudes. In a similar way I was wondering what your fuel consumption was if your main engine failed and you had to proceed on your wing engine? I would imagine with the drag of the bigger prop your speed would be limited but have you checked long distance economy on the wing engine?

    On your current voyage you would have some off track diversions available should you have a problem but do you calculate a point of no return (PNR) or a single engine critical point (CP) on your long fuel critical legs?

    Hope you are all well and enjoying the trip,


    • With two engines there is no way I would even dream of shutting them both off. My version of “peacfull” and “close to nature” is the low pitched rumble of happy Deere diesel purring along. We’ll get our peace at anchorage :-).

      The incremental oil change using the oil change pump with the engine running isn’t as good as a full change or isn’t as efficient in that it’ll take more oil but, yes, it absolutely would work perfectly fine.

      Brett, asked a great question, have we tested the wing fuel economy to understand what it can deliver when dragging the main prop through the water. Excellent question. Many boaters never even test their wing in rough water. We have done that and know roughly what it can produce while maintaining safe output levels and not overheating it or otherwise putting the wing engine at work. But, we have never tested the fuel economy. The Deere is a very efficent, high pressure common rail engine built to Tier II emission standards which didn’t seem to negatively impact fuel economomy as much as Tier III seem to. The Deere is turbo charged and jacket water after cooled so is fairly efficient producing rough 19.8 HP/gal/hour. The wing engine is what you want in an emergency backupk engine: simple, mecahnical, under stressed, and not pushing technology in any way. The Deere puts out 266 HP fromm 6.8 liters whereas the wing puts out 40 hp from 2 liters. The wing efficiency is far lower — I’m guessing it will be down around 17 hp/gal/hour.

      The wing will burn more at 40 hp than the main engine. But, the main engine on this trip is running around 85 hp. I’m pretty sure what we will find is the wing will consume much more fuel at 40 hp than the main. Dragging the main prop will make it slightly worse but my intuition matches yours that this will only have a small impact.

      Net overall, the wing will burn more at 40hp, dragging the main prop will take marginally more, but the overall range of the boat at 40HP (or less for continuous operation) is really, really long and I’m pretty sure the increased efficiency of pushing the boat at only 4 kts will dominate and the boats effective range will be longer. I’m pretty sure fuel economy in good conditions won’t be an issue on the wing. In testing it can deliver 4.0+ kts in calm water for long periods. In these conditions it would be 4.0 kts. In rough conditions, I could see us having trouble making way at these lower power levels and, as that point approached fuel economy would become a factor. Current forecasts are for continued very good weather but one hates to count on a weather report being accurate.

      The challenge on this analysis is nobody has expereince running for long periods in rough water on only the wing engine so ther is very little information available. Much of what I have above is estimate rather than fact. You can never know everything on one of these trips :-).

  9. Jamie Bush says:

    What, another Jamie following Dirona? Say it’s not true!

    James, well written piece above – that is a dilemma. I think myself I would lean to not change. While the total service life may shorten, hearing that engine continue to hum away would be a nice trade off. The comments about jiffy lube are valid but your overuse would fall into the better kind of overuse if you could call it that as it wouldn’t have all the heat cycles and condensation associated with neglected engines – just use. But if you do change it, I thought Knut had a good idea to consider getting ‘relatively’ close to somewhere when you do change it. I’ll look forward to hearing what you decide! May the force be with you when you push the start button! :)

    • I 100% agree with your assesment Jamie. The oil was changed 2 weeks ago and if I don’t change it for two more weeks, it won’t likely materially change the lifetime of the engine. Modern high tolerance engines when combined with modern lube oils make bearing surfaces seldom the failure point that limits engine life.

      You also mentioned we don’t have the hot cold cycles and condensation from short trips that require short oil changes. The engine just sits at 180F water temp which is fine. Oil temp is perhaps a touch low at around 200F but it’s not bad either. So we don’t have the poor conditions from poor warming and short trips. But long low power runs are as big or even bigger a problem. At lower power levels, the rings don’t seat as well and there is more sooting. More carbon is pushed down into the oil and, paradoxicly, you want shorter periods between oil changes at low load rather than longer. Less likely but possible is oil dilution due to cool, incomplete burning causing unburned diesel to get into the oil

      Our Deere does a pretty good job of getting good heat in the water and oil at low load. There is no evidence of oil dilution during long runs at low load. But it does seem to bring soot into the oil — it’s oil is black very early in the change interval whereas previous engines have been able to do a 100 hours with barely colored oil. No big deal — all engines are different — but, at low power levels, there is likely more carbon in the oil than than there would be if run the same number of hours at higher output levels.

    • Jamie W says:

      It is true! (I’ll add an initial to be more distinct).

      I got to have a good old chat with James, sitting in Dirona’s engine room.

  10. Jamie says:

    You could just drain oil out the bottom while pouring it in at the same rate from the top. Think of it as like an engine on dialysis. ;)

    Slightly more seriously, I’ve heard of people using pipe wrenches to stop prop shafts on inactive engines from turning. It’d pay to remember to remove it before starting the engine though…

    • Jamie, you are absolutely correct and I have read about people doing this. I like your comparison to dialysis. Some boats consume so much oil that they end up doing this over long runs anyway just because they have to add a gallon every couple of hundred hours. But, our Deere burns nothing measurable so, using this technique, we would be using the oil pump to pump out a gallon at a time and then adding that in the top. It’s clearly not as good as a full oil change but way better than doing nothing and doesn’t bring the main engine shut down risk.

      Your pipe wrench idea would work perfectly well to stop shaft spin if the prop gets stuck deployed. Good suggestion.

      • Jamie W says:

        I was actually trying to be a smartarse with the dialysis! Don’t ruin it by telling me it’s a sensible idea! :p

        • Believe it or not Jamie, I actually have heard of situations where people have employed your trick to incrementally change the oil without shutting down the engine. It’s not my favorite approach but, if you are wiling to waste some oil, it’ll work fine.

  11. Knut Hildebrand says:

    Hi James,
    just a thought, you will pass a Brazilian Island with the name Fernando de Noronah (+/- 600nm), which has an airport, may be you could wait till you are close by and change the oil with running wing, and if the big rig isn’t coming back, you are going slowly to the anchorage, will send you a picture via normal mail of the with a pic of the tool, good luck and happy new year

    • Thanks for the research Knut. The change will come do in that rough area and, having tested the wing with long runs in moderate conditions like these, it does absolutely fine and can easily do 4.5 kts so not much risk by that measure.

      The more I think about this, the more I lean towards just do the maintenance that needs to be done when it needs to be done. Generally, the way we like to run the boat at sea is just to do everything the same as normal. We run the air conditioning, make water, do the laundry, and repair things on the boat as we usually do. On this approach, we usually arrive with the boat in as good shape and often better than when we left.

  12. Scott Smith says:

    Hi James,
    I was curious if you have a method of checking the oil level while underway such as a Murphy site glass?

    • That’s a great question Scott. What I used to do prior to this trip is just open the oil fill cap which has an integral dip stick on it, wipe it off, and redip. The correct oil level while the engine is running is around 2 to 3 quarts down — that’s the oil up in the engine still draining back. That technique has worked well for years but, on this trip, when I tried that the engine burped a slug of dirty old black oil out onto my clean ER floor. Annoying. I suspect what is happening is the engine is slightly over full. The engine takes 4 gallons of oil on a change. I buy full oil pails and use them all. Sometimes the pails are 4 gallons, sometimes they are 18 liters, and sometimes they are 20 liters. I’m currently using the last 20 liter container of Delo 400 from Australia. I suspect these “20 liter” containers are generously filled. A full 20 liter container is nominally the same as 4 quarts but technically it is actually 4.4 US gallons and, if the container was slightly over filled, it could be as much as a 1/2 gallon more than the full line.

      The primary risk of over filled oil is the mechanical parts swinging through the oil. This sounds like no big deal but actually is a big problem in that it can cause oil frothing which can reduce oil pressure and damage the engine. It also will substantially reduce the fuel economy. The oil pressure is bang on normal, the oil that burped out is not frothy, and the fuel economy is normal. So, I’m fine on the overfill but, consquently, can’t check the oil level in my usual way.

      Right now, I don’t have a means to check the oil level without making a substantial mess but I normally do.

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