Oil Change Schedule

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Me too...this last sample was the shortest interval yet ....85 hrs...others have ranged from 110 to 160 and the numbers are all the same with the recommendation to double the change interval.


I will let you know how the 85 hr number stacks up...if the same wear as the 160 hr interval...I can only guess it is saying that up to a certain point wear is exactly the same if the oil is maintaining the specified requirements.


Of course, using wear numbers from a Lehman compared to most diesels might be like comparing blood samples of a wooly mammoth to a triple crown winner....:D
 
O C Diver said:
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.
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Ted, I don't know what type of operations your charter boat engages in. I will assume that it sees much higher usage than most cruisers do each year. In that situation, I can see trying to extend the life of your engine by a significant amount in the hopes to avoid, or delay a repower.

OTOH, how many folks here are likely to "wear out" a diesel engine? I really don't know. You asked a rhetorical question, but I would like to ask a real question: What is the life expectancy of say a Cummins 5.9 QSB engine? It, and its sisters are very common in the typical trawler. Second question that is harder to answer I imagine, is by what factor would increasing oil change frequency also increase engine life?

Maybe a related question is how many folks have had to repower recreational trawler because the engine had simply worn out?

Maybe the same question should be asked of the ubiquitous Norther Lights 6kw or 8kw genset?
 
dhays said:
Ted, I don't know what type of operations your charter boat engages in. I will assume that it sees much higher usage than most cruisers do each year. In that situation, I can see trying to extend the life of your engine by a significant amount in the hopes to avoid, or delay a repower.

OTOH, how many folks here are likely to "wear out" a diesel engine? I really don't know. You asked a rhetorical question, but I would like to ask a real question: What is the life expectancy of say a Cummins 5.9 QSB engine? It, and its sisters are very common in the typical trawler. Second question that is harder to answer I imagine, is by what factor would increasing oil change frequency also increase engine life?

Maybe a related question is how many folks have had to repower recreational trawler because the engine had simply worn out?

Maybe the same question should be asked of the ubiquitous Norther Lights 6kw or 8kw genset?
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The Cummins in my Dodge pickup is a B series engine. In boating terms it's a 6BT 220 HP. The turbo isn't liquid cooled like on a marine engine. Mine has 410,000 miles on it which roughly equals 8,200 hours. Haven't changed anything inside the engine or the turbo. Goes 5,000 miles between oil changes doesn't use any oil. While this motor has a great track record in Dodge pickups, 400,000 is probably in the top 10% category and even rarer to have the original turbo. While I don't drive my truck hard, I credit frequent oil changes as part of the success. I just hope Dodge keeps making parts for the truck. :rolleyes:

Can't really answer your second question. I have found that changing fluids more frequently also extends the life of ancillary equipment. My pickup has the original transmission, differential, power steering pump. Most mechanics would tell you that stuff doesn't last that long. I believe the increased life can at least partly be a tributed to changing lubrication oils.

I doubt any of us are going to wear out a new diesel in a recreational boat. That being said, if you have a high output motor such as a 375 HP Cummins B, you need to do everything you can to reduce heat and wear to get a reasonable life out of them. Think it's very tough to say what the leading causes of engine failures in boats are as many times it may be how the previous owner used or abused it.

One day when I sell my trawler, I'm hoping the prospective buyer will look at my maintenance records and think, "nothing to worry about here".

Ted
 
O C Diver said:
Think it's very tough to say what the leading causes of engine failures in boats are as many times it may be how the previous owner used or abused it.
Ted
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There are direct and indirect charges. You won't see a failure and be able to then say, "not changing oil caused this." However, I believe well maintained will outlast less well maintained. I do believe deterioration of oil and failure to change as needed can definitely contribute to failure of various parts.

I ran into similar in business. I could never prove the benefit of routine maintenance as I sure wasn't going to run a test, half on it and half off. However, I did inherently believe it extended the life of equipment and led to fewer problems.

Now, determining what is necessary can be done many ways. I prefer to leave the proper scheduling of maintenance to the manufacturer. I then do believe in analysis as well. But we do now and will continue to change oil and do all other service no less frequently than the manufacturer recommends.

We also prefer to do the majority of oil changes and routine maintenance at home and so do what we are approaching the schedule for at home prior to leaving on extended cruises. That is definitely not possible at all times.

Two other factors in our situation. One is to preserve the warranty on all equipment. The other is for potential resell. We do want to be able to present well functioning equipment but also a history that shows all maintenance done as recommended.

We do have fairly new equipment and have experienced no problems. I have put many years and hours on boats with no issues. Can I prove that following service recommendations has contributed to the lack of trouble? No, I can't. Do I believe it? Yes, I do, so will continue to do as I have. I also know that it's a lot less costly to prevent problems than to fix them.

Now, I'm not encouraging anyone to go to shorter schedules than the manufacturer recommends. I see no benefit to that. We only do shorter because of impending cruising. As to extending the time between changes and getting oil analysis. I don't want to ever have an analysis that shows degradation so I won't go beyond the recommended schedule. I'm not going to push it until it shows a problem.
 
The last thing to wear out of in these boats is the motor. In 30-40 years good luck finding the parts that need replaced. Most important thing in life do what makes you happy!
 
"The last thing to wear out of in these boats is the motor. In 30-40 years good luck finding the parts that need replaced."

Perhaps with farm implement motors or marinized taxi or pickup truck engines,

DETROIT DIESEL does just fine with WWII vintage parts.
 
I said I would get back after my 85 hour interval came in...planning on changing after I get to Charleston...maybe 40 hrs from now but will hold off on a test sample till summer after another 120 hrs past Charleston.

Blackstone comments on sample...

For the first time in almost a year, the viscosity is in the proper range for 30-weight Shell Rotella T.
We didn't consider the slightly lower readings for the past several reports to be problems, but they were
keeping us from giving this engine perfect reports -- but that's not the case here. Wear metals continue to
look great, and there are no signs of harmful contaminants or other problems, so this is a flawless,
highlight-free report at 2,107 hours. The shorter run is why iron is lower than usual, but that's fine -- you
could leave this oil in use a while longer if you want.
 
Volvo Penta recommend oil changes for my engines as 100 hrs or annually.

As luck would have it I tend to do around 100 hrs use a year so it always gets changed about bang on the manufacturers recommended interval. And I know it was done by the previous owner who was meticulous about this. So the engines are in really good condition mechanically.

But there's more to changing the oil because of perceived wear rates.
To me it's more about the fact that the products of diesel combustion are acidic as well as abrasive. The additives in the oil compensate for this (TBN number and such). But clearly they deteriorate with use as has been mentioned above.
The most important thing is not just the hours run but the environment.

I always change my oil in the autumn, just before the boat gets left for several months over the winter. It's essential it has fresh oil in it for this period because if it had, for want of a better expression stale oil (used) the acidic components can eat into the bearing shells whilst it's sitting stationary over the winter, potentially leading to early (or earlier) bearing wear. The wear factor isn't necessarily the only major problem - it's the acidity and other factors.

I wouldn't have the slightest problem doing 200-250 hours in a season before changing the oil (although I would be monitoring its condition closely via feel on the dipstick) because I can tell that at 100 hours it still has plenty of life left in it. It's clean and only slightly discoloured. But it would definitely get changed before laying up for the winter, as it has after seasons when I've only done 75 hours.

It's not just about hours run, it's about changing it before laying up
 
An interesting question is should the newest best modern lube oil or an old standby be used?

As I understand it CD is most common for old (non DD ) engines and today CK? or such, is what is required for modern big engines.

The difference is in the additive package ,far more detergent is in the new oil.

This is because the Air Police require a cleaner exhaust than what goes in the intake in many locations.

Lowering internal temps (at a great cost in efficiency) is done with EGR, and it is this exhaust fed back into the engine that requires fantastic detergents to control.

Perhaps good old single wt. CD oil would have more OIL in the "oil" and give our antiques their best service life?
 
I am in the "oil probably doesn't matter too much" crowd.

Yes decent oil....yes decent change intervals...

But as someone quoted Tony Athens and loads of other talented engine guys and operators with tons of experience....there are so few engine failures that are directly related to oil and oil changes that it just doesn't strike me as something to bother me.

I test the oil as much for an impending failure by antifreeze, or water getting in or a particular part failing rapidly....IOW...early warning so I can plan a place of repair rather than nowheresville.

So if you think your engine life will be extended to the day after you sell your boat by using better oil or changing it every day...have at it.

I am guessing I will be like everyone else I know with engine issues . They arise from an operational issue or a component that fails and causes enough damage to do a rebuild/replace. Wearing out my engine from cheaper oil or letting it go to recommended intervals and even beyond occasionally isn't a thought that ever enters my mind.

Are there examples? Sure someone can come up with them...but I probably know more people whose boats have been struck by lightning.
 
psneeld said:
Are there examples? Sure someone can come up with them...but I probably know more people whose boats have been struck by lightning.
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I have skippered a boat when it was struck by lightning. I've never skippered a boat when the engine failed due to old oil.

Just sayin' :)

Richard
 
O C Diver said:
I'm looking for below "normal wear numbers ". ;)

Ted
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If I was running a commercial boat I'd install bypass oil filters and run synthetic oil while doing my first oil analysis at the manufacturers stated oil change interval. Then I'd do subsequent analysis every 100 hours there after. I'd just change the filters at the normal oil change interval.

I've done that on gensets and gone 3 or more times the normal change interval.

I've used the Amsoil bypass filters. https://www.amsoil.com/shop/by-product/filters-and-by-pass-systems/by-pass/filters-and-mounts/

There is also a system that continually changes your oil as the engine is running and mixes the old oil into your diesel fuel so you just burn it up.

Engineered Machined Products : DNCO Oil Management System
 
Thank you Richard...I can add another to my list....:D

Fortunately it is only a handful of people and none have been hurt...:thumb:
 
The main reason we change oil is to get rid of the carbon as a combustion by-product that gets into the oil. The black in oil is the carbon and diesel engines accumulate much more so than gas engines.

The oil gets balck w carbon very quickly in diesels. Many "schedules" have been presented here from just a few hours to hundreds of hours. My take on it is that the wide range of oil changing times represent a wide grey area that makes me think "why get religious about 100hrs, 250hrs" or whatever. Oil dosn't suddenly get black w carbon but in a very idealistic world one should change oil every time the boat was used. And then there's some that never change their oil .. and every scenairo in-between.

I change my oil about twice a year. Usually spring and fall. But I've done it more than that at times. The reasons to change oil vary quite a lot so why stick to some ridgid schedule most likely dictated by someone else and not relavant to your own usage? There's many "experts" w many different change schedules.

I do agree w FF that oil should be changed hot .. right after the boat has been run at cruise speed for a time. And if a good time happend by and it was not on my schedule I may just change it. Dosn't take much time on my boat and dosn't cost very much. An in-between oil change like this dosn't (IMO) require a filter change either making it faster and less expensive yet. And most of the carbon is removed from the oil. A win win .. no downside.
 
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We keep talking about engines failing because of the oil used. The issue isn't failure, it's wear over a period of time. For most, the usage is so low, that getting a long term picture and having something else to compare it to is impossible. Let's say engine requires a rebuild at 20,000 hours. We have no way of knowing whether had we used a different oil or changed more frequently would it have gone 22,000 hours or had we gone the other way would it have only gone 18,000 hours. I most definitely am not an expert on oil and don't intend to be. Therefore, I use what the engine manufacturer recommends. I'm willing to concede that they are more expert on their engines than I am.
 
Show me a boat with 10000 hrs on it and it is worn out and at 20000 hrs you can junk it.
 
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The original owner of my boat used Sears 30wt.

Since I could not find that switched her to Shell Rotella 30wt. No changes noted.
 
6 knots at 10000 hrs you will have circumnavigated the world twice and for some boats 100 oil change. Wow impressive for 2 years.
 
funangler said:
6 knots at 10000 hrs you will have circumnavigated the world twice and for some boats 100 oil change. Wow impressive for 2 years.
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I doubt Bill was thinking 6 knots. He's not a 6 knot kind of guy.
 
caltexflanc said:
Just for the record, here are the articles Tony Athens has posted on his web site regarding this subject. So scratch him of the "loads" of unknown mechanics list
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Scratch me from one who cares what "loads" of mechanics say and from one who goes to a forum or elsewhere to get an opinion on something that is covered in an engine manual and/or other documents from the manufacturer.

I consider my engine manufacturer to be the expert regarding the engine.

I think the documents you linked to are excellent. The only caveat I would use is that the Service Bulletin is dated 2007 and I would want a more recent one if available and definitely a more recent one for a newer engine.
 
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