Engine and gear oil change cycle

[CaptBud]

Oil change frequency ? fact or fiction ? My frequency of oil and filter change has boiled down to "fall and end of season" We all know that used oil contains metal particles ,soot, depleted additives, acids, a whole host of contaminants.
My estimate is that the average boater, slow boats in particular, probaebly put one hundred hours or less which at trawler speeds averaging six to seven knots amounts to 600 to 700 miles per season, this is in my estimation generous.
Should we take a closer look at the habit and frequency of changing oil so often, i.e. at the end of each season? especially considering the actual operating cycle of our gears.
I'm not looking to be pummeled by accusations of stupidity, I'm only interested in starting an intelligent and sincere conversation.

 

[CaptBud]

The title should read " Engine and Gear Oil Change Cycle"

 

[O C Diver]

I do mine every 500 engine hours (3,000 to 3,500 miles) or annually. Mine holds 1 gallon and is hooked to the oil change pump. Gear oil is too easy and cheap not to change regularly. I do oil analysis every time I change it. Nice to know how everything is wearing and if the gear cooler is starting to fail (water or sodium [salt from brackish or salt water]).

Ted

 

[Comodave]

I edited the title for you.

On our last boat we had Lehmans and the recommended oil change was 250 hours so that is what I did. I also did the transmission oil at the same time. Our current boat had the oil changed the day before we bought it so I have not done it yet.

 

[O C Diver]

I do mine every 500 engine hours (3,000 to 3,500 miles) or annually. Mine holds 1 gallon and is hooked to the oil change pump. Gear oil is too easy and cheap not to change regularly. I do oil analysis every time I change it. Nice to know how everything is wearing and if the gear cooler is starting to fail (water or sodium [salt from brackish or salt water]).

Ted

I misread the question. Engine oil is changed every 100 hours. Gear oil is changed every 500 hours. Oil analysis with all changes.

Ted

 

[Comodave]

Ted, i was surprised that you went 500 hours on the main engine before an oil change, glad for the clarification.

 

[LovetoBoat]

Mine holds 1 gallon and is hooked to the oil change pump. Ted

So I want to ask - what size/type engine do you have? I have a 500hp Cummins and it takes 6 gallons.

I assumed most took more oil - my cars and trucks take between 5 and 6 quarts and I was surprised to see 1 gallon.


Thanks

 

[firehoser75]

I also changed my oil and gear oil either at fall layup or at 200 hours (for the engine only, gear waited until fall) whichever came first. Oil testing done annually as well for the reasons Ted talked about. Usually the hours between changes was below the 200 mark.
My thoughts are for the small costs (I do it myself) it is cheap insurance and I do not leave the engine sitting with "contaminated" oil in it over the winter. For me the saving I could have by only following the recommended hours would be very minimal, so not worth it to me.

 

[fryedaze]

I misread the question. Engine oil is changed every 100 hours. Gear oil is changed every 500 hours. Oil analysis with all changes.



Ted

100 hrs, the next owner will get a gift. I thought JDs we're 250 hrs and 300 hrs if you use their +50 oil.

 

[Comodave]

So I want to ask - what size/type engine do you have? I have a 500hp Cummins and it takes 6 gallons.

I assumed most took more oil - my cars and trucks take between 5 and 6 quarts and I was surprised to see 1 gallon.


Thanks

I think he was referring to the transmission.

 

[O C Diver]

So I want to ask - what size/type engine do you have? I have a 500hp Cummins and it takes 6 gallons.

I assumed most took more oil - my cars and trucks take between 5 and 6 quarts and I was surprised to see 1 gallon.


Thanks

Ok, so I have a John Deere 4045 135 HP and typically run it between 1.5 and 2.0 GPH (30 to 40 HP). It holds 3.4 gallons of oil. I experimented with extended oil changes and started developing significant (IMO) wear metals.

I have another diesel engine. My 2002 Dodge pickup has a Cummins 6BT 220 HP. It has 512,000 miles (over 10,000 hours) on it. Other than adjusting valves the block hasn't been entered / repaired. The manual transmission gets regular oil changes and is on its fourth clutch. Clearly regular oil changes work. The owners manual recommends oil changes every 5,000 miles. That equals about 100 hours of my average driving. It holds 3 gallons of oil. My average fuel consumption is about 2.4 GPH.

Based on the engines being fairly comparable, I decided 100 hours made sense. Wear metals are really low.

On one of my recent truck oil analysis from Blackstone they wrote:

TED: We're starting to think you're trying to pull a fast one on old Blackstone, and you're sending us the
same oil over and over again only pretending that it's different fills. But seriously, this is the steadiest wear
you could ask for, and there's no question about the internal health of this truck's engine. This report looks
just like the last, which looked just like the last, which looked just like the last one before that. You've got a
good thing going here, so just keep up the great work!

Ted

 

[O C Diver]

100 hrs, the next owner will get a gift. I thought JDs we're 250 hrs and 300 hrs if you use their +50 oil.

Depending on the oil, JD recommends out to 250 hours.

I'm guessing when I sell the boat, the buyer will smile when he sees oil analysis for every engine, transmission, and generator oil change. BTW, I now have 3,700 hours on the engine.

Ted

 

[fryedaze]

Depending on the oil, JD recommends out to 250 hours.



I'm guessing when I sell the boat, the buyer will smile when he sees oil analysis for every engine, transmission, and generator oil change. BTW, I now have 3,700 hours on the engine.



Ted

Holy cow, it has taken me 11 years to get 3700 hrs. Your summer cruising will keep you ahead of me. I sit between June and Sept.

 

[Mako]

I've always just followed the manufacturer's recommendations. If I recall right, my Jimmies and Allison gear were every 200 hours (roughly, it's been a few years) and my Mercury 4-stroke was 50 hours. The easiest one of all is my Merc 2-stroke!

 

[klee wyck]

Ok, so I have a John Deere 4045 135 HP and typically run it between 1.5 and 2.0 GPH (30 to 40 HP). It holds 3.4 gallons of oil. I experimented with extended oil changes and started developing significant (IMO) wear metals.


If wear metals are generated at the same rate per hour of run time, would not the wear metal analysis always be lower in 100 hour oil than in 250 hour oil? And, does that matter?

 

[Jeff F]

Depending on the oil, JD recommends out to 250 hours.




Ted

I have the same motor as you and JD extends recommended oil change intervals to 375 hours with specified oil filter and oil. I've done the last couple of changes at around 350 hours.

But to the OP's point, if I'm hauling for the winter in eastern Canada I'll change the oil just before coming out to have clean fresh oil for the winter layup. On my sailboat that doesn't accumulate many engine hours it's once a year in the fall.

 

[O C Diver]

Ok, so I have a John Deere 4045 135 HP and typically run it between 1.5 and 2.0 GPH (30 to 40 HP). It holds 3.4 gallons of oil. I experimented with extended oil changes and started developing significant (IMO) wear metals.


If wear metals are generated at the same rate per hour of run time, would not the wear metal analysis always be lower in 100 hour oil than in 250 hour oil? And, does that matter?

From my last oil analysis:
Aluminum is 1 PPM
Iron is 4 PPM and trending lower
No other measurable wear metals

As to whether it matters:
I've never heard anyone make the claim that engine oil and filtration were changed to often. Plenty of failures from the opposite. The rest is opinion. IMO, getting the wear metal particles and carbon out of the oil can only benefit the engine.

I considered other options.
Buying a centrifuge wasn't realistic compared to the cost of oil changes.
Adding a secondary oil filtration was strongly considered. https://www.kleenoilusa.com/

Currently an oil change costs me <$60, cheap insurance.

Ted

 

[FF]

"IMO, getting the wear metal particles and carbon out of the oil can only benefit the engine."

Getting the detergent package refreshed and the acid from combustion removed cant hurt!

 

[backinblue]

Same as the OP, I do Engine and generator oil and filters at the end of the season before winter layup. I also probably avg in the range of 100 hours, much less on the gen. I would not worry if I put on more hours in a given season but defintiely want fresh oil at the end. Generator could probably go every other year, but I do it each fall anyway. I have not done a gear oil change yet. I'll check my manuals but i don't think it's due yet and it looks very clean, like baby oil.

 

[O C Diver]

I have not done a gear oil change yet. I'll check my manuals but i don't think it's due yet and it looks very clean, like baby oil.

Gear oil isn't supposed to change color like engine oil as there's no carbon from combustion being added.

Gear oil breaks down as a function of shearing the molecules. Simply, over time, lubricity (yes that's actually a word) is lost and the oil doesn't lubricate as well. Secondly, transmissions generate wear metals from clutch plates and other parts.

If you doubt me, after running the boat for a few hours, draw an oil sample while the transmission is still warm and send it off for oil analysis. You will be surprised at the amount of wear metals.

Changing my transmission oil is <$14, cheap insurance.

Ted

 

[catalinajack]

"IMO, getting the wear metal particles and carbon out of the oil can only benefit the engine."

Getting the detergent package refreshed and the acid from combustion removed cant hurt!

There is no acid in oil until the neutralizers are exhausted. The Total Base Number (TBN) is the measure. Diesel oils start out with a TBN of 10 - 12. Oil with a TBN down to "two" is still viable but not for long. I just changed the oil on my diesel pickup after 660 hours. The TBN was "12" when fresh, down to "5" at 660 hours. The oil analysis report came back stating that the oil was still viable but to test again at 150 hours more. I chose to change the oil at that point.

The idea that oil must be changed at layup so as to not have the engine bathed in acidic oil all winter is pure fallacy. I find it interesting that so many folks pay good money for oil analyses but do not consider the TBN and/or whether the oil continues to be perfectly good for continued use. I attribute this to the fact that Blackstone charges extra for TBN analysis.

 

[firehoser75]

I agree with Ted (about regular oil changes not necessarily the interval) especially for the transmission. Tranny oil on our boat never changed colour or appearance. It always "looked like new oil". If memory serves, the manufacturer recommended changes every 500 hours. I never put 500 hours on in a year, so I changed it annually in the late fall. For the engine, I followed the manufacturer's recommendations which meant that I changed annually (in most years) except the one year I put on about 280 hours so I changed at (just less than) 200 hours and again in the late fall.
To me, even though I did oil analysis each year, I just did not see the value in trying to extend past the OEM recommendations by spending as much as an oil change on extra analysis (well almost as much). It just made more sense to change it before fall layup usually at about the 120-150 hour mark.
Agree with Ted: Cheap insurance. I have always been told to follow OEM and to never exceed the recommendations (requirements for warranty). I have also been told, read, etc. that changing way more often is not necessary and is just overkill.
However, with a marine transmission and a built in oil change pump, it just made sense to change it annually at the same time as the engine oil. Literally took about 10 extra minutes (most of that time was the refill by hand not pump).

 

[Bacchus]

There is no acid in oil until the neutralizers are exhausted. The Total Base Number (TBN) is the measure. Diesel oils start out with a TBN of 10 - 12. Oil with a TBN down to "two" is still viable but not for long. I just changed the oil on my diesel pickup after 660 hours. The TBN was "12" when fresh, down to "5" at 660 hours. The oil analysis report came back stating that the oil was still viable but to test again at 150 hours more. I chose to change the oil at that point.

The idea that oil must be changed at layup so as to not have the engine bathed in acidic oil all winter is pure fallacy. I find it interesting that so many folks pay good money for oil analyses but do not consider the TBN and/or whether the oil continues to be perfectly good for continued use. I attribute this to the fact that Blackstone charges extra for TBN analysis.

This echos my thoughts... well stated.
I also believe the oft stated rationale for changing to avoid leaving acidic oil to sit in an engine is pure myth and can't be supported with any factual evidence... but I'm open if anyone can produce their oil analysis that shows an acidic result.
It would be interesting to see all of those that do analysis post their results for others to see how "acidic" the analysis shows.
I also find it curious why some will point to particulate results and believe the test results while they ignore the baseic / acidic analysis... why? Don't believe it? Believe particulate levels override any acid/ base?
Please explain why they do analysis but ignore the recommendations? Does it make sense to only consider heat exchanger degradation?

 

[rslifkin]

For the transmissions, I should really be better about paying attention to when I change those. I am planning to do them in the spring though. For my Velvet Drives (72C), the manufacturer suggests a change every year for pleasure boats, or every 1000 hours for work boats. I know mine have never been changed every year, but it's always been well before 1000 hours. They also say that if you ever get a transmission overtemp alarm, change the fluid immediately.

For my engines, the recommendation is every 100 hours. Typically I'm a bit short of 100 hours by the end of the season, so I just change at the end of the season. If we run more than that, I'll change at 100 hours, as I haven't done oil analysis on these engines, so I have nothing to indicate how well the oil will hold up beyond the 100 hour mark. Generator gets the same treatment as the engines, although I'm a little more conservative there, as the thing doesn't have an oil filter.

Changes for my stuff aren't a big deal, as a change on both engines and the generator is only about 3.5 gallons of oil total (supposedly the engines hold 7 quarts, but a typical change is about 5.5, generator takes a bit over 3 quarts). Transmissions are a little under 3 quarts each.


On the acidic oil topic, all oils have an ability to buffer acids. This is measured as the TBN. When that gets close to depleted, then you have to worry about acidic oil. But in general, if the engine will be sitting for a while, it's a safer bet to change the oil, as fresh stuff with higher TBN and less contaminants in in it will have less risk of causing corrosion, etc. especially if you get any condensation inside the engine. That said, if I have a car or something that's going to be sitting and the oil in it is fairly new (usage wise), I won't bother changing it before storage and will only worry about it once the oil is 2 - 3 years old. But if the oil has some more use under its belt, then I'll change it before storage (especially if the engine won't be sitting in a climate controlled environment where condensation is a minimal risk).

 

[firehoser75]

Bacchus (and others), I don't discredit anything you are saying. However, in my opinion, there are other reasons for oil monitoring than trying to extend the time between changes and/or "get the most" out of it.
Oil analysis can be used to monitor overall engine condition (wear) over time to look for trends and areas of concern. Also, having records of oil analysis (as well as full maintenance records) can help show to a future buyer the over all care given and condition of the mechanical system, potentially making the boat easier to sell (comparatively speaking) and possibly for a better price.
Also to me, on the scale of boat costs, oil changes are cheap and easy.
Another case of "to each his own" and no one "right answer" (except just extending the time without any evidence (testing) to ensure it is still doing it's job adequately).

 

[SteveK]

I used to do an annual change from the old school days. Since getting annual oil sample testing and being told leave it alone I stopped. I did however change the filters and that was to make me feel better about it.

 

[backinblue]

Gear oil isn't supposed to change color like engine oil as there's no carbon from combustion being added.

Gear oil breaks down as a function of shearing the molecules. Simply, over time, lubricity (yes that's actually a word) is lost and the oil doesn't lubricate as well. Secondly, transmissions generate wear metals from clutch plates and other parts.

If you doubt me, after running the boat for a few hours, draw an oil sample while the transmission is still warm and send it off for oil analysis. You will be surprised at the amount of wear metals.

Changing my transmission oil is <$14, cheap insurance.

Ted

Thanks. Like I said I'll check the manual, but I have it on my short list of things to do.

 

[Simi 60]

So I want to ask - what size/type engine do you have? I have a 500hp Cummins and it takes 6 gallons.

I assumed most took more oil - my cars and trucks take between 5 and 6 quarts and I was surprised to see 1 gallon.


Thanks

Ours has a 350hp Cummins
And the gearbox takes around 10 gallons

Recommended is 1000 hours /6 mths but I reckon that'd be for boats actually working hard, pulling nets, boats etc
Oil is near two years now and as clear as the day it went in.

 

[fgarriso]

Oil is the cheapest parts you can buy for you engine(s).

I change our every 100 hours, cheap insurance.

 

[Simi 60]

Oil is the cheapest parts you can buy for you engine(s).

I change our every 100 hours, cheap insurance.

I would have thought on a boat your size the engines would be a 250 hour minimum change, more if working on weight of fuel.

Even little B series Cummins get.....

Turbocharged B3.3 engines require an oil change at 350-hour/3-month intervals, while naturally aspirated models can go 500 hours or 6 months between oil changes
https://www.cummins.com/engines/b33-tier-4-interim?application=Agriculture&title_2=&v=111&page=1