Oil change interval with marine diesels

[mocruising]

Recently rafted up with a few boats and we got chatting about oil change intervals. I have a Volvo Penta (VP) TAMD 31 S in the book it says change the filter every 100 hours but no mention of what hours to change the oil. I have always done the two together at 100. The boat next door had a naturally aspirated VP and his book said 500 hours. The other side was another VP with a turbo charger and his book said oil and filter every 200 hours. The next chap along had a Yanmar with a turbo charger and his book said 200 hours for oil and filter. Why the differences for similar marine diesels engines with turbo chargers. I can understand the extended interval for the naturally aspirated engine but 500% longer!!! (100 hours as opposed to 500 hours)

 

[PeterGibbs]

Recently rafted up with a few boats and we got chatting about oil change intervals. I have a Volvo Penta (VP) TAMD 31 S in the book it says change the filter every 100 hours but no mention of what hours to change the oil. I have always done the two together at 100. The boat next door had a naturally aspirated VP and his book said 500 hours. The other side was another VP with a turbo charger and his book said oil and filter every 200 hours. The next chap along had a Yanmar with a turbo charger and his book said 200 hours for oil and filter. Why the differences for similar marine diesels engines with turbo chargers. I can understand the extended interval for the naturally aspirated engine but 500% longer!!! (100 hours as opposed to 500 hours)

The synthetic oils unquestionably offer longer service intervals because they hold their structure longer. I change the oil in my S leg every two years - perfectly sound practice, it seems (after 12 seasons' experience)

But the sump oil is regular mineral, not expensive, and come season's end it looks pretty cruddy. I do quite a lot more than 100 hours most seasons on the donk, so chuck it and the filters out before the winter layup. This, too, seems good practice - not related or conditioned by hours.

Years ago when debating this with an engineer, he gave me what seems the best advice: within the season don't bother with oil and oil filter changes - if you want to up the integrity of your rig, chuck out the fuel filters with great regularity. I go with this.

PWG

 

[Ric]

Ironically I just logged into this site to ask exactly the same question myself.

I have a Volvo MD1010 19hp, and the Volvo salesman recommend changing oil & filter every 100 hours or every year, whichever happens earlier. After I cheekily pointed out that it was impossible to know when 100 hours occured, as the LCD display breaks every 50 hours or so, I went on to ask him why the intervals are so short. I pointed out to him that my car (Mercedes Diesel) has on-board diagnostics which determine when oil changes need to be done, and this occurs every 25000km or so, which is equivalent to about three years and 500hours of driving.

His answers were not at all convincing. He claimed that the oil breaks down if older than a year (how comes not in my Mercedes -exactly the same oil?), he then went on to claim that the stresses in my boat engine were higher than in the Mercedes. I pointed out that this was also baloney - my Merc revs to around 6500rpm, continually accerlates and decelerates, and produces 150hp - compared to puny 19hp of my Volvo, which trundles along steadily at about 2200rpm and is never revved beyond 3000rpm. He went off muttering about some important meeting at this point.

 

[Chris_Robb]

Ironically I just logged into this site to ask exactly the same question myself.

I have a Volvo MD1010 19hp, and the Volvo salesman recommend changing oil & filter every 100 hours or every year, whichever happens earlier. After I cheekily pointed out that it was impossible to know when 100 hours occured, as the LCD display breaks every 50 hours or so, I went on to ask him why the intervals are so short. I pointed out to him that my car (Mercedes Diesel) has on-board diagnostics which determine when oil changes need to be done, and this occurs every 25000km or so, which is equivalent to about three years and 500hours of driving.

His answers were not at all convincing. He claimed that the oil breaks down if older than a year (how comes not in my Mercedes -exactly the same oil?), he then went on to claim that the stresses in my boat engine were higher than in the Mercedes. I pointed out that this was also baloney - my Merc revs to around 6500rpm, continually accerlates and decelerates, and produces 150hp - compared to puny 19hp of my Volvo, which trundles along steadily at about 2200rpm and is never revved beyond 3000rpm. He went off muttering about some important meeting at this point.

Your VP is old technology, runs at up to only 70degrees C, uses basic mineral oil and burns high sulphur red diesel. So the oil gets very acidic, with all the bi products of combustion. So change at 100 hours is absolutely correct. Bit do not feed it with high quality oils , only mineral oils....

 

[Ric]

Your VP is old technology, runs at up to only 70degrees C, uses basic mineral oil and burns high sulphur red diesel. So the oil gets very acidic, with all the bi products of combustion. So change at 100 hours is absolutely correct. Bit do not feed it with high quality oils , only mineral oils....

No, I sail in the Med - no red diesel - it burns exactly the same diesel as my car burns, and it has the same 15W40 as my car.

 

[PerformanceSailor]

Clean oil = happy diesel

An experienced diesel mechanic friend recommends an oil and filter change once a season. Fall slightly preferred, unless you intend to change it again in the spring. (Good to have fresh oil throughout the engine during the cold months when it sits for several months at a time.)

The oil itself may seem OK, but acids and stuff can contaminate it over the months. Some of the additives can break down, also.

I use a multigrade, Delo 400LE, 15W-40. I do not know what the prior owner was using when we bought this boat in '94, with about 1000 hours on the 23 hp Universal diesel, but we now have approx. 2000 hrs on it. Never burns oil and seems to run fine.

As my friend says, good oil is the cheapest insurance and maintenance you can do for your small diesel. That, and always run it under load at full cruising rpm's and limit time idling.

Sidebar: I know some owners that do change their oil very 50 hours, but have not heard of any measurable advantage in doing so.

 

[reeac]

Ironically I just logged into this site to ask exactly the same question myself.

I have a Volvo MD1010 19hp, and the Volvo salesman recommend changing oil & filter every 100 hours or every year, whichever happens earlier. After I cheekily pointed out that it was impossible to know when 100 hours occured, as the LCD display breaks every 50 hours or so, I went on to ask him why the intervals are so short. I pointed out to him that my car (Mercedes Diesel) has on-board diagnostics which determine when oil changes need to be done, and this occurs every 25000km or so, which is equivalent to about three years and 500hours of driving.

His answers were not at all convincing. He claimed that the oil breaks down if older than a year (how comes not in my Mercedes -exactly the same oil?), he then went on to claim that the stresses in my boat engine were higher than in the Mercedes. I pointed out that this was also baloney - my Merc revs to around 6500rpm, continually accerlates and decelerates, and produces 150hp - compared to puny 19hp of my Volvo, which trundles along steadily at about 2200rpm and is never revved beyond 3000rpm. He went off muttering about some important meeting at this point.

Are you comparing like with like? If your car can rev. to 6500 rpm. I should think that its petrol not diesel and petrol engines dump less pollutants into their oil - hence less frequent changes.

 

[Chris_Robb]

Are you comparing like with like? If your car can rev. to 6500 rpm. I should think that its petrol not diesel and petrol engines dump less pollutants into their oil - hence less frequent changes.

Your car also runs at a much higher temperature and synthetics apparently don't work properly below the operational temperature. I note that you are in the Med, so am I , but the oil still gets polluted by the combustion bi-products, which I think is partly the result of the much lowers manufacturing tolerances of the old engines. My car diesel engine oil stays golden for quite some time (its done 230,000 miles) My VP oil looks thin and weedy after about 2 weeks!

 

[SolentPhill]

something like oil is important and when you work it out its not an expensive bit of important food for the engine, if we were talking thousands to change then yes make it last, but for what a boat and or engine costs why stretch it, cheap oil is not the best and filters left on too long in salty air is not good.

if you like your boat then yearly is a minimum even for piece of mind.

 

[Dockhead]

Yanmar recommends 250 hours or one year, whichever comes first, oil & filter change for most of their engines. I don't think that one size fits all, where hours are concerned. In a sailboat where you use the donk for short periods getting out of harbour, and then at low revs, much more **** gets into the oil per hour, than on say a water taxi or commercial fish boat where you run for hours and hours at a time with a decent load.

Therefore, I think that the 100 hours habit which many people have is sound.

Probably a certain number of times per year is more sound practice, than every certain number of hours.

I generally do mine (on a Yanmar 4JH3HTE turbodiesel, 100 hp) twice a year. I usually use the donk about 300 hours per year over 70 to 80 days at sea, so that usually puts me at 150 hours every oil change. If I use the engine a lot more, then it will be more hours between changes, but that's ok in my book, since that would be the result of more longer passages under motor so less burdening of the oil per hour run. If it use it less, then it will be closer to the 100 hour rule, which is right when the engine has been used for shorter intervals every time. So for me, I figure a time interval for oil change is better than an hours run interval.

If you lay up your boat over winter, you don't want your engine to be sitting there with acid in the oil, or lots of particulates which might come out of suspension during the lay up to clog up your oil galleries. So in any case always, always, always change your oil and filter before laying up.

As someone said, don't waste your money with synthetic oil. Your oil will be full of particulate matter and acid long before the long-chain molecules start to break down.

Be more careful with changing oil in a turbocharged engine than a naturally aspirated one. Turbochargers run at high speeds and are more sensitive to lubrication than the engine itself. Common knowledge but worth repeating.

 

[Marsupial]

Ironically I just logged into this site to ask exactly the same question myself.

I have a Volvo MD1010 19hp, and the Volvo salesman recommend changing oil & filter every 100 hours or every year, whichever happens earlier. After I cheekily pointed out that it was impossible to know when 100 hours occured, as the LCD display breaks every 50 hours or so, I went on to ask him why the intervals are so short. I pointed out to him that my car (Mercedes Diesel) has on-board diagnostics which determine when oil changes need to be done, and this occurs every 25000km or so, which is equivalent to about three years and 500hours of driving.

His answers were not at all convincing. He claimed that the oil breaks down if older than a year (how comes not in my Mercedes -exactly the same oil?), he then went on to claim that the stresses in my boat engine were higher than in the Mercedes. I pointed out that this was also baloney - my Merc revs to around 6500rpm, continually accerlates and decelerates, and produces 150hp - compared to puny 19hp of my Volvo, which trundles along steadily at about 2200rpm and is never revved beyond 3000rpm. He went off muttering about some important meeting at this point.

cars and boats are different applications and both have very different duty cycles so apart from the fact they both have engines there the similarity ends. The stresses in your boat are similar to those in your car - because they are diesel engines but the boat engine has a much harder life in terms of its oil. Running cold most of the time means it cannot get rid of the water and acid in the same way as the as the car engine; even its crankcase breather breaths salty air! The only way to ensure long life of the bearings is to keep the oil clean - so we change it more frequently in boats. Also engines with turbos are prone to problems if the oil goes to sludge so to keep the turbo happy the oil must be clean. And last - if you car breaks down its no big deal - if your boat engine breaks down the chances are you wont be able to call for the AA in the middle of the north sea. So where engines and boats are concerned change the oil regularly to ensure long life and reliable running.

 

[vyv_cox]

Yanmar recommends 250 hours or one year, whichever comes first, oil & filter change for most of their engines.

But not all of them, and even then there is confusion. My owner's manual for the GM series recommends changing oil every 150 hours. The workshop manual recommends changing oil and filter every 250 hours/1 year as you say, after an initial change after 50 hours.

 

[Marsupial]

But not all of them, and even then there is confusion. My owner's manual for the GM series recommends changing oil every 150 hours. The workshop manual recommends changing oil and filter every 250 hours/1 year as you say, after an initial change after 50 hours.

For what its worth my JH series manual says oil change every 150hrs, filter every 300hr with no difference between turbo and non turbo variants.

Just checked the workshop manual and yes it says 250hrs for oil and filter

However, it seems that those (both) intervals are based on a 1000hr per annum duty cycle . . .

 

[Dockhead]

For what its worth my JH series manual says oil change every 150hrs, filter every 300hr with no difference between turbo and non turbo variants.

Just checked the workshop manual and yes it says 250hrs for oil and filter

However, it seems that those (both) intervals are based on a 1000hr per annum duty cycle . . .

Interesting.

If those oil change intervals really assume 1000 hours a year, then once every 250 hours won't be nearly often enough.

I reckon twice a year must be the minimum. You want clean oil in the engine over the winter. Then you don't want to leave the oil which was sitting over the winter to stay in the engine all year. Ergo, twice, thrice a year, I think.

 

[Chris_Robb]

But not all of them, and even then there is confusion. My owner's manual for the GM series recommends changing oil every 150 hours. The workshop manual recommends changing oil and filter every 250 hours/1 year as you say, after an initial change after 50 hours.

Vyv, I did 4 oil changes this year, on 500 hours. I had installed a water temp and oil pressure gauge - specifically the oil pressure gauge, as it would tell me if diesel was getting into the oil (damaged pump diaphragm). I also presume it would tell you that the viscosity was breaking down when the oil was getting well used.

However, through the season, it always read the same -spot on 65 - even idling hot, when I would have expected it to drop a little. It only takes 10 minutes to change the oil and I only do the filter every other change.

 

[tcm]

Hum, i just wonder how much careful thinking goes into specification of the service intervals and oil levels anyway! Long service intervals might easily be realistic ... but shorter ones are more dealer-friendly!

I note that Yanmar recently sent out a global notification to all dealers that the gearbox oil level dipstick "seems to be wrong" as people who fill t top mark found there seals were blowing.

In any event it just can't be an exact science, a real caluculation, can it? Turn on engine, run it for ten+ days solid and that's 250hours. NOT the same as half an hour or an hour here and there.

I do bout 800hours a year, so quite long running periods, and change oil and filters twice a year. I "flush" the engine - use cheapy oil to clean through the engine, drain and refill. The flush oil is quite filthy so must be doing something to get rid of the nasties.

 

[Marsupial]

Interesting.

If those oil change intervals really assume 1000 hours a year, then once every 250 hours won't be nearly often enough.

I reckon twice a year must be the minimum. You want clean oil in the engine over the winter. Then you don't want to leave the oil which was sitting over the winter to stay in the engine all year. Ergo, twice, thrice a year, I think.

I agree, but dont confuse duty cycle with winterising/laying up, its important to leave the engine with clean dry oil in it over long periods of inactivity, and when you change the oil for winterising run it for a couple of minutes * to get fresh oil into the bearings.

* the time it takes to get antifreeze through the exhaust system!

In general the more the engine is used the less it needs oil changes - but I stress in general; all the caviates about marine use apply.

 

[vertford]

why change the filter...

Interesting stuff, as I am thinking of doing my oil next week. I have a query about the filter change. Not being very mechanical, I thought if I changed the oil and as the engine doesn't run over the winter, no oil goes thru' the filter, so why do you need to change the filter?

Thanks

 

[Marsupial]

for winterising you will need to change the oil filter so you can get clean dry oil to the bearings, if you dont change the filter then you have a litre or so of old contaminated oil in the system - not good.

 

[Marsupial]

Hum, i just wonder how much careful thinking goes into specification of the service intervals and oil levels anyway! Long service intervals might easily be realistic ... but shorter ones are more dealer-friendly!
.

In any event it just can't be an exact science, a real caluculation, can it? Turn on engine, run it for ten+ days solid and that's 250hours. NOT the same as half an hour or an hour here and there.

back in the mists of time I did a lot of work on oil change intervals and the science was to run engines for various periods and with different usage cycles, bakers van, long distance trunker etc, post van, reps car etc. after a specific mileage that varied, dry and weigh the oil filter medium. The result of a years work was extended mileage between oil changes and larger oil filters. However, what went with it was dealer advice to make customers aware that if they only did short journeys they should change the oil and filter more frequently - most customers being cynical ignored the advice and engine failures (worn out pistons mostly) were the result. Its quite possible to get a worn out engine on a vehicle with 20,000 Mile whilst an engine with 200,000 miles has very little wear, all attributable to oil maintenance and how it is used. They were cars and trucks, marine engines are another matter as they GENERALLY have the worst working environment and need more "TLC".