Oil Changes

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Sailfree

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Should you change the engine oil & filter every year?

What if engine has only done say 1hr, say 10hr, say40hr.

At what point would you change it?

Likewise what about Diesel Filters?
 
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Been reading the manual on my MD7a . I've got a lot to learn as this is my first boat with a decent in board engine . Should have got the oil changed at the end of last season so the acid don't eat aay at the engine. Only had her a year so still working out what oil to put in the engine and reverse gear. Then there is the oil filters, fuel filters and annodes, impeller, belt anf probably much more. However iwould much rather learn this stuff than have to buy a new engine. Good luck with yours .
 
Whatever happens I change the oil and filter at the end of the season and before she sits around for the winter. This is received wisdom from the learned community.

Then in the spring change the oil and I change the oil and filter after 100 hours. But this and the pre winter change might both happen in September. All depends.
Buy filters in bulk every couple of years from in-line filters

Hull anodes, usually once a year when the boat is out for the spring scrub. Check the wiring and grounding of the engine circuits.

The impeller gets a look now and again and replace as necessary. Have one of those easy[ ?] replace jobbies. Carry a spare

The belt gets a look and tighten if necessary. Always carry a spare - experience.
 
Nowadays, unlike those far off times when nobody cared very much, almost everything in a car is date lifed, so not just oil but brake fluid, antifreeze, power steering and hydraulics oil, etc. My motorhome doesn't do a lot of miles in some years but the signal comes up telling me it needs to be serviced, which may include changing all of these. I take a measured view on it, ignoring the information if the mileage since the last is very low. It is a long time past any likelihood of a warranty claim, which might alter cases, as it does with my car.

If my boat engine had only done one hour there is no way I would change the oil. A few years ago health issues seriously affected my boating season, engine running for well under 50 hours. I didn't change the oil that year.
 
For those who just run the engine for a few minutes at a stretch, more frequent oil changes are needed because of acid and condensation problems through not being run hot for a while. All manuals for boat engines I've had say 100 hrs but, if it has been run for long periods I'm quite happy to go 20 - 30 hours past that if approaching layup when oil and filters are always changed.
 
Sailfree said:
Likewise what about Diesel Filters?
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Unlike the oil where there's the question of contaminants sitting in the engine (for which I don't have a solid answer), the only thing that determines when a diesel filter needs changing is how much diesel has been through it and how dirty that diesel was. Both of these vary a great deal, so elapsed time is a completely useless basis for changing, and engine hours isn't great either. I've had filters blocked after ten hours' running on dirty fuel, and others still going strong after two seasons. How many hours' running does the filter on your car see?

The best way is to have a vacuum gauge between the filter and the engine, so you can see when it starts to clog and change only when actually needed.

Pete
 
GrahamM376 said:
For those who just run the engine for a few minutes at a stretch, more frequent oil changes are needed because of acid and condensation problems through not being run hot for a while. All manuals for boat engines I've had say 100 hrs but, if it has been run for long periods I'm quite happy to go 20 - 30 hours past that if approaching layup when oil and filters are always changed.
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FYI all my boats for last 16yrs have been on the charter market. On average they did about 300hrs per season (first one was 600hrs with sailing school) and I am sure many of those hrs were near maximum revs. My boats and the other 30 on the fleet always had only one oil change and complete filter change at end of each season. Likewise Volvo state 100hrs on a saildrive leg and boat has to be out of water to drain oil - all just had one oil change at the end of season irrespective of no of hrs!

Current boat has had 10yrs like this but now in my private use only ownership with much less hrs so am considering the sensible approach hence request for others opinions.

I will look up records and find how many hrs I did in 2015 I anticipate about 45!!
 
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The older the engine the more frequent oil changes. The biggest reason for frequent oil changes on older engines (mine is a 40plus year old MD11C volvo) is contamination by fuel passing through and diluting the oil. I do between 40 and 100 hours motoring per season and I change the oil and filter every year; If i do less than say 30 hours, I will not change it; there is no fixed rule in my opinion. Engines that use fresh water for cooling, may have a huge problem with glycol finding its way to the oil and creating acid and increasing the oil viscosity, but, this is a different issue. Oil type and quality is even more important than change frequency. I use modern fully Synthetic oils of low viscosity and high lubrication; which is an anathema for some.
 
I have the engine serviced annually including changing the fuel filters.
But I do about 100 engine hours a year which is the recommended service interval for my engine.
I would expect most people who do less than 50 hours would leave it until the second year. I have no doubt some people would leave it until 100 hours regardless of years.
As time passes I am increasingly of the opinion that lack of use causes more damage than regular use. I am presently dealing with an issue that is under investigation but almost certainly premature wear caused by an oil lubricated part drying out during long idle period under the previous owner . Therefore regular engine use, involving the engine being run for some time under load not just a few minutes , and an annual oil and filter change regardless of hours run should be the best advice.

Fuel filters I would have though should be changed along similar lines and I replace them at engine service. Old fuel that has been sitting around in the tank a few years may be more prone to issues compared to the regular used boat that has refuelled a few times in the year.

Raw water impellers are an item that can be damaged by remaining static in the engine. I had thought mine might last a second year but slight splitting had started so they have been renewed.
 
Too be honest my little 1GM10 uses so little oil it's not worth contemplating it. It's cheap in the grand scheme of things even with a new filter too and only takes half hour so once a year isn't a problem. As mentioned they do tend to just sit around a bit so condensation inside the engine is a problem.
 
TQA said:
Not necessarily the case. It can be highly acidic and not good for the engine over the winter.
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It's an old discussion which I'm sure none of us want to relive ..... but those acids are part of the breakdown process which also produces black carbon plus some smelly by-products. However, I was being somewhat facetious and wouldn't expect people to follow my practice unless they feel really confident.

My best test was a 10 year old mass-production car, 120,000 miles, 4 oil changes in it's lifetime ...... engine/bearings in perfect condition and zero oil consumption between changes. :)

It sold for a staggering amount considering its age, mileage and definitely no FSH.

Richard
 
Sailfree said:
Should you change the engine oil & filter every year?

What if engine has only done say 1hr, say 10hr, say40hr.

At what point would you change it?

Likewise what about Diesel Filters?
Click to expand...


It is a matter of your own judgement in the end. Me, I change the oil and filter every year, I normally do something over 100 hours.

If I did 40 hours I would change the oil but probably not the filter

If I did 20 hours I would not do either

The book says I should change my engine fuel filter every three years. To date it has come out clean, I would happily leave it longer if doing very low hours.
 
RichardS said:
It's an old discussion which I'm sure none of us want to relive ..... but those acids are part of the breakdown process which also produces black carbon plus some smelly by-products. However, I was being somewhat facetious and wouldn't expect people to follow my practice unless they feel really confident.
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People should not imagine that the acids produced are aggressive types that are going to corrode through the sump or some such. In fact the acids are a by-product of combustion and known as 'weak organic acids' such as carbonic, sulphonic and several others. Their worst property is that they corrode lead, which is present as a protective overlay on the surface of most bearing types, and an inherent component of copper-lead bearings, which are fitted to the majority of engines used for yacht auxiliaries. I suspect that they would be unlikely to do a great deal of damage if left cold in the engine over winter but substituting new oil that contains no combustion products will always be better.
 
vyv_cox said:
People should not imagine that the acids produced are aggressive types that are going to corrode through the sump or some such. In fact the acids are a by-product of combustion and known as 'weak organic acids' such as carbonic, sulphonic and several others. Their worst property is that they corrode lead, which is present as a protective overlay on the surface of most bearing types, and an inherent component of copper-lead bearings, which are fitted to the majority of engines used for yacht auxiliaries. I suspect that they would be unlikely to do a great deal of damage if left cold in the engine over winter but substituting new oil that contains no combustion products will always be better.
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And for those reasons, it is important to give the engine a run after the oil change, so that it is fresh oil in contact with bearings etc.
 
Always change the oil and filters once a year which will cost you less than £50. A replacement engine will cost you several £ thousand.
The worst thing you can do to a diesel engine is not use it, the second worse thing is to run it on light load for short periods.
Change fuel filters annually. There is no direct correlation between use and risk of contaminants. In fact a little or no use can be more likely to encourage diesel bug growth.
Do all the above to minimise the chance of breakdown at sea.
 
CAPTAIN FANTASTIC said:
The older the engine the more frequent oil changes. The biggest reason for frequent oil changes on older engines (mine is a 40plus year old MD11C volvo) is contamination by fuel passing through and diluting the oil. I do between 40 and 100 hours motoring per season and I change the oil and filter every year; If i do less than say 30 hours, I will not change it; there is no fixed rule in my opinion. Engines that use fresh water for cooling, may have a huge problem with glycol finding its way to the oil and creating acid and increasing the oil viscosity, but, this is a different issue. Oil type and quality is even more important than change frequency. I use modern fully Synthetic oils of low viscosity and high lubrication; which is an anathema for some.
Click to expand...
Interesting - Yanmar state that under no circumstances should synthetic oils be used as these can seriously damage the engine.
Only mineral oils should be used in non turbocharged engines.
 
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