How often do you really need to service engines?

[Nick_H]

I had a full change everything service on the engines, gearboxes and genny a year ago when I bough the boat. Have done about 100 hrs since. The manuals have at least a 200 hr change interval on everything except the engine oil, which is 200 hrs or 1 year, whichever comes sooner. However when I bought the boat it had done over 100 hrs and 12 months since its previous service, but when I had the oil analysed, they said it was OK for continued service.

Does the oil really need changing just cos its a year old, even modern high quality synthetic oils? Can't see what else would be done if I have the engines serviced, so am tempted not to bother. The boat has stayed in the water all winter and is running perefectly.

 

[DavidJ]

I believe there is a direct correlation between engine wear and oil change frequency. As an example a pal of mine with a Saab changes his oil at twice the recommended frequency from new and has done over 300.000 miles. (the rest of the car is a total knacker but the engine's fine)
So you will not notice the difference in running, I'm sure, if you left it a couple of years but you are adding to the overall wear and reduced longivity of the engine
David (also from Birmingham and with a Sealine)

 

[omega2]

I would change the oil and oil filters once a year at least, or 200 hours. fuel filters and pre filters are a tricky proposition generally we do ours when the revs drop off mind you we are running ford Dorsets and they are very forgiving if not as evironmentally friendly as modern engines

 

[GrahamR]

I agree with DavidJ ,oil changes more frequently do tend to lead to less problems,bit of a bind but cheaper than a new engine.

 

[hlb]

I think I'd be tempted to service each year, but use normal oil as you dont realy need a synthetic that will do umpteen hours. Worth servicing though as faults often pop up.

 

[Marsupial]

I agree with HLB, about what oil to use, and IMHO you should change it as frequently as possible, I do mine every 50 hours - why?

1. Boats are not used much compared to cars.

2. Boat engines are usually run at full power, or spend a lot of time at idle.

3. Boat engines often run cold.

4. Most boat engines are diesels so they make lots of carbon.

All these things are not "good" for engines and oil. Oil degrades rapidly when its forced through fine gaps (bearings) so it looses its lubrication properties and condensation and soot is no help at all, it soaks up lots of moisture and acids and it can become very corrosive. The best thing is to replace the oil regularly.

Engines live longer with fresh clean oil in them.

Cheers


David

 

[DAKA]

There used to be a boat kept a short walk from mine owned by "Old Harry" I don't know how old he was but he knew everthing about boats.
He had an old converted lifeboat with a single cylinder diesel, he used to change his oil every year without fail, I asked him what he used one year " Colin's" he replied.
I later learned that Colin chaged his oil every year and didn't cover many miles in a season so looked after the 'part used' oil for Old Harry to re use.
I don't recomend you use second hand or cheap oil but you could think of recycling.

 

[Chris_d]

I'd second that,, er third that.. then, I change all mine, engine, outdrive every year regardless, its not the quality of the oil thats the problem its all the stuff that gets into it you have to get rid of. As already said boats don't run as hot as cars and are left unused for long periods, so any contaminates corode the engine from the inside out, also the best time to change the oil is at the end of the season, not before the start, that way any acids, water etc.. left in the oil is not sitting there all winter doing their worse.

 

[Dave_Snelson]

At the end of every season. It gets rid of any acids on winter storage. Oddly enough though, with my motors running LPG, the old oil comes out the same colour it went in. Just shows what carbon and soot is manufactured during combustion of more traditional fuels. Ditto drive leg oils and fuel filters (for petrol cos its duel fuel).

 

[Medskipper]

Iv'e been boating fifteen years and been maintaining my own car engines 40 years!

Always change your oil every year with a good quality oil! it you have a diesel engines which is under ten years of age you may find that you should only use synthetic oil, check the manual as it will not do the engine much good if you use a cheap mineral oil. By the same token if your engines are old, then don't use Synthetic oil as it may damage the engine, again consult your manual. Always use the correct recommended oils and do not consider using a cheap alternative, I can assure you that you will get a longer life from your engines. I would also add that the engine oil should be changed straight away if you get a blocked intake and the engines overheat! this is because the viscosity of the oil is comprimised by an overheated engine.

Gearbox oils do not have to be changed every years, but its always good for the box to have fresh oil! oils are cheap so there is not excuse really. Think of it this way, how much did you pay for the vessel? and do you want it to give you a good return when you sell it?

Regards

Barry

 

[jfm]

I agree the thought you have houghn, that changing the oil in those circumstances is pretty unnecessary.

On the point that more frequent oil changes means longer life, yes that's true. But it's a matter of balance. If you go by that principle you would change the oil after every trip. What you need to find is the point where the £££ saved by not changing the oil is offset by the £££ cost of wearing the engine too much, and that point is surely more like 200 hours than 100. On our D12s the recommended hour frequency is 400hrs

On the issue of nasties left in the oil to fester over winter, yes that's true too but I'd guess that one season's worth of nasties wil have negligible effect. The engine innards are made of heavy thick metal

After 100hours there could be other service needs like filters, electronic diagnostics, etc

On Mirabella V they have oil cleaners on the MTU main engines and the gensets. These scrub and filter the oil then put it back in the engine. The oil is therefore not changed for 1000hrs plus, all that is changed is a fine filter in the oil cleaner unit. The same kit is installed by various truck/bus firms in USA with oil changes at 50,000 miles and excellent results in terms of engine wear. Forgotten the brand name of this kit, will try to remeber it

 

[muchy_]

I change my oil twice a season.
Oil=cheap.
New engine=F*** me, get away, you cant be serious. Holly sh*t. Oh my God. What the....Why the......How the....... : /forums/images/graemlins/frown.gif

 

[gcwhite]

Oil change is important. Time as well as use is a factor here. Also check the warrenty

/forums/images/graemlins/grin.gif

 

[Nick_H]

Thanks to all for your advice. On balance I'll change the oil on the basis that, as a few people pointed out, its fairly cheap to do so why not?

 

[Chris_d]

The other thing of course is resale, if given the choice between 2 identical used boats, I would buy the one that has been serviced every year, not the one from the guy who has stretched the intervals to the max to save money, make sure you keep the receipts and you'll win in the long run.

 

[JoeV]

The bypass filter unit is made by Puradyn Filter Technologies . It is fitted on all the Mirabella's. You know the old Ronson ad..."I liked the product so much, I bought the company"...same deal here, Mirabella's owner (my father) is the Chairman, and second largest shareholder (I think). The biggest shareholder is George Soros (yes that one). Anyway, obviously we think the product is brilliant, but like the everlasting lightbulb, the rest of the engineering world is skeptical. Engineers have been raised on oil-change schedules, and being told that you either don't need to anymore, or can extend it by ten times, seems to be impossible for them to comprehend.

So the company has a very challenging task ahead. Obviously I think they're onto a winner, but one glance at the share price over the past three years will suggest that I am in the minority. Anyway, if anyone's interested here's some independant analysis. Also I think they are standard on Aggreko generators, so they have a reasonable presence in the UK.

OK, that's the end of the infommercial. Sorry about that JFM!

 

[srm]

I know of commercial fishing vessels that use oil cleaning devices, but these are backed up by weekly oil samples sent to a lab for analysis.

 

[JoeV]

Puradyn requires that an oil sample be taken when you change its cotton filter. You do this INSTEAD of an oil change, and can be done with the engine running. This goes off to a lab which confirms the oil is still clean. The service does not cost much. You do not need to do it weekly, unless that's your normal oil change interval. Puradyn really works best for people who want to keep the engine running, and for whom oil change is a hassle. Boats are a great example, since carrying the oil around with you (especially the dirty stuff) is bothersome and inefficient.

 

[Its_Only_Money]

Oil also loses its viscosity with use though - a chemist told me that it starts with long-chain molecules and they get chopped up into shorter chains with use (personally I failed Chemistry at school). I do notice however that when I change my cars oil it is noticably thinner than the new stuff (same spec), going in. So good oil IMHO isn't just clean it has a service life too. Not sure how any filtration will overcome that aspect so it would seem to be an overriding limit wouldn't it?

Anybody got a more qualified view on the physical chemistry changes going on?

 

[Chris_d]

Don't know the science, but modern fully synthetic oils are virtualy indestructable good to 1200degC+, company I work for used to use Mobil 1 in formula 1 engines, its was changed obviously very frequently and sent back to Mobil who just filtered it and sent it back. Basicaly the only reason to change a fully synthetic oil is to get rid of the crud its picked up on its way round, mineral oils are a different ball game though and do actualy break down over time as does anything organic.