BEST TIME TO SERVICE DIESEL

alisdair4

alisdair4

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Isle of Bute
midnightdrifter.net
Normally, I service our engine at the end of the season. This means that dirty oil (sulphur - rich?) doesn't sit in the sump when the engine is not being run for 5-6 months.

Normally, we run the engine (Beta 34 HP) about 100 -150 hours per season. In 2022, we managed only about 20 hours of engine. (Work is the curse of the sailing man, to paraphrase Oscar Wilde......)

This winter we are leaving the boat in the water. Thus, I will probably run the engine up to operating temperature at least once per month (maybe every fortnight) between now and early April.

Is it therefore more logical to change the oil and do the other service-related stuff in the spring?
 
Your engine is not going to be damaged if you do nothing until next winter, or even the one after that, so leaving until spring is irrelevant, but as the old adage goes, don't put off until tomorrow what can be done today. On the upside, if you break something on the engine servicing it now, you have all winter to fix it.
 
Biggles Wader said:
Why will you be running the engine every month or two weeks? Cold starts probably cause more wear than several hours of normal use so are best avoided unless the engine is actually required for "work"
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Perhaps to use the boat for winter sailing?
Modern cars go two years before oil changes, perhaps 25,000 miles or more. The oil at 20 hours is almost new.
 
Well, you are all certainly changing some assumptions! My reason for running up the engine has been to make sure that "all is well" when I visit (really, just a comfort blanket)? If it is doing more harm than good, then I will desist!
 
"BEST TIME TO SERVICE DIESEL"

I used to do an oil change when ashore over the winter, it was always a pain.

My new technique is to change the oil at the end of a trip out, when the engine is properly hot., anytime towards the end of the season. The next day I change the filter with the engine cold - much less mess. I ignore the few hours I put on the engine before hoisting out.
On the day the boat comes out, I run a bucket of soluble oil + anti freeze into the warm engine and that's it until the spring. Same principle could be ok if you are laying up the boat afloat, saves cold starts and mucking about when you are busy with other things, often in chilli weather.
 
alisdair4 said:
Well, you are all certainly changing some assumptions! My reason for running up the engine has been to make sure that "all is well" when I visit (really, just a comfort blanket)? If it is doing more harm than good, then I will desist!
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Very sensible to run the engine regularly if you can BUT it must be under load, that is in gear at between 1500-2000rpm for about 15-20 minutes. This will get it up to operating temperature and put a few amps into the batteries.
 
Tranona said:
Very sensible to run the engine regularly if you can BUT it must be under load, that is in gear at between 1500-2000rpm for about 15-20 minutes. This will get it up to operating temperature and put a few amps into the batteries.
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If doing this, take a little trip out. There are a few that do it tied up in our marina, which is dangerous as it creates several knots of current across the fairway and can cause chaos if other boats don’t spot it, and let’s be honest there’s no reason you’d be looking out for it.
 
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lustyd said:
There are a few that do it tied up in our marina, which is dangerous as it creates several knots of current across the fareway and can cause chaos if other boats don’t spot it, and let’s be honest there’s no reason you’d be looking out for it.
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On our tidal linear pontoon moorings this is common practice, any prop wash can affect the boat immediately astern ( 2 metre spacing ) a little but never noticed any effects beyond that and this could be a pair of 200- 300HP engines @ 1000-1500 rpm
Exhaust noise on a quiet day can be heard over the entire moorimgs.
Perhaps MoBo are less affected due to their shallow draught.
 
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alisdair4 said:
Well, you are all certainly changing some assumptions! My reason for running up the engine has been to make sure that "all is well" when I visit (really, just a comfort blanket)? If it is doing more harm than good, then I will desist!
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There is absolutely no point in running the engine over winter for no purpose other than reassurance. As pointed out, most wear occurs in the few seconds after starting and even more so after a month, when oil has had a good time to drain from rings and bores. Low temperatures make the situation worse, as oil will be more reluctant to pass through small oilways.
I have no such options, as my boat is left in Greece for six months. I carry out full winterisation , change oil and filter, drain down. It never fails to start on my return (even after a 3 year break), usually within a couple of seconds. This has been the case for 20 years.
 
oldgit said:
On our tidal linear pontoon moorings this is common practice, any prop wash can affect the boat immediately astern ( 2 metre spacing ) a little but never noticed any effects beyond that and this could be a pair of 200- 300HP engines @ 1000-1500 rpm
Exhaust noise on a quiet day can be heard over the entire moorimgs.
Perhaps MoBo are less affected due to their shallow draught.
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In that scenario it might be OK. In standard marina layouts there will likely be a fairway behind you that other boats will be moving along to get in and out. Suddenly finding a 4kt cross current you weren't expecting will push you hard into the boats on the other side of the fairway.
 
lustyd said:
In that scenario it might be OK. In standard marina layouts there will likely be a fairway behind you that other boats will be moving along to get in and out. Suddenly finding a 4kt cross current you weren't expecting will push you hard into the boats on the other side of the fairway.
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In the middle of winter will there really be lots of movement down the fairway? Whatever happened to commonsense? Don't do it if that is the case (although I think your image of the effect is a bit over dramatic).

Running the engine under load in a marina berth is no different from going out for a short run. The key thing is to get up to operating temperature. The "wear" bit from cold starts is way overstated. Just think of all the cold starts happening just now in the UK. Or more directly relevant all the little Kubotas in diggers etc on building sites that will sit unused over the holidays exposed to all weathers and still manage 8000+ hours before they wear out. 3 or 4 cold starts on your boat engine in the winter will do absolutely no harm to the life of the engine.
 
Tranona said:
Whatever happened to commonsense?
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I agree, it's completely missing as I see this happen quite a lot, including through summer.

My image of the effect is a description of the outcome I've seen on several occasions. I didn't imagine it, I saw it play out.
 
Tranona said:
Running the engine under load in a marina berth is no different from going out for a short run. The key thing is to get up to operating temperature. The "wear" bit from cold starts is way overstated. Just think of all the cold starts happening just now in the UK. Or more directly relevant all the little Kubotas in diggers etc on building sites that will sit unused over the holidays exposed to all weathers and still manage 8000+ hours before they wear out. 3 or 4 cold starts on your boat engine in the winter will do absolutely no harm to the life of the engine.
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But it is totally pointless. Running an engine in the berth monthly achieves absolutely nothing that starting it first time in April does not. When industrial engines start during a cold spell at least there is some purpose to it.
 
Apologies for the drift, but is there a way you could squirt extra diesel into the cylinders before starting up ?

It might help with lubrication.

My Volvo 2001 used to do this as a starting aid.
 
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