Run engines over winter or not

Momac

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My boat is in the water but hasn't been anywhere since late October and may well not travel far for some months.
There may be an occasional winter opportunity for a trip out.
I am reluctant to run engines (diesels) while going nowhere a I feel this does more harm than good .

What do most people do. Run the engines at the mooring from time to time or leave them alone until needed for propulsion?
 
I leave mine, the boat is in the water all year round, but doesnt get used from November to May, the engine wont get run over that time.
 
Haven't done it yet as we have been out of the country but usually run the engines in opposition for 20 mins every time we go and check on the boat
 
I run mine up and leave at just above idle in forward and quick blast in reverse before powering off. Engine will not reach any more than 70C so soon as it hits 70 I power off. I like the idea everything gets a coat of oil. The volvo manual recommends doing this every two weeks if boat not used.
 
I run mine up and leave at just above idle in forward and quick blast in reverse before powering off. Engine will not reach any more than 70C so soon as it hits 70 I power off. I like the idea everything gets a coat of oil. The volvo manual recommends doing this every two weeks if boat not used.

What he said.

I have a cruiser style motorbike which has little chance for a road run at this time of year. Thus, at least every week, the engine is fired up and allowed to run for 15-20 minutes: it turns the oil and moves some petrol around. I wouldn't dream of allowing it to sit all winter with it being warmed over.
 
I will run engines now and again over winter but only if they are able to reach normal temp for at least 10 a 15 mins , ie out for a run , so that oil gets hot enough to evaporate any moisture .
 
I take the boat out every six weeks or so throughout the winter - warm up pottering out for 15 mins, 15 mins at 1000rpm and 30 mins at 1800rpm - if I can't get down to the boat to take her out myself I get a prof skipper to do it. Personally I don't like to leave the engines unused for five months as I worry about the internals drying out and possibly corroding etc. Might well be an unnecessary concern - would be very interested to know what the pros think (Latestarter etc)...
 
I agree with andy59. Unless your engines are run up to full operating temperature you are doing more harm than good.

One of the dangers comes, I believe, from condensation in the cooler parts of the engine if it is not fully warmed up.

The cooler parts include the valve springs. Condensation on them can lead to surface corrosion, stress cracking and failure.
An engine in which a valve spring has broken and allowed the valve to drop is not a pretty sight.
 
One of the dangers comes, I believe, from condensation in the cooler parts of the engine if it is not fully warmed up.

The cooler parts include the valve springs. Condensation on them can lead to surface corrosion, stress cracking and failure.
An engine in which a valve spring has broken and allowed the valve to drop is not a pretty sight.

We could do with an expert commenting. I'd worry more that four months without operation would leave no oil film left on parts to protect them. I presume that atmospheric pressure fluctuations will effectively force air in through air filter / turbo to equalise pressure so damp air will be forced and sucked out all the time, depending what the weather's doing. This damp air will presumably form condensation inside the engine if conditions are right?

Over to an expert to confirm whether running engine every few weeks will help maintain oil film barrier against said condensation?
 
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18 months ago I had a serious engine problem on my boat. It failed in October and wasn't run again until the following May - nearly 7 months. We started taking the engine to bits at the end of April, cam cover off, timing gears out oil sump off etc etc. Everything - everything was covered in oil. We also removed the inlet manifold - all bright and shiny inside the cylinder head ports and we used a mini camera to look into valves etc. Everything bright and shiny. If you are still worried - take your rocker/cam cover off in the spring and have a look at the still oily bits before you start the engine after the winter.

Castrol and Co are in business to sell us more lubrication oil. If we need winter oil what's wrong with the regular stuff they sell us? (Answer: nothing it's really good and full of protective chemistry already)
There are a lot of myths with boats - leaving an engine alone for months with oil in it and I believe it will be fine. Running it for ten minutes and then leaving will re-circulate the oil but suck in fresh damp air and incomplete combustion will produce acids that will then possibly fester (assuming you engine oil can't deal with it anyway).

I think you are better either 1) take the boat for a proper run with load on it or 2) winterise the cooling system and leave it alone. I am in the process of reviving an old car. Recently I had the oil sump off, oil pump out, big ends off and various other bits and it was like new inside. It had been stood for ten years.

I don't fill my tanks with diesel at the start of the winter either - yes you may get condensation, but I worry more about the quality of fuel bought and seals on the filler caps.
 
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Running off load will glaze the bores, if you must, turn it over put the run/stop lever in no run run mode turn over until you see the oil pressure gauge flicker and that will be that. In fact Sabre/Mermaid/Lehman advise this at every start up. If you are not going to run it up to temp then do not start it.
 
Mechanical things like engines are meant to be used, sitting around for months on end IMHO does them no good. I've been boating 30 years and always run my engines up throughout the winter in gear on the ropes until a decent temperature is reached, approx half an hour or so. I have to say that I've never had to strip down an engine or had engine problems and my boats have always been twenty or so years of age.
i would be interested to hear what mechanics and someone like Volvo Paul thinks though?
 
I always run ours at least once every two months. I also subscribe to the notion that mechanical things like engines should be used. Yes, it's true that you can glaze bores, but not really with a few minutes of running. It gives me peace of mind, and I also know that it's still in usuable order rather than finding it in a non-working state in the Spring.

That said, my FIL has a sail boat in the garden - the Yanmar engine in it hadn't been started for about 8 years, and the boat had filled with rain water several times. With a decent battery we got it going in no time - I was expecting it to be siezed solid!
 
Interesting thread.

For me the most important thing is the cleanliness of the oil over the winter period.

The last thing I do at the end of the season is change the engine oil & filter, so that the engines are sitting with fresh oil over the damp, cold months of inactivity.
Personally I don't normally start them up again until the spring, for the reasons stated above that if you can't get the engine up to full operating temperature (including the oil, not just the coolant) then it's doing more harm than good.
It probably wouldn't matter if I did start them up because the additives in the fresh oil would more than cope with a few luke warm runs, but I just feel it is best left alone and as stated in another post above, in reality the oil film remains on the surfaces quite adequately for the whole winter without needing to be started or turned over regularly.

The one thing I wouldn't recommend is changing the oil at the start of the season instead of at the end, because it means leaving used oil against all the bearing surfaces over the winter, with all those potentially acidic deposits from a season's use. Yes, that's what all the additives are for in the oil but it just isn't good practice, and seems to me to be tempting fate (or at least pushing one's luck).
 
Same here. Autumn service, winterise, and leave well alone till the spring.

I've always been advised that getting an engine (particularly a turbo diesel) only partially up to temperature (and you'll never get a turbo diesel up to normal temperature without running it normally - ie cruising speed/revs/load) and then shutting it down is inadvisable.
 
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