How often do you need to start a diesel engine?

I'll be gone for six months. Will it be OK if my diesel engine is not started in that time?

Sure, Great Lakes boats are winterized and laid up for 6 months every yr.

If you are leaving your boat in the water, in Seattle, it is unlikely that you will see temperatures of below freezing, especially if you have a charger/inverter left on, a water heater left on or some other small source of heat in your ER. If none of those conditions exist, you should put a small electric heater down near the engine(s).

My experience with abandoning a diesel for the winter dates from when I retired, after which, we have become snowbirds. My boat is left totally on her own for almost 6 months every year and has shown no ill effects after 4 repeats, with another few planned, US politics willing.

I lay up my charter boat up for 6+ months every year in Maryland. Would recommend changing the engine oil, transmission oil and coolant (if it's been a few years) before lay up.

Ted

O C Diver said:

I lay up my charter boat up for 6+ months every year in Maryland. Would recommend changing the engine oil, transmission oil and coolant (if it's been a few years) before lay up.

Ted

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Agreed. Make sure you change oil *before* layup. You might also have the marina start them once a month in the slip. 15-20 minutes with one in forward and one in reverse might be good.

PAL, we leave our boat in the water all winter. To winterize it I drain the fresh water systems and blow out the lines. I put a 1500W heater in all 3 staterooms, both heads, the salon and galley. They're set to the 750W setting and the thermostat set low.


I use a Boatsafe 1000W heater in the engine room and that keeps the Cats above the freezing temp.


Don't forget to close your seacocks and when blowing out lines don't forget your anchor wash down and stern shower if you have one.

It rarely gets cold enough in Seattle to worry about it much, but when it does one small heater in the boat is usually enough. I remember my uncle would go down and start up all his tugs in Fremont late and run them for a while so they were warm for overnight, he didn't like heaters due to fire hazard. I keep one heater on low in the boat when it gets cold.

Layup is no problem,, IF "Da Book", the engine mfg maint manual is followed.

Some require far more than others , including perhaps special oil in the injection system or sealing intake and exhaust..

Operating a laid up engine before the next operating season defeats the process.

I've done it many a winter. Winterize if needed, add fuel stabilizer and top off the tanks (diesel). Run engine(s) long enough to get the stabilizer in the entire system. Yes, change oil BEFORE layup. Run a few more minutes and viola. If you're really OCD you can shut off the seawater through hull and feed some fresh water with corrosion inhibitor into the strainer.

My boat has been laid up for 6 -7 months a year for 44 years. No problems with the engine yet, but we will see what this winter produces.

running for 20 minutes at idle is not recommended.

Doing the annual oil change before layup is probably a good idea. I dont add any chemicals to the fuel. Never have never gonna.

OTOH The results will probably be the same if you just turn them off.

Short term running is bad, hard on the engine, since the idea is they don't get hot enough to drive off water which corrodes things. IMO, it is cylinder rusting that is the worst thing from sitting real long times. But that could be a year or more. If a valve is open, then the cylinder is exposed to humid air, and water does condense out of the air. I have taken heads off engines sat for years, some cylinders will be rusted, and others fine.

And before anyone thinks "OK I'll just crank my engine w the starter motor to re-lube the bearings".
If you have a lift muffler it will fill up and possibly REALLY ruin the engine.

bayview wrote;
"running for 20 minutes at idle is not recommended."
I've heard that forever but not convinced that it's true. Now and then I think it will do more good than harm. But all winter long is almost certainly bad.
Rules applied to the letter are often not good.

Short runs not optimal, true. But on diesels, there is very little water created from combustion so it does not put much moisture in the oil.

Rusting of cylinders and valves is a bigger deal than putting moisture in oil, so given a choice I would do a five minute run once a month or so. No need to heat up coolant to temp, that takes forever with no load, and oil will never get hot enough to cook out moisture.

When possible, go for a run and load it up good for an hour to dry out the oil.

A little bit of block heat does wonders for minimizing corrosion both inside and out, but not always possible.

Detroit two strokes are particularly prone to cyl corrosion due to ports and valves being open at same time. Breeze literally blows right through. DD guys need a good strategy more than us four stroke guys.

While a short run at 1,200 rpm won't cook the moisture out, you are moving oil all around the engine, cylinders get a fresh coating, piston rings get flexed, and the moving parts are most likely in a different position when turned off.

My charter boat will be on the hard for 18 months while I do the loop. The above is my plan every 6 months. Will hook a fresh water hose to the raw water for cooling and water pump lubrication. Will have to winterize the raw water side again for next winter, but that's just a few gallons of RV pink stuff.

Ted

Brian Smith recently told me that laying up naturally aspirated Ford Lehmans for a couple of years at a time is no problem if you change the oil beforehand, drain the raw water and ensure adequate anti-freeze protection. He also said fogging was unnecessary unless the boat's stored in high humidity.

"DD guys need a good strategy more than us four stroke guys."

The DD is really easy , the air box covers , 1 bolt in eachare easily removed.

A spray of storing fluid , a tiny roll over and spray again will coat cylinders pistons and rings. Seal intake and exhaust .

Only expense is for air box gaskets , if its been decades since last serviced
6-71 about 15 min and $20 , if you need the gaskets.

Much harder is the requirement for special storage oil for the injectors.

Which is hard to find.

Since the boat will be sitting in water that is above freezing you don't need to worry too much about the cold. I use one or two of these in my boat over the winter. It helps keep the boat just warm enough to keep moisture down.


You don't want to use a typical electric heater such as the one below in the boat while unattended. Even on low, if the fan motor should seize up the heater could overheat and pose a fire hazard.


I have considered using an oil pan heater on the boat. It would keep the engine oil warm for an easier start as well as keep the engine and therefore the ER just warm enough to avoid some moisture problems.

I would think that an engine could sit for the off season without damage and it's commonly done in the northern part of the country where boats sit on land for six months or more without the engine being run.


A well respected diesel mechanic who used to work around my marina disagrees. He pointed out that one or more exhaust valves would be open to the atmosphere and moisture could get into one or more cylinders and cause rust. Running the engine periodically would alternate which cylinders are open to this possible condition. I suppose plugging the exhaust would take care of the problem.


So- I really don't know the correct answer.

On the hard in NE over winter usually has low humidity, that helps. Better yet in a shed. Leave an engine on the hard in nc, much worse. Wild temp and humidity swings with fronts routinely cause condensation.

WesK said:

A well respected diesel mechanic who used to work around my marina disagrees. He pointed out that one or more exhaust valves would be open to the atmosphere and moisture could get into one or more cylinders and cause rust. Running the engine periodically would alternate which cylinders are open to this possible condition. I suppose plugging the exhaust would take care of the problem. . . . . .

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I didn't used to think that either, but learned the hard way when I was out of country for 6 months. Upon returning and starting port engine, exhaust valve was stuck closed and it bent a pushrod. Removed rocker shaft and tapped the end of the valve stem with a hammer a couple times and it popped open. Replaced the push rod and all was well.

Since that experience, I try to start the engines at least monthly or at a minimum roll them over with the starter for a few seconds every visit to the boat. If I go away that long again I will disconnect and plug the exhaust. If you do that, be sure and tag the throttles so no one tries to start the engines.

John Deere says I should operate its engine at least once a week. Nevertheless, it averages twice a month, year-round, with occasional three and four-week intervals (totaling about 100 hours a year). Run it at least three hours at a time, under load, while boating. (None of this running in neutral at berth.) Still, the engine starts right up and runs well, and it will undoubtedly outlast me.

Wifey B: At least two or three times a week. Maybe every day. I can't go long without starting one

Oh you didn't mean how often do I need it but you meant "How often does a diesel engine need to be started?"