engine warm up

hi all
we are in freezing temperatures right now
debate as to warming engine at dock
lehman 120 diesel
have heard recommendation to just turn her on for 30 seconds to get oil up into engine I am not so convinced
any thoughts
thanks and happy new year
keith

Edit to reflect understanding that this is a dock situation:

If you just idle at the dock to warm the engine up it may take forever at low ambient temps. And all the while you are sending unburned fuel out the exhaust and probably adding carbon to the valves, rings and exhaust manifold.

But, I believe it is not necessary to start your engine in the winter. Tens of thousands sit on the hard each winter and never start.

If you want to do it and there are some possible benefits- driving condensate from the oil, turning over the engine and putting a new oil film on the bearings, then warm it up completely at the dock with the boat tied down tight and a little load on it. It will take a fraction of the time as at idle.

I just took my grandkids snow sledding to a hill a mile or so away from our house. When we got there the heater hadn't kicked on so I let it idle for 20-30 minutes hoping to warm me up but it never came on. Within a minute of putting it in gear to go home it kicked on. Same thing.

David

Keithmilton said:

hi all
we are in freezing temperatures right now
debate as to warming engine at dock
lehman 120 diesel
have heard recommendation to just turn her on for 30 seconds to get oil up into engine I am not so convinced
any thoughts
thanks and happy new year
keith

Click to expand...

Many threads in the past have dealt with this issue. A search will turn up some surprises.
Many think getting the oil up is beneficial. Many others believe that the harm done to your engine by that cold scraping of piston rings against dry cylinders is worse than any possible benefit, and can only be mitigated by a period of hard running that allows the oil to reach full hot operating temperature for long enough to evaporate out any moisture.

I have always tried to run my engines to full hot if I ever have to start them in the winter. My protocol now that I winter far from my boat is to start them only when I return in 5 months and not worry about it in the interim. So far that is working well for me.

Of course your situation will be different.

Don't try to warm them without a load. Let them sit until spring.

I am with change change engine position and coat with fresh oil at least once a month.

If you can run long enough under load to hot oil, better, but usually not practical.

If you cant deep store to manufacturer specs a turn over, without start to full oil pressure isnt bad either.

I am in the "leave it alone" camp.
However, in reality I don't believe it makes much difference.

Lots written here and at boatdiesel.com on this topic. I'm of the opinion that if the boat stays in its slip for the winter, leave the engines cold and don't start them till spring.

depending on how long your winter is....

and whether you "winterize" that includes fogging cylinders or equivalent....

the one time I didnt turn over my engine every month, the iron in my oil samples went way up .... possibly signifying rust in the cylinders.

This old chestnut is as bad as discussing anchors or stern thrusters. If you can’t be bothered to read the reams of blather about this topic in the search function, go have a nice rum or go for a walk until the urge to write some anecdotal nonsense about your defining moments in boating goes away. Happy New Year!

Ours sit from October til at least March. No problems yet.

Xsbank said:

This old chestnut is as bad as discussing anchors or stern thrusters. If you can’t be bothered to read the reams of blather about this topic in the search function, go have a nice rum or go for a walk until the urge to write some anecdotal nonsense about your defining moments in boating goes away. Happy New Year!

Click to expand...

warm welcome.

The problem is, while this has been discussed quite a bit, the Search feature isn't quite as awesome as we'd like to think.

I just searched "engine warm up", "warm up" and "idle". I didn't manage to catch any discussions which appeared to be related. Maybe the titles were misleading. It's easy to criticize someone. Can you easily provide links of similar discussions? Improved search criteria to return hits within the scope of the query?

Most engine wear occurs at startup. Very cold oil doesn't lube well unless it's a blend usually including 5w oil. Using a block or pan heater before starting helps.
In cold weather my pickup, using high pressure motor oil activated injectors, won't run right until idling for about 10 minutes unless the block heater is used.
Starting a cold engine several times over winter probably causes more wear than a seasons use.

My Mitsubishi S4L2 warms up to 180 degrees f. In less that 5 minutes.
That’s just the coolant but it sends heat throught the engine w the exception of the crankshaft.
I’m not in the run straight away camp. I think as long as you run for an hour or so at 50% load or more idling for 5 or so minutes prior won’t hurt anything. Many disagree w that but it’s kinda like straight 30W or 15W40. Either is just fine.

With a bigger engine that won’t pop open the thermostat open at an idle I’d warm up at 12-1400rpm under load. As said above.

And often overlooked is the warmup AFTER the 0-5 min start. I leave the dock/float at 1400 that would equate to 1200rpm on a bigger engine and I run for 20 to 30 minutes like that. Then 1800 for 10 -15 min and only then go to cruise of 2300rpm. So at times I spend a bit over 45 minutes getting to cruise rpm/load. That may be overkill but I think it’s good. But it wouldn’t be overkill for a bigger engine. My Mitsu is rated at 37hp.

People that sell engines including manufacturers probably find it a better/safer bet to tell customers to set out immediately that to make it more complicated and having customers idling for long periods (15 min) or more. It’s natural for the human mind to slip into the “if somes good mores better” groove.

Shrew said:

................ The problem is, while this has been discussed quite a bit, the Search feature isn't quite as awesome as we'd like to think. .........

Click to expand...

The real problem is, half the people say to run it and half say not to. By the time you get done searching and reading, you won't know any more than you know now.

I'm fine without running the engine for 7 months. Have been doing it for 15+ years on my charter boat with no ill effects. Oil analysis seems to confirm this. All 3 of my diesel propulsion engines have block heaters. So frigid winter starts would be no problem with a 3 hour preheat.

Ted

aboatman said:

The real problem is, half the people say to run it and half say not to. By the time you get done searching and reading, you won't know any more than you know now.

Click to expand...

boatman,
Where are you?
West coast or east?
Washington .... state or DC?
They really should ask what state or province IMO.


Ted,
Do you ever fog?

Nomad Willy said:

Ted,
Do you ever fog?

Click to expand...

No.

Ted

Let sleeping dogs lay. No need to poke it during hibernation unless needed.

I am totally lost - what are you guys talking about?

I keep mine at rest for month in our harsh winter. In spring it started like I never stopped it. Hopefully will stay the same for next 30 years

L

I only start my Cats if we're heading out. I start them when I get to the boat and usually we're out of the slip within 7-10 minutes.


Other than that they will sit for months and fire right up within a few seconds when I do crank them up.

My engine builder (JD) says not to idle the engine without load for more than five minutes. We time to leave the berth within five minutes of engine starting, and run at high idle speed (1100 to 1400 RPM) leaving for 15 minutes before reaching cruising speed (1800 RPM). Maximum speed is reached at 2200.

Umm, if you're not leaving the berth, best not to start engine{s} unless the dock's cleats can hold while the engine is engaged with the propeller so there is a load. If not reaching the engine up to operating temperature for some time, you ....

https://www.boatingmag.com/boats/how-to-properly-winterize-marine-diesel-engine

Above is an article on winterizing your marine diesel engine(s). It doesn't recommend starting your engine periodically. It sounds like the proper strategy is to winterize the engine (and systems) and let it sit.

If you don't want to winterize it and cheat by occasionally starting it that is another issue. It doesn't sound like that would work. Continual usage during the winter would be a better strategy, IMHO.

To avoid condensation keep your tank full over the winter. Treat it with a biocide/stabilizer and don't start it until next season. Bleed fuel lines and replace filters. It also recommends changing the oil before storing for the winter.

That's my takeaway from the article. I suggest you read it for yourself. Always better than listening to others.

Xsbank said:

This old chestnut is as bad as discussing anchors or stern thrusters. If you can’t be bothered to read the reams of blather about this topic in the search function, go have a nice rum or go for a walk until the urge to write some anecdotal nonsense about your defining moments in boating goes away. Happy New Year!

Click to expand...

:lol:

Da Book rules.

Get a copy of the maint manual for your engine.(It should already be onboad.)

Read what the mfg sez about storing the engine.

"Out of service for over 30 days" is usually covered .

Out of service is NOT winterizing, which is usually a far larger procedure.

While Da Book is king , many folks do not know the next time the boat will be used.

I have always thought an ether cold weather starting device could be used with fogging fluid as a protection on shutdown.

We only start the engine when ready to depart , give it 30-60 seconds and get underway at idle.

I advise my local guys (NC) where boats are mostly left in the water over the winter to start their engine up maybe once a month to get oil smeared around in cylinder bores and to knock any corrosion off valves. Just start them up and raise idle to say 800 for a couple minutes. No need to warm all the way up as dockside that simply will not happen.

I have seen rusted cylinder bores and rusty valves. I don't worry about the bearings, or engine sludging up or fuel dilution in a few five minute runs.

Very important on Detroit two strokes as a few cylinders will really breath when sitting. A little block heat on the DD's solves the liner corrosion issue.

If boat is fully mothballed for the winter, then don't worry about it. Usually up north the air is super dry in the winter and the corrosion issue is much less.

Down here we get wild swings in temp and humidity during the winter. When a warm front comes, right before is a good time to get a little heat in the engine. Otherwise when the warm air comes in, engine looks like a cold beer in August. Dripping wet.

Again, block heat helps but the arctic 1000w units are super overkill. No need to keep it 120F. 250w will keep it 10-20F above ambient and condensation will not happen.

dirtdoc1 said:

https://www.boatingmag.com/boats/how-to-properly-winterize-marine-diesel-engine That's my takeaway from the article. I suggest you read it for yourself. Always better than listening to others.

Click to expand...

Humm, drain the fuel lines and use Stanadyne purchased through Defender the article says. Along with a few other odd statements and not saying for what weather the undefined motor is being "winterized" - maybe indeed XS's chestnuts be rested.

Ski in NC said:

I advise my local guys (NC) where boats are mostly left in the water over the winter to start their engine up maybe once a month to get oil smeared around in cylinder bores and to knock any corrosion off valves. Just start them up and raise idle to say 800 for a couple minutes. No need to warm all the way up as dockside that simply will not happen.

I have seen rusted cylinder bores and rusty valves. I don't worry about the bearings, or engine sludging up or fuel dilution in a few five minute runs.

Very important on Detroit two strokes as a few cylinders will really breath when sitting. A little block heat on the DD's solves the liner corrosion issue.

If boat is fully mothballed for the winter, then don't worry about it. Usually up north the air is super dry in the winter and the corrosion issue is much less.

Down here we get wild swings in temp and humidity during the winter. When a warm front comes, right before is a good time to get a little heat in the engine. Otherwise when the warm air comes in, engine looks like a cold beer in August. Dripping wet.

Again, block heat helps but the arctic 1000w units are super overkill. No need to keep it 120F. 250w will keep it 10-20F above ambient and condensation will not happen.

Click to expand...

Bingo

Ski in NC said:

Down here we get wild swings in temp and humidity during the winter.

Click to expand...

You got that right! We moved from Manteo to Morehead City last year on a 72 degree day in mid February!

We run our motor up to full temp several times over the winter... because we go boating in NC Not exactly the same thing for the same reason as the OP, but hey, it works for us.