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Starting diesel in freezing temp....

Jun 28, 2014
Hunter 31 Fernandina Beach
I lived in North Dakota most of my life. started many large diesel engines in very cold weather. I don't like the WD-40 idea, some do. the space heater is a good direction but not so fond of the heater in a cold boat idea. I like the shore power and heat the hot water heater. as well as a heat lamp an infrared bulb for 12 hours the engine will be toasty just like the summer. open the engine compartment and shine the light on the block. no ignition source and it will warm the block. It works in the shed in sub zero conditions. just block the wind and inside the cabin should be no wind over night. good luck.
Jan 22, 2008
Beneteau 343 Saint Helens, Oregon OR
We've had a few nights in the teens and 20's this winter. Started our 3YM30 in the 20's without a problem. However, when below freezing is in the forecast I turn the water heater on - both to get some heat in the engine compartment and to have some warmth in coolant. Also starts in first turn.
Oct 22, 2014
CAL 35 Cruiser moored EVERETT WA
29 degrees for several days. Turned on space heater, blew the warm air into the engine compartment for about 2 hours while I finished my morning coffee... engine cold but fingers did not stick to engine. Water in engine cold but not frozen. Fired up the 50 year old Perkins 4.107 no glow plugs... took off on the second rotation. Blew out a bit of carbon/soot and then began to warm up and purr like she always has.
Aug 28, 2015
Oday 28 St Joseph, MI
Why don't you just talk to the buyer. Tell him/her/it that you have never started the engine in the winter so you're going to put a heater in the engine compartment to raise the temp to a more spring like number. You could also explain that there is always the possibility that something has happened over the winter so you're going to start it before the survey so you can have it running properly for the survey. Tell him he is welcome to come to the "pre survey start up". I would have no problem with a seller doing that.
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May 24, 2004
CC 30 South Florida
Yanmar engines do not have glow plugs and they heat up and ignite the fuel/air mixture by compression. At startup compression will build up gradually with successive revolutions. Cold oil and cold batteries will conspire to slow down the cranking process. As the engine turns exhaust valves open allowing for some loss of compression build up and for this reason and to stay ahead of the curve the engine needs to crank rather fast to reach the desired compression which will cause ignition. Open the throttle 3/4 and combine your battery banks for maximum power and crank away.
Jul 26, 2015
Watkins 29 Ft. Lauderdale
Now Im not suggesting that you do this.. it would be damaging to a diesel to even try... but in the old days, the old radial reciprocating engines on airplanes, had the capability of injecting gasoline directly into the oil resorvoir to thin the viscosity of the oil so that it would possible to start the engines after sitting in the cold all night. Think about that for a few seconds... putting 115 octane gas into your oil tank... that should make some of your personal parts pucker.


Jan 6, 2006
Beneteau 423 Mt. Sinai, NY
the main thing I was worried about was the oil not circulating quick enough. Left the batteries fully charged back in November so they are fine. Heater in the cabin to keep everybody including the engine warm will be a bonus...... just going to freeze my hand off while adjusting the water flow into the bucket for the fresh water intake!
As always thanks for all the input!

Jan 24, 2017
Chrysler C26 Lake Sakakaweea
What weight oil are you using? 32deg is not cold. Unless you are using 20/50 you are fine
Nov 18, 2016
Ericson 38-200 Honolulu
I like the idea of using a water heater, and (while heating the water) slack your fresh-water pump belt. Then fit a bolt-head in the center of the pump pulley and use an electric drill to circulate the heated water for a couple of minutes (or more) before cranking; (remember to re-tighten the belt).


Oct 13, 2008
Hunter 36 Hampton
Yanmar engines do not have glow plugs and ....
The 3YM30 in our '08 h36 has glow plugs that are energized each time the start key is turned to engage the starter. There is a glow plug relay that is energized by the key switch to supply current via heavier wiring. There is also a "glow" position on the key switch if you want to get the glow plug warmed up for a few seconds prior to starting. No glow plugs in our 2GM20F from '91.
What is the average life of a glow plug? I haven't tested them to see if they are functioning. Engine starts ok.
Nov 18, 2013
Catalina 310 Campbell River
This is used up in the artic, with a Tiger torch under the oil pan for 5-10 minutes will heat up the oil and engine block longer if below -40.