6LYM-UTE Yanmar white exhaust smoke

jplob96

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This is a 1995 engine. Conclusion from a previous thread was that the smoke was caused by cold air, fuel, coolant and oil. Does anyone have any experience with heating blankets, block/coolant heaters or oil pan pad heaters? This was the solution from Tony Athens. Warm it up and the smoke will go away.
 

BillD

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Wolverine oil pan heater or a 250W block heater.
Run either 24/7.

I'm pretty sure if you call Seaboard Marine (Tony Athens) he'll have a suggestion/solution and most likely the components you need in stock.

Wolverine Oil Pan Heaters for Cummins Marine Diesel Engines

I have 250W block heaters on the Cummins 370s that are plugged in 24/7 when the boat is in the water.

On the new Cummins 370 going into the 25 T Jason I'll be using the #18 Wolverine Pan heater.

It is easier to install the the pan heater BEFORE the engine is installed.

On your Yanmar...it may be simpler to install a block heater.

FWIW, Bill D
 

captjohn

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Unless you have a coolant leak, white smoke is unburnt fuel. It indicates a cold engine or worn rings, or both. If it runs fine when things warm up outside, cold engine. As mentioned, block heaters really help if it's due to the engine being cold.
 

jplob96

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Hi Bill, Tony Athens web site is where I got the info for adding some kind of heater. A oil pan heater would be nearly impossible to install. It looks like a block heater would be the best choice. I think there are magnetic ones you just place on the side of the block. I don't know how well they work, any experience or info on these? Next step may be to contact Tony or Mack Boring. Thanks, John
 

harmuthmarine203

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all the 6ly's smoke when its cold or idling alot its because the cooling systems on those motors are very large and are built and designed to cool that motor when its pushing 370hp out of a little block and the now that engine dose 480hp with electronic govnor. So when the motor is just siting there idling the thermostat says closed and the coolant in the engine is staying below the thermostats opening temp beacuse the raw water is super cooling the coolant.
with a few motors i have changed the coolant mixture to 70% water and 30 % antifreeze instead of the typical 50/50 mixture and it seem help
 

jplob96

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That is interesting, did not know the 370hp and my 315hp is the same block. A 70/30 mix for the coolant would not work unless the system is drained when engine is winterized as temps reach below zero. Anyone ever use a heating blanket? From what I understand you place the blanket over the engine and plug it in. Only one side of the blanket gets hot.
 

petrel

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I would install a block heater and use it as much as possible. In addition to doing away w/ the smoke, it will keep your engine room dry and cut down on corrosion that would otherwise occur in a damp engine room b/c of temperature swings.
 

harmuthmarine203

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Even diluting the antifreeze would still protect your engine down to -20deg Fahrenheit and i varified that with my refract-meter

also are you using any additives in your fuel with alot of your customers use a cetane booster and it seams to help the white start up smoke and idle smoke, by increasing the cetane content the fuel burns more fully which eliminates the smoke
 
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harmuthmarine203

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Block heater- done.
A block heater will only solve initial start up and will not help up here in the northeast during the spring and fall when our waters are below 50 and most of us are trolling at idle and the motor cools down after a run and tend to run under temp after troll for a while that with the combination of low cetane fuel will make those 6lys smoke its the nature of the way they inject the fuel
 

harmuthmarine203

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Im not confused by the motors the 6lp 315 do cold smoke sometimes but, if the air intake heaters are working in the intake manifold they tend not to except of maybe a puff at start up the 6ly315 (before the electronic models) tend to cold smoke when the water is cold or when idling a lot like trolling

i personaly would never recomend a heating blanket i have seen to many fail and catch on fire or on the verge of catching on fire im with Petrel if you want to keep ur engine warm and make the engine start up easier put a block heater in or even better at a "hot start " to ur coolant system
 
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