I have 2006 Hunter 38 and I'm in the process of Winterizing my Yanmar diesel. What is the best way to run some fresh water and antifreeze through the raw water cooling system. I heard this should be done witht he engine hot for the antifreeze to be effective?
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Bob...
my 3GM30F in my H34 has a "T" fitting ahead of the raw water pump, with a ball valve and male hose connection on the T-d side.
To antifreeze the engine I close the raw water intake valve, hook a 5 gallon bucket with a ball valve/male hose thread on its side at its bottom to the raw water hose (use a washer hose line with two female ends), pour two gallons of the pink (or purple) antifreeze in the bucket, open the bucket valve to allow the antifreeze to flow, and start the engine. I shut it down just before it empties all the antifreeze in the bucket. After the antifreeze is done, the oil/filter gets changed, and the raw water impeller gets removed.
This is done just before the boat is put on the hard, but could be done on the hard as well. Once on the hard, I rehook up the bucket, open the raw water intake, and let gravity pull another gallon throught the hoses and raw water strainer. Close all valves and you're done for the winter.
my 3GM30F in my H34 has a "T" fitting ahead of the raw water pump, with a ball valve and male hose connection on the T-d side.
To antifreeze the engine I close the raw water intake valve, hook a 5 gallon bucket with a ball valve/male hose thread on its side at its bottom to the raw water hose (use a washer hose line with two female ends), pour two gallons of the pink (or purple) antifreeze in the bucket, open the bucket valve to allow the antifreeze to flow, and start the engine. I shut it down just before it empties all the antifreeze in the bucket. After the antifreeze is done, the oil/filter gets changed, and the raw water impeller gets removed.
This is done just before the boat is put on the hard, but could be done on the hard as well. Once on the hard, I rehook up the bucket, open the raw water intake, and let gravity pull another gallon throught the hoses and raw water strainer. Close all valves and you're done for the winter.
Bunk is true. The antifreeze does not need a warm engine to protect against freezing. However, and here's the rub, running your engine for a short period can cause internal condensation that will sit in your engine during the off season.
It is always best to run the engine long enough at full operating temp to burn off any start up condensation. I usually winterize my engine while it is still in the water so I can run it long enough to burn off the condensation.
Just a word of caution about the antifreeze:
Before you suck any antifreeze in through the sea water strainer or engine consider the following:
#1 The -50f pink stuff (propylene glycol) is not intended to be diluted nor is the -60 or -100.
This quote is from Camco one of the largest producers of "RV" antifreeze.
#2 Your engine has a strainer (unless you by-pass it and drain it), hoses, HX and wet exhaust system that will already be full of water. One or two gallons of -50 pink stuff may not sufficiently prevent a freeze up if diluted with the 1+/- gallon of fresh water probably already in the system.Camco said:
#3 If your vessel has engine driven refrigeration, like a Sea Frost unit, be sure to drain the refrigeration HX before sucking in the antifreeze as this alone contains at least a gallon of water.
Here in Maine we can see -20f to -30f. Sometimes for up to a week at a time. It is critically important that the -50 antifreeze NOT be diluted and that it can withstand the temps in your region. You don't want to be buying a new HX, Water Lift or raw water pump..
I actually drain all hoses, the wet exhaust water lift, sea strainer, engine HX and my Sea Frost HX before sucking any antifreeze through. This allows me to buy less antifreeze as it is not getting diluted. Up here in Maine I use the -100 stuff for a couple bucks more but only because of our potentially really low temps.
Nearly every spring I hear of someone at the local yards who froze their engine, usually a DIY. Cha-ching $$$$$$$$.. Merely seeing pink out the exhaust does not tell you what the freeze point is or how diluted it has become. Engines & parts are expensive, antifreeze relatively cheap. I would suggest either running more through, like four to five gallons, or drain the system before sucking it in or check the freeze point of what is coming out the wet exhaust by catching it with a cup.
Of course if you're in MD or NJ this might not be a concern but in areas where it gets to 20 below+ it is a real concern as even antifreeze can freeze, especially stuff that has been diluted with fresh water..
maine sail, do you use rv antifreeze in the engine? i have been using the green stuff, but if i could use the rv i certainly will. my engine takes two gallons and i can save a few bucks.
mike
mike
No & Yes?
No I do not use RV antifreeze "in" the engine, as in using it for my fresh water closed system antifreeze. Yes, I do use the RV stuff for winterizing the raw water side of the engine ONLY. I use the RV stuff rated for engines, it supposedly has more rust inhibitors, and is rated at 100 below as opposed to -50. The pink stuff should be fine in the raw water side provided it does not get diluted. The burst point is -50 for pink stuff, but if it gets diluted that burst point rises quite rapidly..
Sucking the green stuff through the raw water side and dumping it into the lake or ocean is not such a good idea as it is considerably more toxic..
Always use engine antifreeze (Peak, Prestone etc.) for the sealed system and RV type for the raw water side winterizing..
Maine Sail...
you're right about the winter temps down here in Maryland being not normally as severe as yours. However, every few years we seem to get temps that rival yours for a week at a time or more. I'm suspecting with snow in the Rockies already that this could be one of them and will be using the purple stuff for raw water protection this year.
Also, I winterize the engine upon arrival at the winter storage marina on the day the boat gets moved there, so the engine is hot when antifreeze is run in and the oil/filter change is done.
I also will follow the suggestion on another thread about blowing out my water lines this year for the first time for the same reason.
you're right about the winter temps down here in Maryland being not normally as severe as yours. However, every few years we seem to get temps that rival yours for a week at a time or more. I'm suspecting with snow in the Rockies already that this could be one of them and will be using the purple stuff for raw water protection this year.
Also, I winterize the engine upon arrival at the winter storage marina on the day the boat gets moved there, so the engine is hot when antifreeze is run in and the oil/filter change is done.
I also will follow the suggestion on another thread about blowing out my water lines this year for the first time for the same reason.
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