Another winterization question

JR Bates

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I have watched quite a few YouTube videos on winterization. One in particular stated that the creator of the video called a professional shop in northern Minnesota. Who told him they drain the antifreeze out of the engine after a thorough A-F flush out. I think either way should be fine is there a preferred way? Maybe it is because it is much colder in N. MN. Than the S. KY area. Where my boat will be stored. New to boating just shooting for the preferred method.
 

Lou C

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Manually drain, poke all the drain holes
put gasket sealer on the drain plug threads
replace plugs
manually back fill the engine from the top end of the big hose that connects to the thermo housing
fill the manifolds via the feed hoses from the thermo housing
reconnect hoses
leave AF in because the whole point of it, is to reduce corrosion.
Make SURE to use good enough AF for your coldest temp. I do not use -60 or -50 they get hard at about 10*F. I used -100 or mix a batch of Sierra PG antifreeze for -26 freeze protection. That's more than good enough where I am.
 

Chris1956

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Most I/O Engines are either FWC (antifreeze) or RWC (raw water)cooled. A lot of FWC engines don't need any winterizing, as the engine block is full of A-F and the risers are self draining and raw water cooled. However it is important to determine what you have, and winterize the parts of the engine that need it.

If you do have a RWC engine, all water must be drained. Vee engines usually have 2 drainplugs on the block and 2 on the manifolds. There can be water in the power steering cooler and the risers, as well.
 

Lou C

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Ahh with a FWC engine your heat exchanger (expensive to replace) has raw water in one half of it and must be drained as does the raw water intake hose!
 

rallyart

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I just drain all the water from my system. Then, with my boat still on the trailer I the it for a bit of a drive to slosh any water still in the engine or hoses, or heaters in my case, out. Fifteen years of never using antifreeze in Canada and there has never been a problem.
If you are using an RV antifreeze you will find it turns into a slush rather than a liquid when it gets really cold. That's why it might be nice to drain it if you get extreme cold.
 

JR Bates

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Most I/O Engines are either FWC (antifreeze) or RWC (raw water)cooled. A lot of FWC engines don't need any winterizing, as the engine block is full of A-F and the risers are self draining and raw water cooled. However it is important to determine what you have, and winterize the parts of the engine that need it.

If you do have a RWC engine, all water must be drained. Vee engines usually have 2 drainplugs on the block and 2 on the manifolds. There can be water in the power steering cooler and the risers, as well.
I do have a RWC 2000 5.0 merCruiser. It has the 5 blue plastic drain plugs. I pulled them & drained all water after a little drive on the trailer. Hoping to get all the water out. My plan now is to run the engine on muffs until the thermostat opens. Shut down attach a 5 gallon bucket with hose to the muffs restart quickly. When the anti freeze gets down to about a gallon &1/2 half start fogging through the carb. Watching to insure I don’t run out of A-F prior to shutting down. I have already added the fuel stabilizer before my last trip & refilled the tank added the appropriate amount of stabilizer for the new gas. I am using -100 marine A-F. So I guess leave in the A-F for anti corrosion protection. Should I use the drain & back fill method or my 5 gallon bucket plan?
 

JR Bates

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I do have a RWC 2000 5.0 merCruiser. It has the 5 blue plastic drain plugs. I pulled them & drained all water after a little drive on the trailer. Hoping to get all the water out. My plan now is to run the engine on muffs until the thermostat opens. Shut down attach a 5 gallon bucket with hose to the muffs restart quickly. When the anti freeze gets down to about a gallon &1/2 half start fogging through the carb. Watching to insure I don’t run out of A-F prior to shutting down. I have already added the fuel stabilizer before my last trip & refilled the tank added the appropriate amount of stabilizer for the new gas. I am using -100 marine A-F. So I guess leave in the A-F for anti corrosion protection. Should I use the drain & back fill method or my 5 gallon bucket plan?
I do have a power steering pump like on an old Chevy V-8 it is a 2000 bayliner not sure if I have any water cooled power steering cooler to worry about?
 

Lou C

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Drain and back fill is definitely safer and the way to go
 

tpenfield

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No real need to pre-drain the cooling system (via the blue plugs) if you are going to run the engine on the muffs to pre-heat it and open the thermostat. Keep in mind that a fair amount of the AF will go straight out to the exhaust risers and never go through the engine block, so more AF is better.

It is better to drain the engine and manifolds after running the AF. Since you plan on using the -100˚ F stuff you should be OK. You can refer to the diagram below that shows how a typical marine engine cooling system works . . .

Marine-Engine-Cooling-System1B.png
 

Lou C

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I do have a power steering pump like on an old Chevy V-8 it is a 2000 bayliner not sure if I have any water cooled power steering cooler to worry about?
They pretty much always have a cooler in line with the raw water intake hose, sometimes behind the engine right where the raw water intake hose comes out of the transom mount. If they are mounted vertically or diagonally they may self drain but if it’s mounted horizontally they have to be drained. What I do with mine is put the outdrive down and disconnect the raw water intake hose at the thermostat housing. Hold it down to drain then hold it up and fill it with -100 marine AF till the AF runs out the drive water intakes. There is a drain on it but it’s a finger buster to get at.
 

Lou C

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About the other question I like to drain and backfill because:
You know it’s totally drained
AF will not be diluted
You can leave the AF in to reduce internal corrosion, that’s the whole point of using AF, and in later Mercruiser manuals that’s how they say to do it.
If you are located where it gets really cold like zero or below use -100 for best protection.
While some feel no need for AF and this may be true in fresh water regions I can tell you I don’t see any rusty water exhaust after I start mine up in the spring.
 

Chris1956

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Running the motor in a bucket of antifreeze is a really bad way to winterize it. When you do that you get some amount of antifreeze, into some part of the engine, at some strength. Very dangerous for the engine.

My recommendation is to drain it completely and then fill each hose with some full strength antifreeze until it emerges from the drain holes or intake. Now install the plugs and fill each hose until the block is full and the manifolds and risers allow some a-f to escape via the exhaust.

Drain the engine and manifolds in the spring and capture the antifreeze for reuse.
 

ahicks

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The bigger point here is the fact that a lot of the garden variety RV anti freeze (pink stuff) can freeze hard enough to cause damage if it gets cold enough.

RV anti freeze is NOT all the same.
 

Lou C

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-100 or mix up some Sierra PG; that’s what I’ve done for close to 20 years.
time to winterize.jpg
 

JASinIL2006

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If you're boating in salt water, I suppose there could be benefit to filling with antifreeze, but I really doubt it makes much of a difference for fresh water boaters.

If you boat in fresh water and it makes you feel better, drain the engine and then refill with antifreeze however you want. You can even walk around the boat and chant incantations against the winter gods. Just make sure to drain the engine thoroughly first; that's what really matters.

Personally, I am comfortable with simply leaving my engine block empty until the spring. That way, I know there's nothing in there to freeze and I've saved a decent amount of money by not buying antifreeze.
 

Scott Danforth

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I do have a power steering pump like on an old Chevy V-8 it is a 2000 bayliner not sure if I have any water cooled power steering cooler to worry about?
if you have power steering, you have a power steering cooler...... always.
 

Chris1956

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A lot of people do not understand the benefit of filling the block with antifreeze. They think it unnecessary.....well it is, if you are positive you got all the water out of the block. So, do you feel lucky?
 

Lou C

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As I said in an earlier post it’s like trailer leaf springs. If you don’t spray regularly with corrosion x or similar they will rust bad in a few seasons here in the salt. If you spray 2x a year they will look good even after 10 seasons. So you flush your engine at the end of the season manually drain and fill it with GOOD antifreeze keeps out air; same concept.
 

Starcraft5834

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back when i had a mercruiser...... i put antifreeze in it and was encouraged by Bondo to just drain the water out and leave it empty.... drained it, that winter was brutally cold, was below zero half the month of february... spring, it was fine.. "air dont freeze"... at least not on earth
 

Lou C

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Yep air doesn't freeze.....but rust never sleeps....
 
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