Winterizing kits are block buster kits

[rolmops]

Some of you may have bought a winterizing kit that uses a 5 gallon tank in order to replace all water in the block with rv antifreeze. You are supposed to warm up the engine until the thermostat opens up and then channel the antifreeze into the engine by shutting off water and running the anti freeze into the block.

This is a terrible idea. When the cold antifreeze hits the thermostat it will close the thermostat very soon afterwards and although a bit of antifreeze will indeed get into the block (usually enough to make the color of the cooling water change to pink) it will not totally replace the water in the block and the chance of this mix freezing over and bursting the manifolds or the block is quite high.

Marinas that use this system usually use the antifreeze in a closed system and the stuff warms up . This keeps the thermostat open and the system will work well. That would mean that you will have to fill a barrel with the AF in your back yard and run the system that way.

It is just better to drain all the water and make sure it is all out . You may even want to use air pressure to make sure.

[sherman brown]

5 hours ago, rolmops said:

Some of you may have bought a winterizing kit that uses a 5 gallon tank in order to replace all water in the block with rv antifreeze. You are supposed to warm up the engine until the thermostat opens up and then channel the antifreeze into the engine by shutting off water and running the anti freeze into the block.

This is a terrible idea. When the cold antifreeze hits the thermostat it will close the thermostat very soon afterwards and although a bit of antifreeze will indeed get into the block (usually enough to make the color of the cooling water change to pink) it will not totally replace the water in the block and the chance of this mix freezing over and bursting the manifolds or the block is quite high.

Marinas that use this system usually use the antifreeze in a closed system and the stuff warms up . This keeps the thermostat open and the system will work well. That would mean that you will have to fill a barrel with the AF in your back yard and run the system that way.

It is just better to drain all the water and make sure it is all out . You may even want to use air pressure to make sure.

I do have a question. why would the cold antifreeze close the thermostat and not the cold water from a hose to your muffs?

 

I have never done anything other than open the petcocks on each side of the block and manifolds. I did it this way for 25+ years when I owned a Mercruiser.  I did remove the water hoses that runs down each side under the motor and the hoses going to my thermostat housing. and not once did I worry about it freezing and it worked every year but 1.

 

ugs saved my motor. and that was the year my freeze plugs saved my motor. sand had settled in the pipe and stopped it up and all the water didn't drain out of that side. LESSON LEARNED, I removed the pipe and started using a petcock only even though it was a bi*** to get to and open.

[rolmops]

The water and the antifreeze do the same thing. Water gets hot in the block, the thermostat opens and when the incoming water cools the block, the thermostat closes again. Now the antifreeze just flows by but does not go into the block. You have only five gallons of antifreeze and only some of it reaches the block. You would probably need at least ten gallons to fully replace what's inside the block because of the opening and closing  action of the thermostat.

[Zinger11]

Before I even start winterizing my block I open the 2 drain valves above the oil pan and make sure they drain. Sometimes I have had to shove something to unplug them because dirt will collect on the bottom of your block causing water to get trapped or block circulation 

[lost a lure]

You're over thinking. Put your Nike's on and just do it.

[Shakemsam]

On 10/22/2024 at 6:24 PM, lost a lure said:

You're over thinking. Put your Nike's on and just do it.

Exactly!

 

[Bozeman Bob]

On 10/21/2024 at 12:33 PM, rolmops said:

Some of you may have bought a winterizing kit that uses a 5 gallon tank in order to replace all water in the block with rv antifreeze. You are supposed to warm up the engine until the thermostat opens up and then channel the antifreeze into the engine by shutting off water 

Marinas that use this system usually use the antifreeze in a closed system and the stuff warms up . This keeps the thermostat open and the system will work well. That would mean that you will have to fill a barrel with the AF in your back yard and run the system that way.

It is just better to drain all the water and make sure it is all out . You may even want to use air pressure to make sure.

       A closed system in the marine world means it has a heat exchanger and has anti- freeze in the block , just like a car . Open system the engine is cooled by lake water .                                                               Take the thermostat out if you think that is closing up to quickly.  Yes , opening the petcocks on each side of the block and draining the water is the way to go , Air doesn't freeze the last time I checked . One thing not to overlook is the cylinder shaped in line , raw water , heat exchangers for either the engine oil or power steering pump . Usually it is attached underneath or on the lower side of the engine . It has a drain plug on the bottom of it , usually a square drive bronze plug . Or remove the hose from at least one side of the exchanger and let the water drain out . I've seen the end caps on them get " blown off " by freezing water expanding them . Again , air doesn't freeze 

[sherman brown]

if I ever decided to use the kit I would go to the trouble to drain the block and the exhaust manifolds first then add the antifreeze. most of the comments say they drain the block but no one mentioned draining the exhaust manifolds. or maybe the newer boats doesn't have the petcocks at the rear of the exhaust manifolds.

[Bozeman Bob]

5 hours ago, sherman brown said:

. or maybe the newer boats doesn't have the petcocks at the rear of the exhaust manifolds.

  The risers that I have purchased in the last few years do not have drain plugs . The old ones did have them .  I have never had to replace the exhaust manifold itself , which usually have petcocks on the bottom of them . 

[sherman brown]

16 hours ago, Bozeman Bob said:

  The risers that I have purchased in the last few years do not have drain plugs . The old ones did have them .  I have never had to replace the exhaust manifold itself , which usually have petcocks on the bottom of them . 

I always open those petcocks on my exhaust manifolds. never had to replace the manifolds myself. Have a great winter so you can go get them come spring.

[lrg355]

I currently have a 4.3 Mercruiser which has 5 drain plugs. Pull them out one at a time and blow compressed air into the drain plug thread area. A hose with a rubber cone for good sealing against the hole in the block and a valve upstream does the trick.  A few blasts in each hole and you will be amazed what comes out.  I run in a muddy area on Sandy Pond and it sucks up a lot of mud especially late in the season. Been doing it this way for over 40 years with no problems.  Had friends that just pulled the plugs or didn't do the antifreeze properly and had cracked blocks.