Winterization - confusion

[Tafflad]

For a number of years my I/O boats have been winterized by a dealer .. and it included filling with anti-freeze mix.
Last year changed boat & dealer ... and his winterizing used no anti-freeze, his comments were that it is better just to drain down.
Now my 4.3MPI has single point draining , so agree that is easy.

However previously I had understood drain down was juts a way of extending season - prevent being caught by sudden frost, but that full winterization & layup should include anti-freeze mix ...

Anybody know what is the official line form Mercruiser ?

 

[tpenfield]

Re: Winterization - confusion

Mercruiser manuals say to drain things . . .

There are 2 schools of thought,

(1) drain

(2) antifreeze

Each method, done properly can be effective. It is easier to do the draining properly than it is to do the anti-freezing properly. Often folks (mechanics included) do not know the amount of antifreeze that it takes to purge the engine cooling system of water so that the concentration of antifreeze is high enough in all parts of the engine to avoid the freeze/crack scenario.

 

[Walt T]

Re: Winterization - confusion

air can't freeze. I do either one, I recommend just draining so there's no worries about toxic disposal of frozen air. As with any method, you must drain power steering and oil coolers, and I recommend removing the large hose from the circ pump and letting all that water out. I did have one circ pump lose a vane inside due to that water freezing, but that's just one out of hundred and hundreds. I had to buy a circ pump that time. Eh, it's only money and he's still a customer.

 

[Tafflad]

Re: Winterization - confusion

Do you mean drain power steering of oil ? .... if so why.

My 4.3 has the large blue 'single point drain' isn't that enough to drain using that.

 

[tpenfield]

Re: Winterization - confusion

No not the power steering oil . . . the power steering oil cooler . . . usually it is in series with the intake line that leads up to the thermostat housing.

 

[TheRussian]

Re: Winterization - confusion

Look up the manual for your engine # online. It is a large document that will take you through the process of performing any kind of repair on your engine. My 1993 4.3LX manual states to drain, no mention of AF. It also illustrates how to do it.

 

[ricohman]

Re: Winterization - confusion

Our local dealer just drains the motors, no A/f needed or added.
And he has been doing this for decades.

 

[BoatDrinksQ5]

Re: Winterization - confusion

I would think that a single point drain increases the chance for a dead spot...

But yeah every manual i have read doesn't mention Anti-freeze.

I would think some dealers would do a Drain, AF, Drain just incase? "up-sell" to customers? or they don't like messing with liability of disconnecting old brittle hoses.... or the pain of playing hoses when it is cold and wet outside....?

 

[bspeth]

Re: Winterization - confusion

If you do use AF you must completely drain the block first.I have read about this at length on this site.If you drain completely AF is not needed.If it makes you feel better then do it.

 

[Tafflad]

Re: Winterization - confusion

just shows if official dealers do it differently, no wonder there is confusion.

 

[Lou C]

Re: Winterization - confusion

If you read a recent Mercruiser manual it does say to drain, and then add AF for corrosion protection. Same thing in my '88 OMC owners manual & factory shop manual.
Keeping the air out by adding AF does reduce corrosion. I don't get rusty water out the exhaust in spring. But how long does it extend the life of the cast iron? Hard to say but my 25 yr old engine (used in salt at least 15 years) has been drained, then filled with AF each winterization. Block/heads have not rusted thru yet. Moored in salt water 6months/ year not flushed till the end.

 

[Tafflad]

Re: Winterization - confusion

Anybody have access to Mercruiser, technician support ... perhaps they could give official line.

I would imagine that Chevrolet never recommend leaving out AF, most manufacturer's recommend AF all year round to prevent corrosion.

 

[Volphin]

Re: Winterization - confusion

Either way is fine. I just drain.

 

[thumpar]

Re: Winterization - confusion

Some Merc manuals say to just drain and some say you can add antifreeze for added protection but the way it is written make is sound like you can do it if it make you feel better.

 

[Lou C]

Re: Winterization - confusion

The main thing is to properly get all the water out and probe all the drains. If you've done that then you've avoided the most expensive damage.
Adding AF is fine if you do it the right way, raw water cooling the only truly safe way is to completely drain and then back fill the engine and manifolds just like it says in my OMC owners and shop manuals.
If you use the winterizing tank to suck up AF on a raw water cooled engine without draining the engine first, you gambling that the thermostat is open far enough to let the raw water out of the engine...if you have a slightly sticky thermo, and the engine does not warm up at least as high as the thermo opening temp, you could wind up with manifolds full of AF and an engine full of water, or diluted AF. If you have closed cooling with a heat exchanger then yes that method is fine. Most don't though so be careful....do it right...or pay to get it done right...

 

[mercs4mark]

Re: Winterization - confusion

Here is my question... If you just drain then in the spring on the initial start... What warms up the thermostat to let water into the block to cool

 

[mercs4mark]

Re: Winterization - confusion

Seems to me like you could get into an overheat situation without knowing it since the temp sensor is dry also.

 

[Bondo]

Re: Winterization - confusion

Here is my question... If you just drain then in the spring on the initial start... What warms up the thermostat to let water into the block to cool

Ayuh,... The block fills from below the t-stat,...

The t-stat stops water from leavin' the top of the block, not from enterin' from below,...

 

[mercs4mark]

Re: Winterization - confusion

Gotcha thx

 

[Tafflad]

Re: Winterization - confusion

Just posted this elsewhere:
The manual on my Mercruiser 4.3 (2012) states: after section on how to drain the water

"For additional reassurance against freezing and rust, after draining, fill the cooling system with propylene glycol mixed to manufacturers recommendation to protect engine to the lowest temperature to which it will be exposed during freezing temperatures or extended storage"

Seems pretty clear statement .. drainage will prevent freezing damage, but for assurance and to prevent corrosion you need to fill with AF mix ... and NOT drain that mix out.

What is the correct way to 'fill' to ensure all necessary parts are filled with AF mix ..... in other words where do you pour it in ?