Freeze/Drain Plugs on a 3.0L Mercruiser? Filling with Anti-Freeze and Winterizing

[enginesilo]

I've winterized my 3.0L Mercruiser for at least 5 seasons now and has gone well every time so far. I had a question about freeze plugs or drain plugs on the engine.

I never pull any drain or freeze plugs. My engine has what is called a "Single Point Drain System" that supposedly drains the seawater section of the engine. This is what traditional freeze/drain plugs do, right? I'm guessing this is doing the same job but much easier.

I then follow the procedure of removing the 2 hoses at the thermostat housing and pouring anti-freeze into both sides until I see it pour out.

Any tips on this appreciated.

 

[HT32BSX115]

Re: Freeze/Drain Plugs on a 3.0L Mercruiser? Filling with Anti-Freeze and Winterizing

I've winterized my 3.0L Mercruiser for at least 5 seasons now and has gone well every time so far. I had a question about freeze plugs or drain plugs on the engine.

I never pull any drain or freeze plugs. My engine has what is called a "Single Point Drain System" that supposedly drains the seawater section of the engine. This is what traditional freeze/drain plugs do, right? I'm guessing this is doing the same job but much easier.

I then follow the procedure of removing the 2 hoses at the thermostat housing and pouring anti-freeze into both sides until I see it pour out.

Any tips on this appreciated.

Howdy,


No such thing as "Freeze Plugs" They're CORE-plugs. The holes are for removing casting sand in the casting process.........If you want to give them a "name", you could call them "Freeze-Damage" plugs. Because if they pop out, you probably have freeze damage!!


The single point system is dangerous to use after the engine is brand new because the hoses and valves get plugged up with rust flakes. This can block total drainage and leave water in the block which WILL cause freeze damage. (read that as: "Cracked Block")



Your best bet is to remove the single point system, remove the connections at the block, and poke the holes with a piece of wire/screw driver etc to clear the holes of debris and rust flakes. Then remove the big hose on your circulating pump to drain water in that and any other hose with a heat exchanger in-line (power steering cooler)

THEN remove the drains at the manifold and poke wire in them too. ensure everything is drained. After you do that, you can pour anti-freeze in there if you like.

Regards,


Rick

 

[Starcraft5834]

Re: Freeze/Drain Plugs on a 3.0L Mercruiser? Filling with Anti-Freeze and Winterizing

Remove plug(s) (2) on right side of block back rear, let all water drain out, above that is manifold plug, remove that and let all water drain out.. remove top water hose going into theromostat, assuming you have removed the two engine block plugs first and let it drain, you likely not to see any water at all in the top hose when u take that off and look,, use a air compressor if u want and blast air through top hose in the system, I did that and got no further water out bottom of block.. once water is out,, your done,,, wasting $ on antifreeze is not needed, if you will sleep better at night buy it and put it in... no water, no ice........ even if there's a small amount laying in there, freeze expansion wont damage anything, when blocks full of water, freeze cracks em........... good luck!

 

[81 Checkmate]

Re: Freeze/Drain Plugs on a 3.0L Mercruiser? Filling with Anti-Freeze and Winterizing

If your 3.0 is like mine with the two blue hoses that are conected to a bracket in front of carb. What the manual says to do is disconect the two hoses at the bracket and push the hoses down to bilge with the tee handle to drain the block and manifold.

What i do is reach down the side of the motor and disconect the hoses there...they have the quick disconect connection. Pop them off and poke the fittings in the block and manifold to get the crud out. 2 on block and 1 on manifold and i just leave the hoses off till spring.

Then you can the rest of your procedure.

Thats what i do and has worked the last 3 years.

 

[bmowers]

Re: Freeze/Drain Plugs on a 3.0L Mercruiser? Filling with Anti-Freeze and Winterizing

If your 3.0 is like mine with the two blue hoses that are conected to a bracket in front of carb. What the manual says to do is disconect the two hoses at the bracket and push the hoses down to bilge with the tee handle to drain the block and manifold.

What i do is reach down the side of the motor and disconect the hoses there...they have the quick disconect connection. Pop them off and poke the fittings in the block and manifold to get the crud out. 2 on block and 1 on manifold and i just leave the hoses off till spring.

Then you can the rest of your procedure.

Thats what i do and has worked the last 3 years.

Is your boat garaged and if not does the boat actually freeze where you are storing it?

So, no antifreeze I take it?

Thanks
Brian

 

[81 Checkmate]

Re: Freeze/Drain Plugs on a 3.0L Mercruiser? Filling with Anti-Freeze and Winterizing

Brian.....I do not put any antifreeze in. I just leave the hoses off.

We have it stored in a barn...And yes it does freeze here in south west Ohio.

Hope that helps.