Winterization question(s)....not how to do it

[badrano]

Being a newbie with I/O, I've been reading all the posts about the many techniques boat owners use to winterize their engines. I've read how folks merely use the muffs, others drain the block via the blue drain plugs and then fill the system with anti-freeze, others drain the block and then run anti-freeze using the muffs, etc.

I'm trying to understand the mechanics behind draining the block. I read one post where outboards are self-draining and there is no need to flush the cooling loop with anti-freeze.

When just draining the block using the drain plugs, does every or almost every ounce of water drain out of the block? Basically the design of the drain system is meant to drail all of the water.

Is there a chance that there may be small pockets of water remaining in the block? This may be a reason behind why some folks will drain the block and then run anti-freeze via muffs.

When filling the block with anti-freeze, where is the ant-freeze being filled from? Will the anti-freeze get in to all the nooks of the engine block?

I will stop here and see what kind of responses I get.

 

[Lou C]

As long as you probe all the drain plugs you don't have to worry about a small amount of residual water left in the block. The main thing is to not miss any of the drains, very important. I do fill mine with AF but many think its un-necessary. Merc does say to so it in their manual though. I use either -100 marine AF or I mix up Sierra no tox AF to the right percentage of AF.

 

[badrano]

As long as you probe all the drain plugs you don't have to worry about a small amount of residual water left in the block. The main thing is to not miss any of the drains, very important. I do fill mine with AF but many think its un-necessary. Merc does say to so it in their manual though. I use either -100 marine AF or I mix up Sierra no tox AF to the right percentage of AF.

Where do you fill the AF from. I'm assuming you have to disconnect one of the cooling hoses.

 

[Lou C]

Well I don't know what engine you have, so here's how I do mine:
After the engine is fogged, oil changed etc...
I remove the block drains on both sides, poke em with a pic
I drain the exhaust manifolds
I disconnect the big hose going from the front circulating pump to the thermo housing at the bottom, that drains a lot of water...
Then, I replace the block drains (on mine they are brass plugs so I put some gasket sealer on them)
I reconnect the big hose on the bottom end at the water pump, and disconnect it at the top. Then I put a funnel in the top end and fill that big hose till AF comes out the thermo housing. Now the engine is full, no need to remove the housing either. I fill the manifolds via the feed hoses till the AF runs out on the ground (why you must use no tox). Then reconnect those feed hoses and the big hose at the thermo housing. Lastly I disconnect the raw water intake hose and with the drive down, fill it with AF till it runs out the water intakes.

Keep in mind this is just general, your engine may have p/s or fuel coolers that have to be drained, you really need to look at a manual from the manufacturer.

In my opinion all inboards should have a closed cooling system, open cooling like this is a lousy system, due to the hassle of winterization and the fact that corrosion most certainly happens even in fresh water. These engines were designed by GM to have antifreeze in them, not raw water. Just a cost saving move. If I repower my boat I am for sure adding closed cooling to the new engine. The hassle of getting at all those plugs will be reduced greatly and the engine will last longer and run at a more efficient temp.

 

[dingbat]

I boat well into the winter.
Back in my I/O days I just opened the block drains on the way home at the end of the day.

Once done for the season, I pulled the cover off the thermostat and filled the block with non-toxic anti-freeze. Turn the motor over a couple of time and topped it off again. Put the stat cover back on and left the bolts loose. No problems the 4 years I owned the boat.

Disclaimer: I don't live in a cold climate, per say. Average high temp in January is 43F. Avg. low is 25F. All bets are off for those that live in the tundra

 

[badrano]

Thank you for the detailed steps. Everything makes better sense now. I have a 2009 Merc 5.0 TKS with the 3 point drain system. I've identified the 3 blue drain plugs. From one other post I've read, that poster still disconnects the hoses and drains everything out eventhough he has drain plugs. I can see that as an extra step to make extra sure all the water is out.

 

[ThomW]

So for what it's worth...here it goes:

When I do my I/O, first start the boat on the hose and muffs and let it warm up a few minutes. This is key for a few reasons. First, if you've waited until the season is really over (cold out) it will warm the engine oil and gear lube up, making them drain easier. Secondly, it ensures the motor will start easier when pumping antifreeze through. Shut off motor, and change motor oil and filter.

Next pull all the plugs on engine block. Look up your engine model to ensure you find them all. Some have 2 plugs, some have 4 or 5.
Then, as said above, use a pick or something similar to poke each drain hole (this is because sometimes a flake of rust or something else will be inside the engine, get carried with the draining water and block the hole. It stops water flow, and would appear like water has all drained, but in actuality, it hasn't. After you're sure its drained, put the plugs back in.

Next, I prefer to pump the antifreeze into the motor block via a pair of muffs.

I have a 5 gallon bucket that I modified to winterize my I/O's. Basically, I drilled a hole at the lowest point on side of bucket, and inserted a barbed adapter with a shutoff valve on it that a decent size rubber hose will fit onto . Then, ran a rubber hose from that for 4 feet or so. At the other end of hose, connect an adapter to screw muffs onto it (similar to the end of a garden hose). It's some work, but you do it once, and you'll have it for many years to come.

Then, make sure valve on hose is shut and fill the 5 gallon bucket with with 3-4 gallons of anti-freeze (marine or RV anti-freeze is what I use). Also, be sure its the non-toxic/environmentally friendly stuff. Hook muffs to lower unit. Have a buddy get in boat and start the motor as you simultaneously open the valve to let the antifreeze flow! Run the motor until you see pink (or whatever color antifreeze you use) coming out of the exhaust on the sides of your lower unit. wait until it is a solid flow of antifreeze pumping out. Kill the motor and shut off valve on the bucket. Just watch the bucket of antifreeze and add more as needed if it gets low before you see the pink! Also, make sure to place the bucket up on the boat or on a ladder or something to have it higher than the lower unit (gravity is your friend).

The reason to drain the water first, even though you're filling with antifreeze is to prevent dilution. You don't want the antifreeze mixing with the water and then you have a diluted antifreeze that may freeze in the block and crack something. Using the non-toxic stuff also means you can start it up in the spring and not worry about the antifreeze hurting the lake, pond, or your yard! Also, I believe that the added benefit of having antifreeze in the block--versus just draining it--it to ideally prevent or reduce the amount of rust that might occur if the motor block sat empty (possible a little wet still) throughout the winter months.

Lastly, make sure you drain the gear lube and pump in fresh lube. Although rare, I've seen it happen where lower unit had a bad seal or leak, had some water mixed with gear lube, and BOOM! Froze up during the winter causing more serious issues for the lower unit and gears.

 

[Lou C]

The issue with sucking AF up the outdrive without draining is this:
when the engine is started the thermostat is closed and all the raw water goes out the exhaust manifolds. Only when the thermostat opens enough, will the raw water exit the block. So if you were to use one of these kits without either draining first, or removing the thermostat (too much trouble really) the AF will get into the exhaust manifolds but the block could still be full of raw water because the stat may not open on a cool fall day. Those winterizing kits can be used on a closed cooled engine because it is going to just replace the raw water in the exhaust and heat exchanger with AF. Not on raw water cooled engines though. It is easier and safer for the impeller to simply drain everything, and then back fill with AF through the hoses as I described above.

 

[poconojoe]

I have a 4.3L and it has 5 drain plugs. I can't really tell you why, but I like to leave my drain plugs out for the winter. When I'm done winterizing, I put all 5 plugs plus my garboard drain plug into a ziplock bag and tape it to my steering wheel. I use electrical tape with the sticky side backwards so there's no sticky residue left on the steering wheel.

As far as the non-toxic antifreeze goes, I do the bucket method through the muffs. I added something a little different though.... I use a garden hose "Y" adapter with two garden hose valves. The one common side of the "Y" hooks to the muffs. The bucket connects to one of the other sides and my garden hose to the last. I close the bucket side and fill the bucket with A/F. I open the garden hose side and run the engine until it's warmed up. That's when I switch the valves...turning on the A/F and shutting off the hose.
I've done this and afterwards changed my thermostat and I could see (looking through the thermostat housing) the A/F sitting in the intake manifold. So I think my "Y" hose helps to warm the engine and get the A/F in quick enough before the thermostat closes.
The A/F method to me is just extra insurance which a lot of people feel is unnecessary. Air don't freeze as many say. As long as you get all the water out you technically don't need the A/F.
So, it's up to you...
​​​​​

 

[poconojoe]

Here's what I have...it's a "Y" hose for a washing machine.

 

[Scott Danforth]

Read the factory manual

Change oil and filter
pull drive, inspect u-joints, gimble, etc
Drain drive oil and refill
Drain block/heads/manifolds/hoses. (Not in the manual - hoever important. Prob the drains)

You are now winterized

There is a side-bar note that states: optional, for long term storage, antifreeze may be used for added corrosion protection. Add to system at thermostat housing with a funnel. AF to be -100.

Nowhere in a factory manual does it say suck up AF with the muffs. There is a reason for that

 

[Bondo]

When just draining the block using the drain plugs, does every or almost every ounce of water drain out of the block? Basically the design of the drain system is meant to drail all of the water.

Ayuh,..... This is True, til ya said this next quote,.....

I have a 2009 Merc 5.0 TKS with the 3 point drain system. I've identified the 3 blue drain plugs.

Merc designed drain systems amount to a frozen, busted block, Eventually,......

They don't account for the Crud that's in our coolin' water,......

Strip that "System" off, 'n use a couple of brass pipe plugs in the block,.....
That way, you can poke the crud that builds up there outa the way, so the water can completely drain,......

Air, just don't freeze,.....

 

[Scott Danforth]

Bondo - good point on the 3-point and single point drains.

the systems were added to get better points with consumer report style reviews. (less maintenance points is supposed to be better for the consumer). however in reality, they eventually plug with crud and stop draining.

 

[badrano]

Bondo - good point on the 3-point and single point drains.

the systems were added to get better points with consumer report style reviews. (less maintenance points is supposed to be better for the consumer). however in reality, they eventually plug with crud and stop draining.

Maybe that's why on the one post I read, the owner just pulls the hoses off. It's sounds like a little bit more work, but it sounds like you wouldn't have to worry about any crud plugging up drain holes.

 

[Lou C]

To me it is really sad all the time and engineering money spent on those stupid clog prone systems, when for $500 more on the price you could have a closed cooling system, which is really an improvement and easier to winterize at the same time. As it is today, with the complexity of stern drive engines having efi and cat converter exhaust, its a wonder anyone buys them at all vs modern outboards.

 

[PITBoat]

In my opinion all inboards should have a closed cooling system, open cooling like this is a lousy system, due to the hassle of winterization and the fact that corrosion most certainly happens even in fresh water. These engines were designed by GM to have antifreeze in them, not raw water. Just a cost saving move. If I repower my boat I am for sure adding closed cooling to the new engine. The hassle of getting at all those plugs will be reduced greatly and the engine will last longer and run at a more efficient temp.

+1. I'd kinda like to be able to take mine out once in a while in the off-season too, if the weather is warmish, w/o undoing and re-doing all that.

 

[HT32BSX115]

[h=2]Winterization question(s)....not how to do it[/h]
When just draining the block using the drain plugs, does every or almost every ounce of water drain out of the block?

No, but enough does to prevent freeze damage only IF YOU drain enough to prevent damage. (I.E. poke the holes to get all the rust/debris etc blocking the flow)

Basically the design of the drain system is meant to drail all of the water.

Yes BUT, it only works reliably when the engine is NEW and probably for the duration of the warranty period AND until the engine block and heads start sloughing rust flakes. THEN, it's NOT SAFE TO USE..... because the rust flakes and possibly other debris WILL clog the system sufficiently to prevent complete draining.

Is there a chance that there may be small pockets of water remaining in the block?

YES. but if the block is drained sufficiently, the little bit of water left will not cause damage.

This may be a reason behind why some folks will drain the block and then run anti-freeze via muffs.

It's probably one of the reasons.....another is to "prevent" rust by submerging the exposed iron in AF/water "mix"........BUT, ONLY doing it with "MUFFS" is ONLY completely safe when you have closed cooling.....but then you don't have to drain anything with "Closed" cooling other than the raw water portions of the heat exchanger........ (With "open" cooling, you MUST fully drain and remove the T-stat FIRST before pouring in AF "mix" )

When filling the block with anti-freeze, where is the ant-freeze being filled from?

Most people fill through the T-stat housing......

Will the anti-freeze get in to all the nooks of the engine block?

Maybe, But in areas where pooled water exists, it may NOT completely mix to the concentration required for the lowest temp you'll see ...

I will stop here and see what kind of responses I get.

 

[badrano]

Thanks HT for the detailed answers!

 

[H20Rat]

After winterizing my 4.3l last week, I would HIGHLY recommend pulling the thermostat housing and dumping some pink stuff down there. There was an impressive amount of water that does not drain when you pull the plugs. Probably not contained enough to break anything, but also not really OK with the idea of that volume of water freezing.

 

[Lou C]

After winterizing my 4.3l last week, I would HIGHLY recommend pulling the thermostat housing and dumping some pink stuff down there. There was an impressive amount of water that does not drain when you pull the plugs. Probably not contained enough to break anything, but also not really OK with the idea of that volume of water freezing.

1) did you remove the bottom end of the big hose that connects the thermo housing and the circulating pump? If not this holds a lot of water, and it should be drained at winterization or else your water pump will freeze up and crack.
2) newer (Vortec and up ie 96& newer) have a plug on the front lower left corner of the intake manifold, this needs to be drained as well
3) it is NOT NECESSARY to remove the stat to fill the engine with AF, the way you do it (doing it this way 15+ years) is:
drain from the block drains, poke holes, same with intake drain if you have it, then drain by removing bottom of hose as in #1 above. Then after it all drains, reconnect bottom of that hose. Replace all the drain plugs, put a bit of Permatex Aviation on the threads of metal plugs. Disconnect the top end of the big hose. Now fill via that hose till the engine is full, it will take quite a bit and when AF spurts out of the thermo housing you are done. Re-connect hose no need to remove the thermostat.
4) don't forget to drain the exhaust manifolds
5) disconnect the raw water intake hose at the thermo housing (Alpha and Cobra) or impeller housing (Volvo and Bravo) and point it down in the bilge to drain it. Then with the drive down, fill that hose till AF comes out the water intakes on the outdrive. This will push water out of the hoses and cooler for the P/S system. If there are any low mounted coolers you should drain them manually as directed by the manufacturer.

And PS, I do not use the pink stuff. The -50 or -60 starts to get hard, a bit over zero* F. Try leaving some in the freezer at zero and see what happens, they get hard but do not expand. If you are going to bother to use AF then you should use:
-100 Marine AF with corrosion inhibitors (keep in mind that the -100, -50, -60 is a pipe burst temp, not freeze up temp). I tested the -100 with a propylene glycol hydrometer, it provides freeze protection to about -45*F. Or, you can buy 3 gallons of Sierra no tox PG antifreeze and mix it up with water, a 50/50 mix gives you freeze protection to -26*F. Cheaper than the -100 by a good bit.