Anti-freeze will break your block!

Arminius said:

Last year I followed the Texan with the broken block. I realized there was nothing I could do for him. The best I could do was warn others in advance. That is why I started this thread.

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Then your topic should have been “only winterize your boat if you know how” not “antifreeze will break your block” because that was just nonsense.

Draining ALL the water from the block and leaving it empty will work 100% of the time. As far as rust goes, remember your block sits with lake water in it for the entire summer, there are no rust inhibitors in lake water so whats the big deal with air in the block over the winter.

sea hare said:

Draining ALL the water from the block and leaving it empty will work 100% of the time. As far as rust goes, remember your block sits with lake water in it for the entire summer, there are no rust inhibitors in lake water so whats the big deal with air in the block over the winter.

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"Rust is the common name for the chemicals that result when iron reacts with oxygen and water."

While water is in the block, there is limited oxygen to react with the iron. While empty, any moisture whether residual from the winterization or from humidity will then react with the oxygen in the air to form the rust.

https://www.reliance-foundry.com/blog/what-is-rust

sea hare said:

Draining ALL the water from the block and leaving it empty will work 100% of the time.

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As I mentioned above... Unless there is a clog somewhere. It will APPEAR to have all drained out.

Lazy thinking might allow an owner who figured a drain plug that was too hard to reach could be ignored as antifreeze poured in at the top would diffuse throughout the engine as in the demonstration of colored solutions in Chem 101. That could turn out to be a bad day to be lazy.

The biggest caveat here is your referring to gas engines that are only raw water cooled and not a closed loop system. Someone mentioned using a refactor to see the freeze protection, that does NOT work for open loop systems. This thread may be a little confusing for some thinking it's a closed loop cooling system discussion.

Laid up my 2006 4.3 raw water, Alpha 1 (195 Sport) for winter. Of the 5 blue plugs, one is in front and obvious, next 2 are hanging below the exhaust manifolds mid way back. Final two are a long reach directly below those located on exhausts. Big, about 1/2" and hand tightened with O-rings, these large butterfly handles are easy to identify by feel. Placed them in a red bag tied to steering wheel and that will do it for cooling system. Nice job Mercruiser!

In the event others read this thread and decide to winterize without AF on raw-water cooled engines. The 4.3 Vortec engines have a square headed pipe plug in the front of the intake manifold that also needs to be removed to fully drain it when no AF is being used for winterizing. It is there for a reason and if skipped, is a common place for the intake manifold to crack. It will dump raw water into the block valley once fired back up in that scenario.

I simply don't understand all the cornfusion about blue plugs and pipe plugs and such. The owner's manual is very clear about what to do and where the parts are. All the Merc manuals I ever had also had very clear pictures.

In all my years of boating I only knew one guy that had a cracked block. And he had a dealer do it for him....LOL.

I winterized my 2005 4.3 this past weekend. I removed the 5 blue plugs and probed each passage with a stiff wire. After that I pulled the thermostat off and there was about 1/2” of water in the bottom of the intake. Pulling the square plug on the intake drains the remainder of the intake. Doesn’t hurt to lower the bow when draining the intake.

I do choose to fill mine with antifreeze for the corrosion protection. Likely not needed but can’t hurt either.

Thank you. There was water in the intake manifold even though I had pulled the 5 blue plugs. It was necessary to tilt the bow down by compressing the trailer jack. This black steel plug is on the vertical surface behind the belts. An image of a bulletin is attached. A protruding square 9/16th", I was able to get an open end on it to break it loose. Then I used a 11/16th 12-point without rounding the edges. I replaced with a brass hexagonal (between belt and 2" hose clamp in image) which might get somebody's attention down the road besides being easy to remove. Here's a link to various sources of plug wrenches. https://www.garagejournal.com/forum...-9-16-female-internal-pipe-plug-socket.16560/

I winterized my Mercruiser 4.3 & checked the antifreeze that came out of the engine by catching some in a plastic cup then putting it in the freezer. The solution freezes to a soft slush at +10°F & a hard freeze at -10°F.
I'm good only because I keep my boat inside the garage, I only put the antifreeze through it to be sure it doesn't freeze.

A little trick I learned early on was when a chilly blast come through for a day or 2, then heats back up, put a drop light in engine compartment with a 60 watt bulb in it. Makes enough heat to keep engine above freezing temps, in a pinch.

If you can find them, the rough service bulbs (ones with the coating on them), are the best to use for this.

Bill Curtis said:

A little trick I learned early on was when a chilly blast come through for a day or 2, then heats back up, put a drop light in engine compartment with a 60 watt bulb in it. Makes enough heat to keep engine above freezing temps, in a pinch.

If you can find them, the rough service bulbs (ones with the coating on them), are the best to use for this.

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Back when I kept my boat in the winter water* I would use a couple of the 60w rough service bulbs to keep the freeze away.

*It was in dry storage but during freezing temps I had to put it in the water to keep it from freezing since I didn't winterize. But on really cold days, which are rare here, I'd panic

The One Point system may fail to adequately drain an Alpha drive boat that is in the water. The owner may properly drain the engine for 5 minutes and then close the One Point. Unfortunately, water may flow back into outdrive, through the impeller, up and back down into the block by the siphon principle. Adding anti-freeze immediately after draining is the common and effective solution.

Raising the drive to the trailering position did not defeat the siphon. Placing a "T" in the port under the water pressure sensor at the power steering cooler with a small valve to admit air worked for me. The black 3/16th" hose under the brass hex fitting leads to the valve in the image below.

Funny thing is ( at least for a 5.0 mpi ) that the official merc manual calls for draining the block as freeze protection . No word about AF .

I had a 240da with a raw water cooled 5.0mpi BIII since it was new in 2006 until 2019 and always only drained the block via the plastic distributor , the t-stat vent and the two plugs on the raw water pump.

I freeze protected strictly due to manual.

That worked good for over a decade except the distributor housing was such a silly weak material i burned thru several units turning the plugs in/out - and the housing has a silly price in germany .

In 2018 i had a cracked exhaust manifold midseason on holidays , so after ~ 50 hours after launching the boat after last winter .

Having no other choice because being far away from home , i ordered a certified mercruiser dealer to change the exhaust manifold.

Next midseason , also during holidays , the same new OEM manifold cracked againg wrecking my holidays again . I was so pi**ed off i called the dealer as well mercruiser germany saying that i was ready to sue them if they do not help me.

They tried to cover behind freeze damage and that draining alone does not quarantee full draining.

I gave them a rock solid argument : i freeze protect STRICTLY due to their own manual and i do not care if their central distribution drain is a failed design or not . I cannot drain / poke the manifold manually here. Further i said the manifold ( if freeze damage from winter ) would crack at first launch and not mid season ) .

Mercruiser germany itself offered me they will send a mechanic and parts. They will check the ECM for overheat code storage and measure if the head surface is flat or not . If my engine fails the tests its my bill , if it passes they will cover the parts and labour.

I agreed since i knew i never had an overheat.

Things got really heated up since i was stranded at a small fishing harbour with no slip and no trailer and the merc mechsnic refused to change the manifold on the water. The only option was to order a road crane and lift the boat .

I said fine - but you pay also the crane.

Long story short conclusion : the ecm was clean of oveeheating codes , the head was flat and mercruiser indeed paid the crane , the parts and the labour . They had to agree i did everything to their own written procedures.

Cheers

Apparently the Bravo 2 has a seawater cock and a drain at the pump. My comments are limited to the Alpha drive I have. I did ask the marina mechanic about the One Point system and he responded that it was the best gift ever to mechanics. Poor guy had a cart of tools and antifreeze with many boats left in the water to freeze proof.

Well , the drive has not that much in common if its smart or not to winterize with AF .

Of course you may run into disaster when you just pickup the muffs and let the engine suck in the pink stuff until it comes out of the exhaust - but i guess anybody knows.

A buddy puts the drive into a bucket with antifreeze and lets the engine run for ~20 minutes . The cycling of spitting water out the drive into the bucket and sucking in the antifreeze dilluted the overall concentration but it was enough for freeze protection and he never had an issue . I also agree its better for cortosion protection.

The official method is to only drain the block but it has risks when passages are clogged .

I loved my previous volvo where it was possible to manually drain every part and poke a screwdeiver to make sure nothing is clogged .

aerobat77 said:

Well , the drive has not that much in common if its smart or not to winterize with AF .

Of course you may run into disaster when you just pickup the muffs and let the engine suck in the pink stuff until it comes out of the exhaust - but i guess anybody knows.

A buddy puts the drive into a bucket with antifreeze and lets the engine run for ~20 minutes . The cycling of spitting water out the drive into the bucket and sucking in the antifreeze dilluted the overall concentration but it was enough for freeze protection and he never had an issue . I also agree its better for cortosion protection.

The official method is to only drain the block but it has risks when passages are clogged .

I loved my previous volvo where it was possible to manually drain every part and poke a screwdeiver to make sure nothing is clogged .

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There is usually a quick disconnect at the engine block drain spots and you could remove/poke those. I believe for your manifolds, though, you would just have to remove the hose to verify drainage and poke if you wanted to.

When memory serves pulling the hose leaves you with a 90 deg fitting so poking the manifold is pretty impossible wuthout removing it.

Funny thing is - the mercruiser manual does not call for things like this. It just calls pulling the plug at thw distributor , the vent plug at the tstat ,the two plugs at the waterpump and let the water drain for 15 minutes. Thats all.

I fully agree with you that doing it the official way may result in disaster , especially with an older engine which accumulatwd some sediment.

I do not know why mercruiser is going this way . My argumentation that i winterized due to their manual made them pay me a new manifold like described above