New to winterizing..is it possible to fill cylinders with antifreeze?

Coldsteel5

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Hey there, new to the forums and new to owning an i/o boat. Ive owned waverunners for years, but recently purchased a 96 cobalt 190 in great condition. It has a 4.3 lxh gen+, alpha one outdrive, had it out on the lake several times. I will be storing the boat in a non climate controlled shed during the off season in IL. I removed the 2 block plugs and 2 manifold plugs to drain the water in the block and manifolds and reinstalled the plugs to start pouring antiffreeze through the hoses at the t-stat housing. My concern is when pouring antifreeze in the manifold hoses that i poured to much and backfilled the manifolds and possibly got coolant into the cylinders. Is this possible? I dumped a little under 1/4 gallon into each manifold hose then removed the plugs to drain out the bottom of the manifolds.
 

alldodge

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My concern is when pouring antifreeze in the manifold hoses that i poured to much and backfilled the manifolds and possibly got coolant into the cylinders. Is this possible?

No, not possible. The more its filled the more pours out the exhaust

Being a 1996 its probably a carb, if its EFI then don't forget the cool fuel module
 

Coldsteel5

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Thanks for the reply. Forgive me if this is not posted in the right location. Is the cooling water separate from the exhaust gas in the manifolds via water jackets and the water & exhaust meet past the riser portion? It has the one piece exhaust manifolds. Just want to be sure I dont have water in the cylinders when it comes time wake it up in the spring. Also, I was only able to locate 4 drain plugs, Ive been told these engines have 5. I was not able to locate one on the front of the engine. Am i missing something? you are correct it has the 4bbl carb.
 

Lou C

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While you found the 4 plugs and drained those, you also have to remove the bottom end of the large hose that connects the circulating pump to the thermostat housing, that pump holds a lot of water and it won't drain unless you disconnect that hose. The 5th plug they are referring to is on the front edge of the intake manifold, it may be hiding behind one of the cooling hoses, its probably a square plug. This was a change from the older pre Vortec engines like mine to the Vortec, on the Vortec this area can hold water and can cause cracks.
As long as your exhaust manifolds don't leak internally you can't get get AF in the cyls from filling them, it will run out the exhaust reliefs under the transom mount. The exhaust gas and water passages are separate they only combine at the outlet of the elbow, which is under the rubber exhaust hose, but it won't back up into the engine that way. The only way that could happen is if the manifold or elbow has a crack or rusted through area, or if the gasket between the manifold & the elbow leaks (two piece wet joint style).
BTW, I'd think about converting the one piece manifolds to the better 2 piece style, casting problems with them have resulted in thin wall thickness and cracking and that can ruin engines. THAT problem can for sure put water into a cyl. Barr Marine makes a nice conversion kit. Not cheap but if you are keeping the boat, I'd get rid of those. Merc discontinued them for that reason, could not get consistent wall thickness using the casting method they had. Bad exhaust manifolds are a top cause of inboard engine failures. Here in salt water we are used to replacing them, every 5-7 years due to corrosion.

Here's a pic of that 5th plug.
Also if you have a P/S cooler behind or next to the engine, I'd put the outdrive down, then disconnect your raw water intake hose at the thermostat housing. Hold it down to drain it, then hold it up and fill the hose with -100 marine AF till it runs out the outdrive water itakes. That will push water out of the PS cooler and hoses that go through the transom mount.
 

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alldodge

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The water exits before the exhaust.They meet further down

There may be a drain plug on the power steering cooler but it should be behind and on top the rear of the motor. If the cooler is there, then it doesn't need to be drained because gravity drains it.

The large hose on the recirculating water pump may have a drain. If it doesn't then remove the lower section of the hose and then reinstall.

Exhaust.jpg
 

racerone

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Had a call from local sailing friend some time ago.------Said he was winterizing a 3 cylinder VOLVE diesel.----Had the bucket of antifreeze in the cockpit.----Ended up with coolant in the cylinders and a locked up motor.------So I helped him out and got motor running.----Oil changed and motor happy.-----But get this.-----He made same mistake again next day.------So yes it is possible to make mistakes with simple winterizing projects.
 

alldodge

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Had a call from local sailing friend some time ago.------Said he was winterizing a 3 cylinder VOLVE diesel.----Had the bucket of antifreeze in the cockpit.----Ended up with coolant in the cylinders and a locked up motor.------So I helped him out and got motor running.----Oil changed and motor happy.-----But get this.-----He made same mistake again next day.------So yes it is possible to make mistakes with simple winterizing projects.

How?
What 3 cyl diesel?
 

alldodge

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Should add, IF the exhaust has not issues with cracks, bad gaskets, prior water ingestion, there is no way pouring water/AF from the bottom hose, it will get into the cylinders.

Also that said, AF is not necessary once water has been drained
 

Bondo

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Ayuh,..... I agree with AD,.... Yer bud probably has an exhaust Problem,.....
 

racerone

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Nope-----Error on part of the owner filled cylinders with with antifreeze/ water.
 

racerone

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Sailboat engines are often below the waterline.----They use a " waterlift " muffler.-----If you do not understand how this works you can fill cylinders with coolant from a bucket that is above the motor.
 

alldodge

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Sailboat engines are often below the waterline.----They use a " waterlift " muffler.-----If you do not understand how this works you can fill cylinders with coolant from a bucket that is above the motor.
ok, all good
And good thing this is not the same design/type
 

racerone

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Fact is , that mistakes are made working on boats.---Even simple jobs on boats are messed up by a novice.
 

Coldsteel5

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Thanks for all the helpful information and advice, I appreciate your guys response.
The 5th plug they are referring to is on the front edge of the intake manifold, it may be hiding behind one of the cooling hoses, its probably a square plug.
I found this square plug in the front of the intake, along with some others on the top of the intake. My question is, is it necessary to remove this plug if ive already poured antifreeze into the hose going to circulating pump enough that it filled the block and was coming out of the t-stat housing?
Also if you have a P/S cooler behind or next to the engine, I'd put the outdrive down, then disconnect your raw water intake hose at the thermostat housing. Hold it down to drain it, then hold it up and fill the hose with -100 marine AF till it runs out the outdrive water itakes. That will push water out of the PS cooler and hoses that go through the transom mount.
I have the power steering cooler behind the engine, but didnt see or find any drain plugs on it. Not sure how one would even get to it. I poured a gallon of antifreeze down the hose you mentioned till it started coming out the outdrive, hopefully good there.
 
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