Mercruiser V-6 Winterizing

We live in a northern climate where anti-freeze is a must. Our old boat was a Mercruiser 3.0 liter 140 that required that you pull three brass plugs to drain, then pull the thermostat and fill the block and manifold with anti-freeze. Lately we have been hooking up a plastic tank and runnning 5 gal thru the engine just as its being fogged. Works well.

Our new boat is a 2007 Stingray with V-6. It has three blue plugs to drain the block, manifold, etc. The owners manual says to drain for the winter but mentions nothing about anti-freeze. We ran the usual 5 gal of pink stuff thru the tank again, but wonder if this really isn't necessary. Will the 3 blue plugs COMPLETELY drain all water?

Re: Mercruiser V-6 Winterizing

JimS123 said:

We live in a northern climate where anti-freeze is a must. Our old boat was a Mercruiser 3.0 liter 140 that required that you pull three brass plugs to drain, then pull the thermostat and fill the block and manifold with anti-freeze. Lately we have been hooking up a plastic tank and runnning 5 gal thru the engine just as its being fogged. Works well.

Our new boat is a 2007 Stingray with V-6. It has three blue plugs to drain the block, manifold, etc. The owners manual says to drain for the winter but mentions nothing about anti-freeze. We ran the usual 5 gal of pink stuff thru the tank again, but wonder if this really isn't necessary. Will the 3 blue plugs COMPLETELY drain all water?

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Pulling the plugs always did drain all the water out of the block and manifolds...AS LONG AS the drain holes weren't clogged with mud or rust. I always remove the drains and then ream out the holes with a piece of coat hanger to make sure they are clear. I have never removed the thermostat to fill the block with antifreeze. I just make sure the water is all drained out. This is on an '86 Mercruiser V-8. My 4.3 V-6 was the same way. The antifreeze is a little added insurance, but not really necessary in my opinion.

However, on a "V" motor (v-8 or v-6) there should be 4 plugs to remove, one on each side of the block and one in each manifold.

Re: Mercruiser V-6 Winterizing

Lately we have been hooking up a plastic tank and runnning 5 gal thru the engine

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From the......

So said:

thread

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JustJason said:

This comes up all the time, so I'll say this

DO NOT BUY OR USE ONE OF THOSE WINTERIZATION KITS LIKE THE ONE IN THE LINK BELOW!!!

http://www.westmarine.com/1/1/1305-e...st-marine.html

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If you don't go out and drain everything you dumped in there before it freezes you have a 50/50 shot at having a cracked block some spring time... Trust me

Re: Mercruiser V-6 Winterizing

We live in a northern climate where anti-freeze is a must. but wonder if this really isn't necessary. Will the 3 blue plugs COMPLETELY drain all water?

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Ayuh,... It's Never been a Must, nor a Necessaity...
A completely drained motor, can Not,+ will Never freeze,... Air just Don't Freeze...

As for your 3 blue plugs,... That might be the intended Design,...
But I'd Never trust it...
My 4.3l Merc has 2 block drains, 2 manifold drains, a P/S drain,+ I pull the Big hose off the circulating pump....
Like SuperNova says,... Ya gotta Dig the Crap out of the drains to be Sure....

Re: Mercruiser V-6 Winterizing

JustJason said:

From the......





If you don't go out and drain everything you dumped in there before it freezes you have a 50/50 shot at having a cracked block some spring time... Trust me

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What I dumped in with the West Marine Kit was straight anti-freeze. I've been using this kit for 6 or 7 years now. My local marina uses the same procedure. From the quote above, the person just gave an opinion, but didn't explain why its a bad idea.

For the 20 years previous to buying the 5 gal kit, I pulled the plugs, drained the water, then pulled the thermostat and manually poured in anti-freeze. A cumbersome procedure at best. The block in my 3.0 liter holds only about 2 or 3 gallons of water. So, wouldn't the 5 gallons of anti-freeze plug flow the system out?

Re: Mercruiser V-6 Winterizing

So, wouldn't the 5 gallons of anti-freeze plug flow the system out?

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Ayuh,... Only as long as the T-Stat stays open,...
Otherwise it by-passes through the exhaust manifold....

Re: Mercruiser V-6 Winterizing

Bond-o said:

Ayuh,... Only as long as the T-Stat stays open,...
Otherwise it by-passes through the exhaust manifold....

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We run the engine to temperature on the garden hose, then let it run a few minutes more to be sure all is hot. City water probably runs 50 degrees this time of year. IMMEDIATELY switch to the tank of anti-freeze that is at ambient temp. (so no temp shock to the TS)

Sound like an acceptable procedure?

Re: Mercruiser V-6 Winterizing

Bond-o said:

My 4.3l Merc has 2 block drains, 2 manifold drains

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So I have to pull the exhaust manifolds to pull the plugs and drain the water too? I cant find new ones on Iboats??

Re: Mercruiser V-6 Winterizing

Sound like an acceptable procedure?

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Nope,... Not to me,... You're still at 50/ 50 odds...

WAVENBYE2,... Your post makes No sense to me... The only thing Pulled are the Drain Plugs...

Re: Mercruiser V-6 Winterizing

Guys...the key to keeping your engine and manifolds from cracking is.....get ALL the water out of them. If, AFTER ALL THE WATER IS DRAINED, you want to add some antifreeze...then go for it. Attempting to flush the water out of the engine and manifolds with a antifreeze mixture is risky at best.

By the way, Bondo, I do the same thing with the big hose from the circulating pump. I also will usually pour a little antifreeze down the intake hose to protect the power steering cooler in case some water is stuck in that loop....I don't have a drain for that like you do. I pour it in until a little comes out of the outdrive pickups.

Re: Mercruiser V-6 Winterizing

JimS123 said:

We run the engine to temperature on the garden hose, then let it run a few minutes more to be sure all is hot. City water probably runs 50 degrees this time of year. IMMEDIATELY switch to the tank of anti-freeze that is at ambient temp. (so no temp shock to the TS)

Sound like an acceptable procedure?

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It's still a gamble...if you don't believe it....then drain some of what's in the engine into a paper cup...put it in the freezer and see what happens...or test it with a hydrometer that is made for propylene glycol (the company that makes Sierra antifreeze sells em)...
The issue is that the way most raw water cooled systems are set up...the af that your drive sucks up will come in the raw water intake hose..to the thermostat housing...then go into the manifolds and risers...but if your thermo is not all the way open...the block/heads will still have mostly water in them...that water will not circulate out...till the the thermo opens...and lets it out....so if you want to use AF for corrosion protection...drain and back fill....

Keep in mind...even if marinas do this suck the AF up the drive method...well not one manufacturer of raw water cooled sterndrives...ever recommended that in their manuals...all they ever recommended was to drain the water...then back fill through the hoses...for additional protection...so they are taking your money...and not doing it the way the engineers who designed the engine...said it SHOULD be done...

The suck the AF up the drive method can work fine on an engine with CLOSED COOLING (HEAT EXCHANGER+ ANTIFREEZE IN THE BLOCK AND HEADS...AND ALSO THE MANIFOLDS ON A FULL SYSTEM) ...NOT ON A RAW WATER COOLED ENGINE....

Re: Mercruiser V-6 Winterizing

By the way, Bondo, I do the same thing with the big hose from the circulating pump. I also will usually pour a little antifreeze down the intake hose to protect the power steering cooler in case some water is stuck in that loop....I don't have a drain for that like you do. I pour it in until a little comes out of the outdrive pickups.

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Ayuh,... 1 of the 1/2 dozen barges I winterize, I can't get to the P/S cooler,...
It's a little Slickcraft 195 that we pulled the 120hp/ mod.1 outa,+ dropped in a 350MPI/ Alpha 1, Gen.II...
On that 1, I backfill the line from the outdrive with Antifreeze...
Other than That,... Every boat I know of, or have to deal with are stored Dry...

Re: Mercruiser V-6 Winterizing

All this talk about the suck up method had me worried. I had winterized both the 3.0 and 4.3 before I posted the question. So today I bought a tester and drained both engines.

Both blocks and all 3 manifolds had 100% anti-freeze in them. Good thing I saved the empty jugs since I was able to save a few gallons for next year.