Oh No! Missed water drain plug

Stupid rookie mistake. I wanted to take my 2006 Tahoe Q6 out on the lake this weekend so yesterday I began to summerize the boat. This boat has the 4.3L Mercruiser. I put the muffs on and started the engine. The engine turned over and after a moment of ruff idle, she smoothed out and began to purr. I turn around and there's 6 inches of water in the bilge. Oh Crap!!! I shut everything down and found water pouring out of a "freeze plug" hole on the side of the block. I felt physically sick. Apparantly I missed the water drain plug on the rear/right during winterization. I checked the oil dipstick but didn't notice any milky color. Took it to the Mercruiser mechanic who seemed more hopeful than me. He said he has seen three cases this year of freeze plugs that had to be replaced but the engine blocks weren't damaged. Nothing to do now but sit and wait and hope the block isn't cracked.

Re: Oh No! Missed water drain plug

So, if it was coming out a plug hole, that is a good thing. Sounds like, on the surface, that you need a new plug.

Re: Oh No! Missed water drain plug

Ayuh,... At this point, all that can be done is replace the Coreplug,+ Try it...

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The mechanic can't get to it until Friday. Until then I'll take all the support and warm fuzzy comments I can get as I still feel sick about it. Any serious/expensive damage = no boating season for me BTW, My manual is not handy at the moment, does anyone know if there are three or four drain plugs on the 2006 Mercruiser 4.3L V6 (points ignition if that makes a difference)?

Re: Oh No! Missed water drain plug

does anyone know if there are three or four drain plugs on the 2006 Mercruiser 4.3L V6 (points ignition if that makes a difference)?

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Ayuh,... There are Atleast 4,... Maybe more...
And,...
No way in 'ell a 2006 has Points igntion, unless it's been cobbed in...

Re: Oh No! Missed water drain plug

There should be 5 plugs.

I have a 2006 4.3L Carb with the TKS turn Key start.

There are two on the underside of the block.

Two on the underside of the manifolds

One in the front at the water pump.

Should be all blue...they kind of look like wing nuts.

Hope this helps, good luck keep us posted

Re: Oh No! Missed water drain plug

Bond-o said:

Ayuh,... There are Atleast 4,... Maybe more...
And,...
No way in 'ell a 2006 has Points igntion, unless it's been cobbed in...

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There again, I could be misspeaking. It is carbureted and has a distributor. The boat is an 06 and the engine is new but may have been manufactured prior to 06. But I know I only removed three drain plugs and didn't see the one on the right/rear so that answers that. Thanks for the reply.

Re: Oh No! Missed water drain plug

That sucks...and you have to wait to find out your fate. I'm sure it'll be alright...that's what freeze plugs are for.

BTW, I appreciate all of you who do your own work on your rigs but this is the very reason I prefer to pay someone. The relatively small charge to winterize compared to the agony of finding out I might have screwed it up.

Re: Oh No! Missed water drain plug

Why wait till Friday? Go get the boat, buy a plug from the mechanic, throw it in and fire her up.

You already said the engine was purring with the plug out. That's a damn good sign.

Re: Oh No! Missed water drain plug

Its a flip of the coin. Heads you win, Tails you have a cracked block.

The blocks crack right along the sides, usually just above the core plugs.
But they also crack in the lifter valley.

Being as how the cooling system didn't have any pressure in it. (because of the missing core plug) water may not have even made its way up to the lifter valley/intake/head area.

At this point I would just throw a rubber bung core plug temp patch + run the snot out of the boat, under load, in the water. When you come back to the dock shut her down and drain a little bit of the oil. (or take the filter off and dump it in a plastic container) and watch to see if there is water. If you changed your oil last fall and stored it, it will/should still look new. When it looks new it's harder to tell if there is water in it. So don't trust the eyes on the dipstick, take a sample.

Good luck

Re: Oh No! Missed water drain plug

Bubba1235 said:

Hindsight being perfect and all that... I know that if everything is drained properly there is no need but,,, lots of folks don't do a good job of winterizing their engiens and is the reason I tell DIY types to close the drains once the water is out and pour a gallon of anti-freeze into the the engine. To my thinking, it's very cheap insurance.

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I do the same wire out the plug holes and use gallons of a/f after the water has been drained.

Re: Oh No! Missed water drain plug

I'm sure it'll be alright...that's what freeze plugs are for.

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Nope,... No it Ain't...

There's No such thing as a Freeze plug,...

They're Core plugs,...
They're for releasing the core sand out of the casting...

Re: Oh No! Missed water drain plug

As has been noted many times...A properly drained engine should never have freeze damage...to all beginng self winterizers...MAKE SURE YOU KNOW WHERE ALL THE DRAINS ARE...WHEN YOU REMOVE ONE...MAKE SURE WATER COMES OUT...IF NOT ROD OUT THE HOLE TILL IT DOES...KEEP THE ENGINE LEVEL DURING DRAINING...

Re: Oh No! Missed water drain plug

As has been noted many times...A properly drained engine should never have freeze damage...to all beginng self winterizers...MAKE SURE YOU KNOW WHERE ALL THE DRAINS ARE...WHEN YOU REMOVE ONE...MAKE SURE WATER COMES OUT...IF NOT ROD OUT THE HOLE TILL IT DOES...KEEP THE ENGINE LEVEL DURING DRAINING...Don't forget there are sometimes power steering coolers that need to be drained too...you need the OE Shop manual for YOUR engine....

I do it a little different in that I do add AF but in my opinion the only way to use AF is to manually drain first THEN add AF...

After draining the block and manifolds....
I also remove the big hose between the thermo housing and the raw water intake hose at the thermo housing...both will hold water and need to be drained...

Finally I reinstall the lower end of the big hose on the circulating pump...and with the block drains open...pour in the top end of that hose... -100 marine antifreeze...you can see it push out the remaining water...then I put some grease on the drain plug threads...re-install the plugs......and fill the engine with -100 till the AF appears at the thermo housing...then re-connect the big hose at the therm housing. I do the same with the manifolds...fill through the hoses till it pushes out the water left in em...grease and replace the drain plugs...then fill with AF till it runs out the exhaust...lastly...I fill the raw water intake hose with AF after I drained the water out of it...till AF comes out the water intakes on the drive...if you do it this way...you KNOW the water's out...and so's the AIR...which in itself contributes to corrosion (rust = iron oxide good ole Fe O2)...a basic fact of chemistry that many do not understand...its not water that causes corrosion per se but the OXYGEN in the water that causes it...that's why bare cast iron or steel left in the air..will rust...even if it's not being rained on...

Re: Oh No! Missed water drain plug

Took it to the Mercruiser mechanic who seemed more hopeful than me. He said he has seen three cases this year of freeze plugs that had to be replaced but the engine blocks weren't damaged. Nothing to do now but sit and wait and hope the block isn't cracked. http://forums.iboats.com/newreply.php?do=newreply&p=2562212

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http://forums.iboats.com/newreply.php?do=newreply&p=2562212

No wonder they're called "Freeze Plugs"

I had the same thing happen to my 454. sometimes there's a tiny amount of water left in the block after draining.......Just enough to be up to a core plug.

When the water partially freezes, it may push out a core plug that was already almost loose enough fall out.

When I got my 454, I already had the engine on a stand. I removed the rest of the "freeze" plugs and inspected the block inside and out (I had the intake manifold off too)

The little bit of water left was evidently not enough to crack my block...... I installed closed cooling on mine.....it'll never happen again.......

You may be lucky this time.............

Re: Oh No! Missed water drain plug

I pour about 3-4 gallons of antifreeze through the circulator pump hoses untill it runs out the exhaust after draining all the seacocks on the engine/risers. As mentioned even a little bit of water can be catastrophic. Put a new core plug in and give er' a shot. At this point you got nothin to lose.

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and thats why the correct procedure, after you thinks its drained, is to supply an A/F mix good for at least 50* below to the water intake and blow at least 5 gallons through the system.
that way all the nooks,crannys,oil coolers and riser pockets get protected not only from freezing but from corrosion damage, espesially in salt water areas.
as a business owner and a contract tech if I mess up I buy the block.
I have not bought a block in over 30 years.

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You should never leave a motor empty all winter. Fresh and especially salt water will cause corrosion if left to the air.Any GOOD anti-freeze mix will stop this. The red stuff sold at any marine/rv dealer(make sure it's for the motor)will work.Keep it in the manifolds too.
Most places it's ILLEGAL to use real auto antifreeze.Most people go to the water and start it up dumping all that poison in the water.
Very expensive ticket.I believe it's a felony.J

Re: Oh No! Missed water drain plug

Mechanic just called. He looked over the block with a remote camera and didn't observe anything abnormal. The one plug that is out is an easy fix and I can do that. He did say that the plug located by the starter looks like it may have moved and needs to be replaced. This plug would require an engine pull $750.00. I'm thinking for that price I'm going to get the boat and try my best to become a spider monkey, get down there and try to change it out myself. Worst case, I take it back and pay the $750.

Any advice on the plug that looks like it may have moved? Should I replace the one that's out, run the boat and see if it is a problem first, or just replace it?

Re: Oh No! Missed water drain plug

How far can you row if it falls out?