Cracked Block & Freeze Plugs on '96 Merc V6 I/O

[jackandh2o]

Newbie here and need help. Surprise freeze here in Arizona a while back and wasn't thinking about the boat but rather the RV. While getting it summer ready yesterday when all was done and hooked up the water to start it, the freeze plug on the front of the motor blew out.
Where do I go from here and please be nice. hehe

 

[Haut Medoc]

Re: Freeze Plugs on '96 Merc V6 I/O

Re: Freeze Plugs on '96 Merc V6 I/O

Welcome to iboats.....
Well, hopefully you haven't cracked your block &/or manifolds.......
I'm assuming that this is a raw water, not closed system.....
You could do alot of testing, but I would probably put the plug back in, start the engine on muffs & see if you get water in your oil.....
Or you get a visible rise on the dipstick
So note the oil level before starting the engine....
If it is cracked, it should not take long......
Then I would pull the plugs & see if you have any water in the cylinders.......
If it runs poorly, or will not crank, that would be a sign of water in the cylinders.....
Water in oil = Cracked block.......:'(
Water in cylinders = cracked or porous riser or exhaust manifold...
Good Luck!........

 

[flashback]

Re: Freeze Plugs on '96 Merc V6 I/O

Re: Freeze Plugs on '96 Merc V6 I/O

welcome Jack, Those core plugs don't just blow out. Ice in the block expanded and pushed the plug most of the way out.. Like Haut said, install a new plug and give it a try.. also take some time and visually inspect the engine and manifolds for cracks.. and check the other core plugs... if you come out of this with only replacing a core plug or two, consider yourself a very lucky person......

 

[Bondo]

Re: Freeze Plugs on '96 Merc V6 I/O

Re: Freeze Plugs on '96 Merc V6 I/O

Ayuh,........

1st thing to do is put the Coreplugs back in,+ Roll the Dice.............

Follow Haut's guidelines,+ Let Us know what Happens........

 

[jackandh2o]

Re: Freeze Plugs on '96 Merc V6 I/O

Re: Freeze Plugs on '96 Merc V6 I/O

Replaced soft plug with no problem. Started engine and have a crack in the head that is dripping water but oil appears to be ok.

Any suggestions ???

Thanks
Ray

 

[jackandh2o]

Re: Freeze Plugs on '96 Merc V6 I/O

Re: Freeze Plugs on '96 Merc V6 I/O

Correction, crack is in the block where it meets the head

 

[Haut Medoc]

Re: Freeze Plugs on '96 Merc V6 I/O

Re: Freeze Plugs on '96 Merc V6 I/O

If the crack is accessible, I would grind it clean & fill it with JB weld, and after it cured, run the engine again for an while (1/2 hour) & look at the oil & stick again.....
If you are very lucky, & that is the only crack, then I would still replace the head......
Sometimes those JB welds can last a long time, but I would replace the head........IMHO.....

 

[Haut Medoc]

Re: Freeze Plugs on '96 Merc V6 I/O

Re: Freeze Plugs on '96 Merc V6 I/O

Then I would do the same with the block, except I would run it till it dropped, with the JB weld repair....
They can last a long time in fresh water.....
But if you get water in your oil after an extended run, your block must be replaced......
I would still check for water in the cylinders anyway.....

 

[Gary H NC]

Re: Freeze Plugs on '96 Merc V6 I/O

Re: Freeze Plugs on '96 Merc V6 I/O

sounds like time for a new block.I have heard of people grinding around the crack and doing a repair.
If it was me the heads would come off next..there are probably more cracks you will see with the heads off...
What a bummer...:%

 

[DHPMARINE]

Re: Freeze Plugs on '96 Merc V6 I/O

Re: Freeze Plugs on '96 Merc V6 I/O

I wouldn't do much before a good hard lake test.This brings things up to max temp (and expands things).It also puts max water pressure thru the whole system.

If nothing else happens except that one crack,grind it and Marine Tex it.And forget it.JB weld is also good,but use slow cure in either case.

Guess you have learned there are no 'freeze' plugs.


DHP

 

[jackandh2o]

Re: Freeze Plugs on '96 Merc V6 I/O

Re: Freeze Plugs on '96 Merc V6 I/O

Thanks to all for your feedback. Along with the Vortec
the other one with the Ford V6 has water in the oil.
Two boats, two cracked blocks. I never dreamed that this
could happen in western Arizona. I also thought that when the boats came out of the water all the water left the block.
Both boats belond to my son in laws and they store them with us in the winter so it, is just a commute from Ca. in the summer time to Lake Mohave about 20 miles from us.

We will certainly WINTERIZE next year.

Again thanks to all

Ray

 

[Bondo]

Re: Cracked Block & Freeze Plugs on '96 Merc V6 I/O

the other one with the Ford V6 has water in the oil.

Hmmmmmmm,............

I've Never seen, or heard of a Ford V6 in a Boat.........

 

[jackandh2o]

Re: Cracked Block & Freeze Plugs on '96 Merc V6 I/O

My mistake, the cocktail flag was already up. It is an OMC and they thought most engines were Chevy or Ford. It is a 3.9 V6

Ray

 

[Haut Medoc]

Re: Cracked Block & Freeze Plugs on '96 Merc V6 I/O

Hmmmm.......3.9 V6?.....

 

[Bondo]

Re: Cracked Block & Freeze Plugs on '96 Merc V6 I/O

Sounds like it Might be 1 of those old Buicks that OMC used.......

 

[Don S]

Re: Cracked Block & Freeze Plugs on '96 Merc V6 I/O

No such thing as a 3.9 either, want to try again? ? ? :/

 

[Zim]

Re: Cracked Block & Freeze Plugs on '96 Merc V6 I/O

No such thing as a 3.9 either, want to try again? ? ? :/

A ford 3.9L does exist... except it resides in the v6 mustangs lol

 

[jackandh2o]

Re: Cracked Block & Freeze Plugs on '96 Merc V6 I/O

It is a rather old Galaxy, 1985 maybe someone did an engine swap prior to buying it

Ray

 

[Don S]

Re: Cracked Block & Freeze Plugs on '96 Merc V6 I/O

No such thing as a 3.9 either, want to try again? ? ? :/

A ford 3.9L does exist... except it resides in the v6 mustangs lol

I guess I should have said a MARINE 3.9 engine. You also can't just go out and stick any ole engine in a boat. You need things like a water cooled exhaust system, marine certified electrical system a way to hook it to the drive and all that neat stuff.

As Bondo mentioned, OMC used the Buick engine with the stringer drives. It was a 3.8L V6 engine

 

[Zim]

Re: Cracked Block & Freeze Plugs on '96 Merc V6 I/O

No such thing as a 3.9 either, want to try again? ? ? :/

A ford 3.9L does exist... except it resides in the v6 mustangs lol

I guess I should have said a MARINE 3.9 engine. You also can't just go out and stick any ole engine in a boat. You need things like a water cooled exhaust system, marine certified electrical system a way to hook it to the drive and all that neat stuff.

As Bondo mentioned, OMC used the Buick engine with the stringer drives. It was a 3.8L V6 engine

I was just givin' you a hard time