1989 3.0 Merc cracked Block

[Definitive]

I picked this boat up for very little so i dont mind putting in a little work, im looking for some opinions from those of you who have repaired cracked iron blocks in the past.

Any help you all can offer will be much appreciated

the details.

I purchased with the information that water was leaking from engine up under or near the intake at or about center from front to back while running, and that the temp gauge ran normal and there was no sign of water in the oil.

I brought it home and after about and hour of removing parts i found the crack.

The size and shape of this crack concerns me, its very high on the block running lengthwise yet vertically entering the water chamber, I removed the thermostat and ran the garden hose at low pressure which was enough to jet water out of crack in an upward arching motion.

I can understand the method of repairing the block but im thinking the out side might not be the only problem, wouldn't the inside be damaged as well?
This crack is located about 10" above the "freeze plugs" yet there appears to be some rust stains from a seem line in the paint about 2" below the same plugs causing me to think there may be 2 cracks running parallel with each other
So what if I made the repair, whats the chances that the giant slab of iron could pop off while in use?

being the sale is final and a refund/buyback is not an option, what would be suggested that I do?

Thanks in advance

 

[cedarjunki]

Re: 1989 3.0 Merc cracked Block

I picked this boat up for very little so i dont mind putting in a little work, im looking for some opinions from those of you who have repaired cracked iron blocks in the past.

Any help you all can offer will be much appreciated

the details.

I purchased with the information that water was leaking from engine up under or near the intake at or about center from front to back while running, and that the temp gauge ran normal and there was no sign of water in the oil.

I brought it home and after about and hour of removing parts i found the crack.

The size and shape of this crack concerns me, its very high on the block running lengthwise yet vertically entering the water chamber, I removed the thermostat and ran the garden hose at low pressure which was enough to jet water out of crack in an upward arching motion.

I can understand the method of repairing the block but im thinking the out side might not be the only problem, wouldn't the inside be damaged as well?
This crack is located about 10" above the "freeze plugs" yet there appears to be some rust stains from a seem line in the paint about 2" below the same plugs causing me to think there may be 2 cracks running parallel with each other
So what if I made the repair, whats the chances that the giant slab of iron could pop off while in use?

being the sale is final and a refund/buyback is not an option, what would be suggested that I do?

Thanks in advance

if the block is cracked like that im guessing the head and or manifold might be cracked too......might be better off looking for a junk boat with a motor

 

[JustJason]

Re: 1989 3.0 Merc cracked Block

You have freeze damage from an unwiterized boat. To bad you can't take the boat back. You will have to check the intake manifold and risers also for freeze damage.

The block is pretty much junk. I say pretty much because although you can expoxy over the crack with jb weld or your favorite cold weld, and it will work for a while, the repair will eventually fail.

2.5's, 3.0's, and inline 6's always crack right there up under the manifold. Those motors tend not to crack internally though.

 

[chenta]

Re: 1989 3.0 Merc cracked Block

I had a 1968 merc. 160 that had the same problem. The person that I bought it from said that it was just a leaking gasket. I ended up taking it to a repair shop that delt with river boats and had it welded. It had cracked between the number 2 and 3 cylinder and was 2 - 3 inches long. It cost me about $300 for this man to weld it up and has not to date leaked anything more. I made sure to have the boat winterized so that it didn't happen again.

 

[Definitive]

Re: 1989 3.0 Merc cracked Block

WOW thank you guys for your replies.

Im a little disappointed in what i found, and I understand this was not winterized at all and spent 2 winters this way

Now i am trying to figure out how to turn the crank to see if it will spin without obstruction (Literally running outside wrenching, inside reading lol ) i have the crack exposed and water pump removed, i am confident in considering the JB weld repair method, although id like to make sure she spins prior to instituting the repair, id hate to waist my time on it.

Now does anybody have a structured list of instructions of how to perform the installation?

ie. tools, agents, etc

thanks again