Just pulled my 3.0 motor with cracked block

[Nickdogg]

Just got my motor out of my boat it has a crackd block. the crack is right below were the heads bolt down on the block. the mechanic told me the crack was probley all the way threw n water was getn in the cylinders or cylinder. When i pulld the heads off there was no crack on cylinders n no water leakn in there like it is the outside of block. Could it b cracked in the cylinder and i just cant see it. There is no water in the oil. Can anyone tell me anything about this. THANKS

 

[sam60]

Re: Just pulld my 3.0 motor with crackd bolck

Re: Just pulld my 3.0 motor with crackd bolck

I have the same issue. Mine's out and I'm tearing it down this weekend to look inside. Only way that I will know for sure.

After that, magnaflux and sleeving if it's not too destroyed.

Previous owner of mine thought that the light freezes that we get in southern Nevada couldn't hurt the block.

 

[HT32BSX115]

Re: Just pulld my 3.0 motor with crackd bolck

Re: Just pulld my 3.0 motor with crackd bolck

Previous owner of mine thought that the light freezes that we get in southern Nevada couldn't hurt the block.

Previous owner of mine (My brother!!), when it had the 460 inside, had it crack in Novato, California (NW of SF Bridge) He didn't think it could happen there either!!!

Could it b cracked in the cylinder and i just cant see it. There is no water in the oil. Can anyone tell me anything about this. THANKS

The 3.0L engine usually cracks on the outside on the left (port) side up under the manifold (where it's hard to see)

The block can be fixed but it has to go to a machine shop to get it done right.

http://www.usengine.us/mercruiser.html (Scroll down to the 3.0L engine)

 

[Nickdogg]

Re: Just pulld my 3.0 motor with crackd bolck

Re: Just pulld my 3.0 motor with crackd bolck

Thats right were it crackd,i have run the boats with the crack a few times. But now it idels rought n smokes(not oil smoke) n dont wamt to take gas. Could the crack b the problem???? The machanic said thats my problem,said sumn bout not enough crank comprestion,n gas might b gettn to my cylinders or valves.. Could this be the case????????

 

[Don S]

Re: Just pulld my 3.0 motor with crackd bolck

Re: Just pulld my 3.0 motor with crackd bolck

Have you checked the oil? Is it way over full and milky?

 

[Nickdogg]

Re: Just pulld my 3.0 motor with crackd bolck

Re: Just pulld my 3.0 motor with crackd bolck

There is no water in the oil. There is a lil gas in my oil tho.

 

[Howard Sterndrive]

Re: Just pulld my 3.0 motor with crackd bolck

Re: Just pulld my 3.0 motor with crackd bolck

There are dozens if not hundreds of 3.0's running around with a slathering of JB weld on the side.
The 3.0 is unique in that it likes to crack externally on the port side without cracking to the inside.
not many engines that forgiving of non-winterization

 

[Nickdogg]

Re: Just pulld my 3.0 motor with crackd bolck

Re: Just pulld my 3.0 motor with crackd bolck

Really, how can i tell if thats the problem? No water in oil. The only water was a little leak were the GB had crackd a lil, but very small leak.

 

[Bamaman1]

Re: Just pulld my 3.0 motor with crackd bolck

Re: Just pulld my 3.0 motor with crackd bolck

Worse comes to worse, Mercruiser sells short blocks for the 3.0.

I too had to replace such a engine when a head gasket gave way--pitting the metal between two cylinders. I had to wait for Mercury to cast a new short block--6 months. Come to find out, they seldom have a case where the engines just wear out. Mercury doesn't appear to always have every spare part in stock.

The vast majority of inboard outboard engine replacements are for freezing engines. Freezing issues are just a waste, as the block plugs to drain water from the engines are just so easy to get to. Winterizing a boat is a simple, short procedure that anyone could perform.

 

[Nickdogg]

Re: Just pulld my 3.0 motor with crackd bolck

Re: Just pulld my 3.0 motor with crackd bolck

I found a replacement GM engine. They siad i got to buy engine,then a 12 3/4 flywheel because it comes with a fourteen inche flywheel. And then buy a coupler. About 2500$ Just wanta make sure the one i got is to far gone before i make that purchuse..

 

[Nickdogg]

Re: Just pulld my 3.0 motor with crackd bolck

Re: Just pulld my 3.0 motor with crackd bolck

could water be getn to my heads or cylinders????

 

[Howard Sterndrive]

Re: Just pulld my 3.0 motor with crackd bolck

Re: Just pulld my 3.0 motor with crackd bolck

Really, how can i tell if thats the problem? No water in oil. The only water was a little leak were the GB had crackd a lil, but very small leak.

you answered your own question
I don't know what GB is though.

 

[Nickdogg]

Re: Just pulld my 3.0 motor with crackd bolck

Re: Just pulld my 3.0 motor with crackd bolck

GB weld, wouldnt it be water in oil if it was getn to my valves?????

 

[Howard Sterndrive]

Re: Just pulld my 3.0 motor with crackd bolck

Re: Just pulld my 3.0 motor with crackd bolck

you haven't done any diagnosis. Instead of playing spin the wheel of possible problems, do the pressure test suggested and do a compression test on the engine.

 

[Howard Sterndrive]

Re: Just pulld my 3.0 motor with crackd bolck

Re: Just pulld my 3.0 motor with crackd bolck

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