block full , water in cyls, intake valley full !!!!!

[75omc302]

omc 302 1975motor, Freeze plugs popped, pulled motor up and replaced them. No cracks on outside of the block. cleaned out the fuel system, replaced coil and set points . put in the water primed it , fired up nicely. Spent about 10 minutes on the water and the motor loaded up and died. No hydralic lock happened. towed in and trailered . Checked oil and found vast amounts of water in oil. Figured the intake or head gaskets let go. pulled intake and valley was full of milk, valve train same, pulled heads, one side very wet with milk. Block is full of milk too !!!!!! compression check showed low or no comp in 1 thru 3, but 5 thru 8 was 120 psi or better. Now what ? cant find cause, or am not sure. dont want to do heads and intake to find out in the water it is in somethingelse !! HELP!!!!! @#*&@ cold wether !:facepalm:

 

[Maclin]

Re: block full , water in cyls, intake valley full !!!!!

Just an opinion, but the cooling passages inside the block are cracked.

The freeze plugs are not really that at all, they are casting core plugs and not a fuse for freeezing. The passages are narrow on the inside of the block and if the freeze was hard enough to pop out more than one core plug on the outside then the inside passages did not have a chance.

 

[CoffeeHound]

Re: block full , water in cyls, intake valley full !!!!!

Howdy OP welcome to Iboats >
SD Hey ? Ok,, you should know boats have motors just like cars and trucks and require winterizing .
Bet you also know what happens when you dont.
Dont feel lonesome because it also happens from time to time in Mi. also and that is part of the reason
that i am in Tx.-- Hate Snow !!
I suggest you get a short block and start building a new power plant for your boat after you find all the cracks
in the old one !!

 

[Don S]

Re: block full , water in cyls, intake valley full !!!!!

You have at minimum a cracked block. With water in the cylinders too, probably cracked heads as well. Clean the milky mess off the lifter valley and you will likely be able to see the cracks. The chance of it being a head gasket are about the same as me winning the lottery. And I don't play the lottery, so guess where that puts the chances.