water gushing from engine-Help!!!

[LSV04]

I put the boat in today to run it and check for leaks-If you were facing the back of the boat towards the lower left half of the engine I find this loose cap or plug like the size of a golf ball that seemed to fill this empty hole-no threads-like a little dish,brass or gold in color and the outer part is black maybe because this was the end in the engine holding in the water-anyway when the engine is on water starts pouring out of this hole-thank god we didnt just go riding without checking everything-this was a good lesson to check everything while on the trailer.
The opening is blocked by an engine mount bracket. How else can I get to it ?. I think this might of been leaking for a while and now it finally popped out completely-it seems like if I could get to it I could easily put it back. Anyone have this happen??? or know what it is-I am going to the Marina tommorow . Is it a flushing plug? help!!!!

[pickle311]

sounds like a freeze plug that goes in the block, but I thought those were only in ford engines, not Chevys. Maybe it's something that was added for marine.

[Engine Nut]

I put the boat in today to run it and check for leaks-If you were facing the back of the boat towards the lower left half of the engine I find this loose cap or plug like the size of a golf ball that seemed to fill this empty hole-no threads-like a little dish,brass or gold in color and the outer part is black maybe because this was the end in the engine holding in the water-anyway when the engine is on water starts pouring out of this hole-thank god we didnt just go riding without checking everything-this was a good lesson to check everything while on the trailer.
The opening is blocked by an engine mount bracket. How else can I get to it ?. I think this might of been leaking for a while and now it finally popped out completely-it seems like if I could get to it I could easily put it back. Anyone have this happen??? or know what it is-I am going to the Marina tommorow . Is it a flushing plug? help!!!!

That plug is a core plug and. It is one of 4, two on each side of the engine. Their purpose is to plug the holes in the side of the block where the core sand material is removed from the block at the foundry. These plugs are many times incorrectly called "freeeze plugs"and give people the idea that they are supposed to pop out of the engine if you forget to drain thewater from the block and the water freezes and expands ... WRONG!! I have seen many blocks freeze and crack with the core plugs intact. If yours popped out and the block isn't cracked, consider yourself very lucky.

At any rate, have your dealer reinstall the plug and run the engine to check for external leaks. Also after it has run for a while, check for water in the oil from an internal leak. If there is an internal leak, the oil will be "milky". If you have no internal or external leaks you should be OK.

Good Luck!

Engine Nut

[LSV04]

Thanks for all the info-at least now I know what I am getting into. Do they pop out due to the freeze. I had it fogged and thought they put anti freeze in. I didnt see water coming out anywhere else and I will check the oil now. I have major problems if something cracked. Thanks for your help.