Mercruiser V-6 4.3 alpha one freeze plug/ core plug locarions

[chrisv]

Hello,

When I tried starting my boat after a prolonged storage I found water leaking to the bilge and two freeze plugs fallen in the bilge. I think some people refer to them as core plugs too. I want to try to put them back them while the engine is in place (i.e., without removing the engine from the boat). I was actually able to replace one as I found the open hole it fell out of. It was on the starboard side.

But for the life of me I cannot find where the other one fell out of. Does anyone have a diagram of the freeze/core plugs? I would like to see if I can pop it back in or I need to to lift the engine.

By the way, I know that popped freeze plugs are usually a sign of a cracked case but I checked the oil and there is no milkiness. So cross fingers it seems alright.

 

[achris]

Re: Mercruiser V-6 4.3 alpha one freeze plug/ core plug locarions

Hi Chris,

Welcome to iBoats...

Core plugs are sometimes referred to (incorrectly) as freeze plugs.... There are usually 3 core plugs along each side of the engine....

The reason they popped out is usually because there was water still in the block during winter, which froze and expanded. If you don't have a crack in the block somewhere consider yourself very lucky....

When you winterized it, are you one of the 'fill it with anti-freeze' brigade?

Chris.......

 

[Bondo]

Re: Mercruiser V-6 4.3 alpha one freeze plug/ core plug locarions

But for the life of me I cannot find where the other one fell out of.

Ayuh,.... Welcome Aboard,... look directly behind the motor mount...

 

[chrisv]

Re: Mercruiser V-6 4.3 alpha one freeze plug/ core plug locarions

Hi thanks for the responses. The first plug that popped out was in fact behind the motor-mount. I put that one back in. However I cannot find where the second one popped out of. Can you guys give me other locations where these plugs may reside?

And no, I did not use antifreeze. I fell for the typo in the manuals. I read there are three blue drain plugs I had to drain, and I drained three and left it at that. Turns out there were two more.

 

[Struc]

Re: Mercruiser V-6 4.3 alpha one freeze plug/ core plug locarions

By the way, I know that popped freeze plugs are usually a sign of a cracked case but I checked the oil and there is no milkiness. So cross fingers it seems alright.

My block was cracked in two places and ran fine and had no milky oil, so by no means is that an indicator that your engine is fine. Yes, usually if a core plug is pushed out, that means it is likely the block is cracked.