blown freeze plug

I

itteitj

New Member
Apr 19, 2009
4
Last fall I decided to let my friend winterize my engine as he said he does his own each year and never had a problem. I hesitated about letting him do it but decided to save the money. Well it looks like this is going to be the most expensive savings I ever had. I brought the boat to my house on the trailer to change the engine oil, filters, zincs and do a couple of other things. The boat is a 215 weekender with a 5.0 mpi seawater cooling. When I started the engine I noticed a lot of water coming out of the sump drain plug. I shut the engine down to see if it was a hose or an open drain plug. I finally restarted the engine and felt around the leaking area and found what appears to be a freeze plug leaking water. The plug is right behind the engine mount. Needless to say I am sick over this. I called my friend and he said it couldn't be and he came over to see for himself. He told me he was sorry and left. I was ready to kill him. I went in the house and read the winter storage instructions and realized we clearly did not do it correctly. I believed someone else before checking myself. He will never touch this boat again and I question his friendship. However, I need to get this repaired and need advice about what the repair entails plus costs to do it. The boat has less than 100 hours on it and is a great boat. :smt013:smt013:smt043:smt043:smt100 Any comments will be greatly appreciated and yes, I know I did a stupid thing.
 
Relax....
Things happen.

It actually happen to one of my old boats too.
The marina that did it installed a new freeze plug, I think it hammers in? and all was fine.
Just make sure theres no other engine block cracks. But that's why the plugs are in there. To hopefully prevent other damage.
 
if you can get to the freeze-out plug, its a relatively easy repair. Remove the old one and tap the new one into place. I would imagine getting to it will be the most difficult part of the process. And the 5.0 MPI is so easy to winterize, its almost scary that your friend didnt do it right: pull the 3 blue drain plugs on the engine, let the water drain out, fill a 5 gallon bucket with antifreeze and put it on the swim platform, use the "ear-muffs" on the outdrive, connect a hose to it, the other side in the bucket, and just start your engine. When the pink starts coming out of your outdrive exhaust, shut it off. Done. $15 is what it should cost to winterize the outdrive and the engine. :)

Hopefully the freezeout plug did its job and theres no damage to the block. Good luck!
 
The only other safety precaution is to pull the thermostat if running antifreeze through the block. Before - you assume the engine is shot - have you looked at the oil. Is it normal?
 
When water freezes in a GM small block one of the most vulnerable areas to cracking is around the lifter gallery between the cylinders. You will know if you have suffered damage in this area is you start to see signs of water in the oil after the engine heats up. Look for moisture that accumulates in and around the oil filler cap on the valve covers. If the block is cracked it probably needs to be replaced with a long block.
 
Thanks for the advice. It looks as though it is one freeze plug on the left side of engine behind motor mount. I looked at the oil and it appeared normal, however I did not run engine up to operating temperature. It is scheduled to be repaired next week. Is it advisable to run engine for 10 minutes to get it to operating temperature?
Tom
 
SeaHarley said:
But that's why the plugs are in there. To hopefully prevent other damage.
Click to expand...

Actually thats just a coincidence. My engines instructor in college grilled us about it all the time. They are simply there to get the sand out of the casting when the block is manufactured. They serve no purpose for protecting a block from freezing.

I think its just that after years and years they have become known as "freeze" plugs due to the fact that they pop out when a block freezes...... most of the time. Sort of like an automotive slang word.
 
Thanks for trying to be a smart ass. I guess I just don't know what I'm talking about. :thumbsup:
 
Followup on freeze plug. Boat has been repaired and is in water and runs fine. The only thing left to do is get it cleaned up. The center freeze plug was replaced plus the 3 point drain valve in the front of the engine. The drain valve was cracked. Lessons learned here are make sure you follow all mfg instructions concerning winterizing especially in cold weather climates. I was lucky this time.
Tom
 
Thanks for the follow up.
Glad it worked out to be "not too bad" this time.
 
Few tips on replacing freeze plugs.

Remove the blown one, they rarely are completely popped out, more like just tipped out partially to allow expansion of water. These plugs may be tough to get out, if you can pull it out with water pump pliers or drive a chisel into the center of the plug and pry out. Avoid scaring the seat which is the block itself.

Acquire an exact match plug.

NOTE: The plug installs with the cup in the plug facing outwards

Lightly lap with wet dry sanding paper or wheel (sand) the opening just enough to remove any rust or corrosion.

Place the new plug in your freezer or pack in ice cubes to get the plug really cold.

Then, take the cold plug and slip it into the opening just until its lip is flush with the block. Hold it there for just a few moments until it begins to warm and expand. It will soon "sweat" in to place. If the frozen plug wont slip easily into place, tap it lightly with a rubber or plastic mallet to avoid damaging the edges of the plug. No mallet, place a small block of wood over the plug and drive it into place with a hammer by smacking the block.

Once in place the plug should be water tight. Observe the plug once the engine is run up to operating temperature. Once you've confirmed the plug is water tight, paint the area with matching engine paint.
 
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