1999 MerCruiser 3.0L with water pouring out

[thomas.seay]

I have a 1999 MerCruiser 3.0L and when I connected the water hose to it this morning for my test start before going to the lake, I noticed that I had water pouring out of the block behind the alternator. I found a small round (about 1.5" diameter) plug at the bottom of the bilge. I found the hole where the water is coming from and it appears that this plug goes there. I need to find out how I should put this plug back into the opening. What, if anything, should should I use to adhere the plug back into the hole. It's a tight fit, so I could use a rubber mallet to get it back in. Any suggestions?

Thanks,

 

[Howard Sterndrive]

Re: 1999 MerCruiser 3.0L with water pouring out

clean the bore with some sandpaper.
find a big socket and matching extension that fit snugly into the plug.
put some automotive sealant on the outer diameter of the plug and drive it straight in with a hammer.
not a rubber mallet... you would get nowhere with that.

then say a prayer that the plug being out is not evidence of a cracked and destroyed block from freezing
but aside from ice...not much else could make it pop
was the engine winterized properly?

 

[thomas.seay]

Re: 1999 MerCruiser 3.0L with water pouring out

Thanks for the tip. I live in Georgia, and this was my first year with a boat, so no I did not winterize it. I am hoping that I don't have a cracked block.

 

[thomas.seay]

Re: 1999 MerCruiser 3.0L with water pouring out

What exactly is that plug?

 

[Bt Doctur]

Re: 1999 MerCruiser 3.0L with water pouring out

The proper name is a "core plug" improperly referred to as "freeze plug"
Allows the manufacturer to get rid if the sand in the mold.

 

[fat fanny]

Re: 1999 MerCruiser 3.0L with water pouring out

If you get that plug back in I would look that 3.0 over real good before taking her out those plugs just don't pop out for no reason. check all fluids and cylinder compression.

 

[thomas.seay]

Re: 1999 MerCruiser 3.0L with water pouring out

Thanks to all that provided input on my issue. I have looked the block over and there doesn't appear to be any cracks. I am going to replace the plug and then go from there.

Thanks,

 

[HT32BSX115]

Re: 1999 MerCruiser 3.0L with water pouring out

Thanks to all that provided input on my issue. I have looked the block over and there doesn't appear to be any cracks. I am going to replace the plug and then go from there.

Thanks,

Well,

that doesn't mean you do not have a crack.

The 3.0 engine frequently cracks up under the intake manifold an inch or so below where the head bolts on. You can't see it by looking in there unless you have a bright light and a mirror.

I replaced a 3.0 last summer that had a cracked block and manifold because the owner didn't winterize.

None of the core plugs were "popped' out.

Good luck....


Rick

 

[thomas.seay]

Re: 1999 MerCruiser 3.0L with water pouring out

HT32BSX115,
On my first inspection, I did not see or feel any cracks. Nor were there any "rust trails" on the side of the block, so I am keeping my fingers crossed. I was told that what I found was not a Freeze Plug, but instead of a Core Plug, so isn't "popping out" what it should do? I know that is the case with Freeze plugs. I am praying that all is well with the ol' Bayliner. I have learned my lesson about Winterization.

 

[burp]

Re: 1999 MerCruiser 3.0L with water pouring out

The proper name is a "core plug" improperly referred to as "freeze plug"
Allows the manufacturer to get rid if the sand in the mold.

There isn't much that will cause a core plug/freeze plug to push/pop out other than water freezing in the block.

Consider yourself VERY lucky if that is the only damage done. By not winterizing you save a few $'s but in the end you will be spending way more.

 

[HT32BSX115]

Re: 1999 MerCruiser 3.0L with water pouring out

I know that is the case with Freeze plugs

There's really no such thing as "FREEZE PLUGS"

They're only core plugs to close the holes in the blocks/heads/manifolds that are there ONLY for the casting process.

They sometimes pop out due to water freezing in the block (hence the moniker "freeze plug") or they pop out due to coolant pressure in the block, or due to corrosion where they contact the block, or other reasons (maybe loose from "day-one")


The holes are for only for the reasons above.

If you have water in the block and it hard freezes, there's nothing that will prevent the block from cracking. If your block is not cracked. The water in there did not freeze hard enough.......and you were lucky.......(luck usually isn't in the equation though)


Good luck however!


Rick

 

[bamadave]

Re: 1999 MerCruiser 3.0L with water pouring out

Time to put the muffs on it in the driveway and run the engine for a while. Keep checking oil and level for water and level increase. Just because you don't see a crack on the external side of the block doesn't mean the inside of the block is ok. Do all the checks you can before taking it to the lake and getting out on the water and getting stranded from milkshake coming of the engine. Good Luck!

 

[HT32BSX115]

Re: 1999 MerCruiser 3.0L with water pouring out

Even if you do have a crack you might not see water flowing out of it....

A raw water cooled engine doesn't have pressure on it like a closed cooled engine.

Hairline cracks may not seep water at all and rust lines may not appear for quite some time.

For a lake boat it probably won't hurt anything either.

 

[thomas.seay]

Re: 1999 MerCruiser 3.0L with water pouring out

Not to sound like a complete novice, but how do I know which type of cooling system I have (raw water cooled or closed cooled engine)? I bought the boat used last year and I cannot find anyhting in my paperwork that would tell me.

Thanks,

 

[thomas.seay]

Re: 1999 MerCruiser 3.0L with water pouring out

I think I have answered my own question. I checked the Service Manual and then looked at my boat. I don't have a Heat Exchanger, so I am assuming that means that mine is Raw Water. Thanks so much for everyone's help. I hope to start working on her today.

Thanks,