OMC V-6 / 3.8 liter core/freeze plug

[erl629]

Summerizing our SeaRay. Opened the engine hatch to close water drains and attach hoses. Found what appears to be a freeze plug lying in the bilge but the front two are intact. Where else should I be looking? Is there an exploded diagram I could look at to show me location of other plugs - if there are others.

 

[Scott Danforth]

Re: OMC V-6 / 3.8 liter core/freeze plug

if you found a block core plug, you have freeze damage from improper winterization. the only other time I have ever seen a core plug come out is when the block rusted away.

I would replace the core plug, pressurize the block, and say as many prayers as you can hoping you do not have a cracked block.

if you have a cracked block, replacement 229 engines are hard to come by.

if you do not have a cracked block. buy a lottery ticket.

core plugs are in the water jacket just under the heads. there are two behind the flywheel on some engines.

 

[Boomyal]

Re: OMC V-6 / 3.8 liter core/freeze plug

The fact that you found a 'freeze' plug in the bilge tells me that it was not properly winterized. The only thing to do at this point is to re-install one, run the engine and pray. Run it for a short period then stop and check the oil for any signs of moisture. They do not just fall out. It had to be pushed out. If you see any signs of moisture in the oil, drain it immediately then go looking for cracks in the heads or the block.

I had this happen to me once with a SBF. Inquiries at the time stated that just because I showed no sign of water, on the muffs, that the real test would come when I took the boat out and ran it up to temp, under normal operation.

Turns out I dodged the bullet. I had moved to a colder climate from So Cal and freezing was never even on my radar. The next winter, I 'drained' the blocks but never probed the drain holes. Needless to say the water was never fully drained and the next spring, the block was cracked. Good luck.

 

[erl629]

Re: OMC V-6 / 3.8 liter core/freeze plug

Hoo Boy, Tried the lottery once when it was up over 240 M didn't get one number right...
So I can see the two freeze plugs in the engine facing the bow. I am assuming there are two facing aft correct? Are the others? Felt around but the engine compartment is cramped and can't reach anything definitive. Are we talking pulling the engine to replace the plug and pressurize?

Any source for an exploded diagram on the web I don't know about?
Thanks very much for the help so far!

if you found a block core plug, you have freeze damage from improper winterization. the only other time I have ever seen a core plug come out is when the block rusted away.

I would replace the core plug, pressurize the block, and say as many prayers as you can hoping you do not have a cracked block.

if you have a cracked block, replacement 229 engines are hard to come by.

if you do not have a cracked block. buy a lottery ticket.

core plugs are in the water jacket just under the heads. there are two behind the flywheel on some engines.

 

[erl629]

Re: OMC V-6 / 3.8 liter core/freeze plug

That's a sad story. Hope I don't have one of my own. The drain holes were opened but probing them? Nope...
Thanks very much for the help so far!
Any source you might know of for an exploded diagram on the web I don't know about?

The fact that you found a 'freeze' plug in the bilge tells me that it was not properly winterized. The only thing to do at this point is to re-install one, run the engine and pray. Run it for a short period then stop and check the oil for any signs of moisture. They do not just fall out. It had to be pushed out. If you see any signs of moisture in the oil, drain it immediately then go looking for cracks in the heads or the block.

I had this happen to me once with a SBF. Inquiries at the time stated that just because I showed no sign of water, on the muffs, that the real test would come when I took the boat out and ran it up to temp, under normal operation.

Turns out I dodged the bullet. I had moved to a colder climate from So Cal and freezing was never even on my radar. The next winter, I 'drained' the blocks but never probed the drain holes. Needless to say the water was never fully drained and the next spring, the block was cracked. Good luck.

 

[Howard Sterndrive]

Re: OMC V-6 / 3.8 liter core/freeze plug

there are 8 core plugs on your motor as i recall- two facing each direction.
Pioneer makes a brass core plug kit for chevy V8's that will work for you. NAPA might sell an individual one but usually they sell a box of 24 or something so the Pioneer kit usually cheapest option. google it up.

 

[Scott Danforth]

Re: OMC V-6 / 3.8 liter core/freeze plug

your 3.8 liter is a GM 5.0 missing cylinders 5 and 6 then squished together. very short lived in the automotive market. shorter lived in the Marine market.

If it is shot, source a 4.3 liter and go that route.

here is a link to an exploded view of the 4.3 http://www.tonkinonlineparts.com/images/parts/gm/fullsize/060117TX00-055.JPG

 

[Howard Sterndrive]

Re: OMC V-6 / 3.8 liter core/freeze plug

he would need a much rarer 4.3 as the 4.3 went to a 1 pc rear main seal in 1986. needle in a haystack trying to find a 4.3 w/2 pc rear main to fit the stringer coupler.
229's aren't that rare - Rapido usually stocks one.

 

[Scott Danforth]

Re: OMC V-6 / 3.8 liter core/freeze plug

I believe that flageship offers conversion kits with a different coupler. would have to call to check. Untitled Document

I also know that the button coupler can be re-machined to fit, however it is hardened to Rockwell C 56, and takes the proper tooling. Carbide wont last, I think it was a diamond cutter we used in the lathe