Is this a blown engine or blown head gasket ?

Engine: 1999 Volta Penta 4.3L 120 HP

I winterized the boat early last fall, removed both screws that goes behind the manifold, the two screws on each side of the block and the inlet and outlet water pump hoses (learned that with a marine mechanic). Have been doing this for the last 4 years, no problems. This last winter was mild down here in OK. Yesterday, first time I take the boat to the lake and after a few hours of riding and stopping, getting ready to load the boat back, I noticed the engine beeping and almost cutting off on idle. Opened the engine compartment and noticed oil and water mixed (milky combination) flowing out of the top of the carburator area. Talking about a shocking experience here!!! Cut off the engine right way! Pulled the dipstick and the mix of oil and water is all the way to the top. I am praying for a blown gasket, but all the posts I ready point to a crack on the engine. Also I had to get something in the engine area a few minutes before riding it back to the dock and did not see any problems or oi+water overflowing. So it seems like it happened on the way back to the dock. But it could be running like that since I put it on water. I am not a mechanic, but I would think if I got the water out of the block, manifolds and pump hoses, at least if it is a cracked engine, it should not be in the block. What do you think? I saw a lot of water come out of that engine. Where else would water be hidding enough to crack the engine ? Or could it be something else ? What is the next step here and how much an I looking at spending ? Thanks

Re: Is this a blown engine or blown head gasket ?

4.3s can get cracks in the intake manifold that cause exactly what you are talking about. Also, normally the number one through about number four most common reason for water to be ia marine engine is bad exhaust manifolds/riser/gaskets. That usually doesn't cause the water to mix with the oil, but you need to check it all out.
Get the block and the oil drained asap. Fill the cylinders with oil, in case there is any raw water in them. That way, you won't be left with a rusting hulk of steel/iron.

Re: Is this a blown engine or blown head gasket ?

Thanks, starting to fell better. SO do you think that by removing the water the way I described can rule out the option of a cracked block ?

Re: Is this a blown engine or blown head gasket ?

No you can't rule out a cracked block. It is possible for water to get trapped in the block, due to dirt and stuff that didn't let it all drain. It's happened before and it will happen again.

Re: Is this a blown engine or blown head gasket ?

just curious, when you removed the plugs did you rod the hole with a nail ,screw, wire, etc to make sure it drained fully or just take out the plugs.

Re: Is this a blown engine or blown head gasket ?

Bt Doctur said:

just curious, when you removed the plugs did you rod the hole with a nail ,screw, wire, etc to make sure it drained fully or just take out the plugs.

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No, sir. I think this could be the problem. Are you referring to the exhaust manifold plugs. I just removed them like I normally do every year. Did not think of doing that. Does the same need to be done on the block plugs ? Also, Say water was trapped on the minifold, would it affect the block also ?

What is the next step ?

Re: Is this a blown engine or blown head gasket ?

different,pull the manifolds first and check them, pull the head and look.

Re: Is this a blown engine or blown head gasket ?

Sorry, let me clarify. I don't know if water got trapped, but there is a possibility. Where does it normally get trapped should have been my question ? Down at the block, even with the plugs out (gravity would take care of that one I would think - wishful thinking) or would it be most likely be trapped at the exhaust manifold ? Thanks again,.

Re: Is this a blown engine or blown head gasket ?

If there is dirt in the water passages, it is everywhere. In the exhaust manifolds, in the block, in the intake manifold. And yes, you need to take a wire and ream out all the drain holes when you winterize. Sorry you didn't know that.

Re: Is this a blown engine or blown head gasket ?

Thinking the worst happened. What would be the cost to fix a split block at a marine shop ?

Re: Is this a blown engine or blown head gasket ?

Recently had the same problem with a 96 Volvo penta 4.3 and I can tell you what I did. I did all the work myself and here is the steps I took and I'm not sure you are going to like the last part... Took of heads, intake, risers and manifold and bought all new gaskets and replaced them all(had the heads planed by a machine shop). The engine washed again. Thinking it might be a cracked block I still took off all the above parts and sent them to a machine shop to be tested. For piece of mind, and what would have been the cheapest fix. I knew the machinist so all the testing was .... lets say cheap for me.... Everything came back fine except for quite a bit of rot in the risers. Bought a new crate motor for $2000. The total bill was around $3000 with all the new gaskets, plus I replaced the risers, water pump, and starter(snapped a post off of it when removing) so deduct about $500 for those additional parts so you are looking at about $2500(best guess for this area) for parts alone. As for labor.... they don't make money in sums large enough for me to do that again... I have done 5 motors now... 4 in cars and this one in the boat and this was by far the most challenging one, to say the least. Thanks to Don S. I worked out the kinks but if the engine does need to be replaced you will have to go down to your local marina.. see what they have for engine prices, ask how many hours it will take to install the new one and see what they get per hour for labor.

Re: Is this a blown engine or blown head gasket ?

Bubba1235 said:

Run a pressure test on the engine cooling system. Until then you are just guessing and that gets VERY expensive.

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Here is what I found out today. I noticed the alternator belt is so loose that I can turn the alternator with my fingers. Would this make more sense to cause the engine to overheat since it appears that the water pump would not pump any water into the engine ? I wonder if it cooked the head or if is just a gasket. The boat was kept in an insulated barn all winter with cover on top and closed engine compartment.