milky oil? I know

[Elkiller]

O.K. I know what oil looks like if you crack your block. I did so many years ago as a new boat owner, and it was frothy and obviously contained some water emulsion.

Today- I had really done the best job ever of winterizing the boat. Ran straight antifreeze in all the hoses, out the petcocks, turned the motor over and did it again. When I started the boat today, the first water out of the boat engine was green, so I know it was full of antifreeze. After I changed the oil, the new oil looked cloudy brown. I pumped it out, while adding new until the oil was very clean. Added new filter and started it again. Same result, a dirty brownish grey color, not really emulsified, but obviously something very wrong. Boat runs fine, exhaust seems clean.

Is this another cracked block or do you guys think it could just be a crack in a manifold, adding exhaust where it doesn't belong? Any guesses would be appreciated. I know this will cost me. It is a 4.3L merc inboard.

[pathfinder]

It also be a loose intake mainfold , Maybe even a cracked one.:twocents: A budy of mine ahad a 455 with a tunnel ram and kept quashing his gasket.....

[cutbait]

cannot I/d your problem but you said straight anti-freeze? straights not safe must be mixed.Did you drain it first?

[gordy]

I ran anti-freeze at too high a ratio years ago and it turned to slush.
Definately want to thin the product down to the 50/50 level or it is pretty much the same as having no anti-freeze at all.
Hope you find a cheap fix to the problem.

[CC25]

Go with the non-toxic RV type next time.. You don't have to worry about a 50-50 mix, and its better for the environment. Its cheaper too!

You might have something as simple as a bad head gasket. Have you checked compression?

[Elkiller]

I'm thinking bad head gasket. Will be the first thing I check.

[AlseaAssassin]

When you ran your boat did your exhaust smell oily?? I never noticed the tell-tale blue smoke or white smoke emitting from my exhaust ports but I did smell oil. My oil had the same coloration but I haven't diagnosed the problem yet as there have been no external signs gasket failure other than it cutting out at wide open throttle. Please keep us posted, I might be in for a new gasket as well.

[Elkiller]

Well, I am about 90% sure problem is solved. Thanks to the guys at Clemens Marina in Eugene. They looked at the oil and thought the coloration was just a little old oil and a tiny amount of water that got there during storage, it did rain on the boat for a few weeks before I got it covered, and the water did drip onto the motor by running down the back of the motor cover. Anyway- they said to take off a valve cover and run the boat, allowing the oil to evaporate the water in it. I just took out the oil fill spout and the pcv valves and ran it for about two hours total. You could see the vapor coming out of the openings in the valve covers. I stopped the engine every 15 minutes and checked the oil to make sure no water was coming in. It now looks almost clean, like new oil after about two hours at idle. Engine runs smooth and quiet and clean. I think I got lucky!!!!

[jmd]

that's good. Sounds like you have it coverd.