Merc 5.0 V8 chocolate oil

[TheRubberDuck]

Ok, so it looks like I'm most likely screwed but maybe someone has a little insight.
Boats been sittin' 4 years (winterized).

I tried pumping oil before getting engine started a month ago but it was cold and too thick so I decided to wait until I got the engine hot. The oil looked normal but I didn't have enough for fair judgment.

Over the next couple weeks I drained the old gas, put in a new impeller, new gas and fuel/water separator. I put on the muffs. Engine starts right up, sounds great, I let it run until hot.

I drained the (hot) oil. Its noticeably thin, comes out easy and looks like chocolate milk. I put in new oil and oil filter and let the engine run. Then I pump out some of the new oil. It looks a little better but frothy (tiny bubbles). I add new oil, let engine run and then drain a cup. Looks slighty better. Still frothy.

What are my diagnostic options here?
And, also, since the oil may have been fine before engine started and this is the first time its been hooked up to water in 4 years, is it more likely that this is basically a new problem caused by a new crack or something that occurred over the winters.

 

[Bt Doctur]

should have pulled the pan plug and let it drain. If it was wintererized correctly condensation was in the oil lan and was mixed with the oil
Eun it in the water,under load for about an hour. That should boil out any condensation and return the oil to a normal color.

 

[TheRubberDuck]

should have pulled the pan plug and let it drain. If it was wintererized correctly condensation was in the oil lan and was mixed with the oil
Eun it in the water,under load for about an hour. That should boil out any condensation and return the oil to a normal color.

Thank you. I'll give this a try now

 

[TheRubberDuck]

Ok. I did that and decided to pump some oil out to see.
It looks as bad as the first time. Dark chocolate milk.
Any other suggestions?
Things I can do or check?

 

[Rick Stephens]

There are a bunch of places a crack or gasket failure can introduce water. Only way I know to test is to pull and plug the water lines going to the exhaust, cap the inline and pressure test the block cooling system.

 

[TheRubberDuck]

There are a bunch of places a crack or gasket failure can introduce water. Only way I know to test is to pull and plug the water lines going to the exhaust, cap the inline and pressure test the block cooling system.

I hope it doesn't come to that. I'm figuring everything out with the help of people here but I'm definitely in over my head lol

I drained the fresh oil after letting it run for an hour from the oil pan. Now I'm gonna run some more fresh oil through it and drain....and then do it again. Hopefully it starts looking better and the problem was just condensation built up from sitting for 4 years. Fingers crossed that it's not a crack or gasket failure.
I'll take and post pics of each flush of oil

 

[TheRubberDuck]

Well, it's a really subtle change that doesn't show up well(or at all) in the pics but its definitely better than the original chocolate milk pic.
I think Bt Doctur was right about it just being a lot of condensation.
Left is the first oil drain. Right is the last.

 

[Scott Danforth]

only takes about 1-2 ounces of water to froth it like that.

 

[TheRubberDuck]

only takes about 1-2 ounces of water to froth it like that.

That's good to know. I thought it would of had to be significantly more.
But what are you getting it? That it was just a little condensation or that I may have a slow water leak?

 

[Scott Danforth]

change oil 2-3 times, if it doesnt clear up, you have a leak

 

[TheRubberDuck]

change oil 2-3 times, if it doesnt clear up, you have a leak

Well, its not milky or frothy anymore...but surprising dark.
No separation into layers in the jars I set aside. I expected that if there was a problem there would be a tiny layer of water at the bottom