Oil milk shake

[stevenhickeys]

Hello,

I picked up a StarCraft American 20 that has a Chevy 250 / 165 HP motor. I bought it cheap because it ran and shifts and needed a new interior.

The motor oil was old and I ran it very little (no more than 2000 RPM's) due to a gimbel bearing that need to get replaced before I put it away for the season.

I took a friend out on the boat for a ride and opened her up to 4000 - 4500 for the heck of it. There was no temp spike or problems on the water.

Went to change the oil filter and oil last sat and the oil was the consistency of a milk shake. Added new oil and filter thinking the old oil was contaminated from being so old but unfortunately, the new oil has water in it too.

What do I need to do to rectify this situation?

any advice is most welcome!!

 

[thumpar]

Pressurize the cooling system with air and listen to see if you can figure out where it is leaking into the oil side. Do you know if it was winterized last winter?

 

[ziggy]

have a look at #23 from here.
specially look at the second link in that thread.

fwiw. my 75 got milky oil too. my manifold was rusty on the outside bottom edge. i suspected it was rusted though. i took it off and filled up the waterjacket w/water. over night all the water was transferred from the water passage to the exhaust passage. it was rusted through and needed to be replaced. did that and a riser at the same time. that might not be your problem, but it was mine.

 

[stevenhickeys]

Thank you both for responding!!

The motor was winterized last fall and the oil at the end of the season and the beginning of the season was fine

When we took the boat out last time there was no overheating issue. The temp stayed just around 140 - 150 degrees so I don't think the head gasket blew.

I will pressurize the cooling system and see if I can hear where the air is flowing. If I need to replace manifold and the raiser for the motor, are there any recommendations on where I could find decent old parts for this old gal??

 

[stevenhickeys]

Admiral,

You were right on!! I removed the head and manifold and on inspection I found a small hole in the manifold that was most likely dumping water into the 2nd and 3rd cylinder exhaust port. Now, after investigating after market manifolds or even used ones I am looking at between $400-$700 to replace the manifold.

The hole is fairly accessible so I bought some JB Marine weld and sealed the hole and surrounding surface 2 times. I let it cure and it seems to be rock hard.

I was wondering if anyone has used this produce to repair a manifold and whether or not it was successful. I'm sure the chances of it working would have been better if the leak was in the intake port instead of the exhaust port but it is what it is.

Should I take a chance on it and give it a try or did I waste my time and should I save my money for a replacement manifold??

 

[Bt Doctur]

maybe not, pm me .its very risky trying to repair a manifold.

 

[achris]

That hole is on the exhaust passage, right where maximum heat is. For the cost of 400-700 you are putting that engine at risk. When it leaks again you might not be so lucky, it could easily wipe a bearing, then your up for a full engine rebuild AND a new manifold. Why not 'skip the middle man' and just go straight for the new manifold? And that JB weld will not hold in that location.... Especially with the consequence of its failure, I'd not even attempt it.

 

[stevenhickeys]

Thank you both for responding. I had a FEELING this fix would be to good to be true. The fix seems solid and permanent but the heat and exhaust pressure may be to intense for the fix.

The motor is smooth running and in good shape. I would not want to put any more water into her so I guess I'll save my money and replace the manifold like a good mariner should do.