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Water in King Cobra engine oil

I

ivydawg

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"1988 28 ft bayliner with OMC

"1988 28 ft bayliner with OMC Cobra 460, 750 hours. Boat new to me last summer. Blew out the coupler before the winter, so I had it pulled out of the water to get it fixed. Back in the water after the fix and the boat overheated before I got 1/2 mile from the repair dock. Impeller (?) was toasted. Clearly their fault so they fixed a cracked exhaust manifold/riser and gave it back to me. Boat spent the winter where air temps dropped into the teens, river never ices over. Kept a light on the engine and fired it up every few weeks. Never really checked the engine oil when I got it back from the shop, but now that I do, I see that's it's mixed with water. Guess the question is what's wrong (please don't say cracked block) and who's fault is it? In particular, is there water in there because it was overheated or did I not do enough to protect it from the cold over the winter? Or option #3 (which I'm personally pulling for) it's normal to have water in the engine oil and I'll have thousands of hours of continued pleasure with my boat without any more significant expenses."
 
"Water expands one ninth in vo

"Water expands one ninth in volume when the temperature drops below freezing and, yes, it's your fault for not winterizing the motor properly.

Sorry, but I call 'em as I see 'em.

Jeff"
 
Ouch happy motor hunting....yu

Ouch happy motor hunting....yup Jeff has called that one right and strike three your out looking for a motor package.
 
"Okay, so I'm stupid, but

"Okay, so I'm stupid, but I don't get it. Where's the water coming from and why did the block (aparently) crack? The engine is protected by antifreeze. There's water from the fresh water cooling, but how does that affect the block?"
 
"Your cooling system has a hea

"Your cooling system has a heat exchanger, which could have frozen previously and if there was enough dilution of the anti-freeze, it will expand enough to crack things, even though it looks green. Did you check the anti-freeze for its freeze point? This is best done with a refractometer.

It's also possible that you have a bad head or intake manifold gasket."
 
If you ran the engine for only

If you ran the engine for only short periods of time you will get moisture inside of the block from the hot cold hot cold. ( I winterize my motor and find it best to not run unless i plan on running for e few hours to heat up the crankcase and evaporate the moisture that will build from temp changes.
Change your oil and run your boat 3-4 hours and see if you are getting water in the engine.
 
"If the overheat was bad enoug

"If the overheat was bad enough to crack exhaust parts, I'd suspect it might be hot enough to warp heads. The 460 has BIG heads, that cover a lot of area, and like the Merc closed circuit 460 headed 4 cylinders, they warped easier than others. A compression test by a 3rd party marina would possibly indicate a head gasket problem. There should be NO water in the oil, there should only be antifreeze. If there's water, get the oil changed and hope it's just condensation. I'm guessing if you didn't drain the heat exchanger, manifolds and power steering cooler, you didn't change the oil either? Old oil from last season will sometimes go milky white for the first few hours due to the moisture it absorbs over the winter. ALWAYS change engine oil in the fall, so as to avoid soaking bearings and other important engine junk in dilute sulphuric acid(a by-product of combustion)for 6 months."
 
"Let me rephrase. There shoul

"Let me rephrase. There should be no water OR antifreeze in the oil. If there's water, it's probably condensation, if there's antifreeze, head gasket or cracked internal jacket. Tired...It's May, and I work in the marine industry."
 
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