4.3 liter, oil in water

[Lou Bischoff]

I have a 2000 4.3 liter Mercruiser I/O. I noticed water intrusion in the crank oil upon an oil change. Changed the oil 2 more times, but still have a tan milkshake. The engine runs beautifully. Starts right up, no knocking or idling issues. I winterize by draining 5 blue stopcocks, probing the block openings with a wire, and filling the water pump hose with pink antifreeze. Cylinders are fogged with oil. There is no water on the spark plugs upon their removal. A water pressure test reveals a slight hissing in the oil filler spout at 30 PSI. Compression test (cold) reveals all cylinders but #3 at 165-175 PSI. Cylinder #3 is at 95, and rises to 105 after squirting oil in that cylinder. Any chance my issue could be a head gasket or intake manifold issue, and not a cracked block?

 

[achris]

.... and filling the water pump hose with pink antifreeze.... A water pressure test reveals a slight hissing in the oil filler spout at 30 PSI. ....

That, and the fact that water keeps entering the oil, sounds like a block crack to me. Probably caused by a pocket of untreated water being caught in the block once it was filled with 'anti freeze'...

In future, leave the block empty, if you do have a small pocket of water and it freezes, it'll expand into void, and not crack the block....

Chris..........

 

[Lou Bischoff]

Thanks, Chris. I never filled the block or exhaust manifolds with antifreeze. I added just enough antifreeze to drive the water out of the impeller intake area. The stopcocks were left removed all winter. Any thoughts on that ?

 

[achris]

"A water pressure test reveals a slight hissing in the oil filler spout at 30 PSI. "

Says you have a block or head problem.

 

[Lou Bischoff]

Thank you !