Blown head gasket or cracked head.
Shell Melina S30 marine engine oil color
You must use a special marine oil of 10-40 W or 5-40 W. Normal car and land engine oil does not displace water. Marine oils can be purchased from many large engine oil producers, and there are also companies that specialize in marine oils.
I believe it is of the same color as land engine oil
Mixing oil weights is a NO,NO.
The marine main engine lube oil sump is critical to keep the engine running. If the pump gets clogged or fails, then the engine will seize and be ruined.
intake manifold gasket,head gasket,cracked head,cracked block. was it overheated? was cold water added to hot engine?
From The Information You Have Asked. You Have An Engine. There Is No Engine That I Know Of Where The Oil And Water Run Together. So The Answer Is NO. You May Want To Change Your oil After You Get The Engine Back Together And Running. But No You Do Not Need To Drain The Oil Out To Change The Water Pump.
the oil
Water in the oil is a telltale sign of leaking cylinder head gasket.
it should not be a water in oil tank it is mean engine cracked
oil is milkey white or foamey