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K. Kergan
K. Kergan, Marine Mechanic
Category: Boat
Satisfied Customers: 1031
Experience:  24 yrs exp. Inboard/Outboard mechanic Mercury/ Mercruiser, Volvo Penta and OMC, Johnson/Evin.
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I have a pair of 4-71's in my landing craft. 1 has been rebuilt

Customer Question

I have a pair of 4-71's in my landing craft. 1 has been rebuilt an the other not,,the older one has always used oil but I just launched it for the year and now it's making oil, milky color, I can't tell if it's water or fuel. What do you think? Thanks in advance.
Submitted: 2 years ago.
Category: Boat
Expert:  K. Kergan replied 2 years ago.
Hi, my name is Kerry
If the oil is getting fuel in it, (either gasoline or diesel), it will not change color except to get thinner and more translucent.
Also, the engine oil will smell like fuel.
If the oil is getting milky, you have water leaking into it.
This could be a head gasket, a leak in the exhaust manifold or riser or something else.
In any event, you have water getting into the engine oil.
Customer: replied 2 years ago.
To generic of an answer,,I don';t need your services. Kerry never even addressed the fact that it was a Detroit Diesel,,, take me off of you list,,,gone.,,,,fini,,,no more payments,,,,,,,,,,, Jim
Expert:  K. Kergan replied 2 years ago.
I know what a Detroit Diesel is, I told you it does not matter if the fuel is gas or diesel, it will not make the fuel milky.
Have a nice day!
Look for a cooling system leak!!!!
In fact, drain and pressure test the cooling system, you will find your problem.

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