5.0 omc water in crankcase

[ShilohT]

Hi ya'll I'm new to the group and have looked at a few cases of water in the crankcase but haven't found anything to my exact problem. I went to change the oil, just bought the boat, I ran it for a few hours on the lake. I found milky oil but the boat ran like a top with no issues. My concern is, I don't want to immediately go into tearing into the heads. Any ideas before I start testing? There is no water in the cylinders themselves and I'm limited to testing right now as we've had freezing temperatures lately. I did winterized the boat at the end of the summer and I have cranked it over since and it fired right up.

 

[southkogs]

Welcome aboard Shiloh:

Have you compression tested the cylinders?

 

[bruceb58]

There are a number of ways your oil can get milky. Starting from the worst case:

1) Cracked block/heads
2) Leaking exhaust manifolds
3) Rain water entered the engine
4) bilge filled with water an water seeped through main oil seal(have experienced this myself)

If your oil level went up considerably, you may have issue #1 which would require you to pressure test the cooling passages.

If your engine has been operated in salt water, your manifolds could be corroded or cracked allowing water to enter the cylinders and seep by the rings.

 

[Scott Danforth]

define the milky oil you found. a bit of frothing under the valve covers and black oil in the pan is common - moisture from condensation and combustion process that has not burned off yet as the motor did not get warm enough

chocolate milkshake oil in pan - you have a problem. could be any one of the ones mentioned above including a bad head gasket.

 

[ShilohT]

It was a nice creamy milkshake and no I have not compression tested yet due to the weather. I bought the boat from Kansas so I assume just freshwater is all that was ran through it

 

[strikemike]

you have to check compression first. Maybe its just a blown head gasket.

 

[Bondo]

It was a nice creamy milkshake and no I have not compression tested yet due to the weather. I bought the boat from Kansas so I assume just freshwater is all that was ran through it

Ayuh,..... Welcome Aboard,.... Is it a 5.0l Chevy motor, or a 5.0l Ford motor,..??

How much of this milkshake did ya drain out,..??

How high, over full was it on the stick, before ya drained it,..??

Have ya got it winterized, Dry, or with antifreeze,..??

Rather than a compression test, I'd start with a Coolin' System Pressure Test,.....

Drain the block, isolate it, 'n pressurize with 'bout 15 psi of compressed air,....
It oughta hold it for a long, Long time,...

 

[jerryjerry05]

Year? Model# The others have covered almost everything.
Possible, you have an oil cooler and it's leaking back into the system.
Post all info for your motor.