Water in engine oil

[Jan Rundegren]

I have a 2001 Mercury 75hp 4-stroke outboard, which started to show milky engine oil. This oil is most likely contaminated with water. What reasons could there be for water leaking into the engine compartment?

 

[Iceman66]

Re: Water in engine oil

Your head-gasket is probably gone, leak between oil and water canal.

 

[1nebel0]

Re: Water in engine oil

Negative on the head gasket...These motors are know for making oil...Google it or ask you local shop... Ihave a 115 that I bought cheap with the same problem...90% of the time it is the thermostat letting the motor run too cool and condensation forming in the oil.. It is a well know fact for all 4 strokes and a problem not solved a lot of the time.. my 115 did not have a bad thermostat and I have pickled the motor 4 times trying to get the water out...running the motor on the hose for half and hour and the oil never even gets luke warm....They are saying before you put the boat away to run the motor at full throttle to heat it up and burn out the condensation..Again, this is a very know fact on these motors so please google making oil or water in oil in outboard and you will have plenty to read about..If yours is not a thermostat problem, flush the motor with cheap oil.... at least 3-4 times and run it in between to heat up the oil... I am running straight marvel at idle in mine to try and get the remaining water out....the other problem is with the ethanol attracting water and without a top notch filter system you are carrying water into the motor with fuel...My 115 sells for $12,000 and the owner traded it in to the shop I bought it from who was an Evinrude dealer and didn't know about the Merc's(Yamaha's) making water..... I paid $500 for a $5000 motor used as they wanted it out of their shop...The guy bought a brand new Etec..had enough of 4 strokes...check it out......

 

[Pepper2482]

Re: Water in engine oil

Water condensation would not make milky oil in your case. You would have slight milky substance on your oil fill cap and maybe some on your lifters. I fought this till I took my engine apart maged the head and found a crack between exhaust and air intake. Is your oil dip stick rising any? What thermostats do u have in?

 

[1nebel0]

Re: Water in engine oil

While we all have our opinions, stop by your local shop and ask them..They see it all the time with the 4 strokes...Yes a motor running too cold will create enough condensation to cause you engine to make oil is what they call it..when you pull the plug you will get a half a cup of water or more...this is not slight condensation........Yes it can be a crack as that happens but the more common problem is running too cold....