I took my boat in today with my 40 Horse Merc 4 stroke on it. I took it to the same place as last year and wanted them to winterize and store it until spring. The owner called me and said when they were going to change the oil they found it was milky and said it should be looked at by a Merc dealer (they are not). I somehow think this is really bad news and cannot imagine how it could have happened. Anyone had this happen to them? Outcome?
Without a reply from the OP, lower unit milky oil = no big deal. Drain it, change it, get a new gasket for the lower unit vent and plug and you're good to go (assuming no major damage to the lower unit gears).
If it's engine oil...different story.....good luck!
Agree with RC...
Lower unit oil, or engine oil?
are you talking upper engine oil or lower unit gear oil?
I believe you are talking engine oil.
First thing I would check is the thermostat to see if its failed in the open position before any type of panic sets in.