mercury 9.9 bigfoot water in oil

[kevind]

Just asking for advice from some more experienced people out there. I just went to check my oil levels on the kicker when i saw the milky white and watered down oil. oil level is much higher and its white at the dipstick and the oil fill locations. pulled the spark plugs and i didnt notice any white on the plugs but they did have a little red moisture/liquid around the threads. Its a 1999 4 stroke. I changed the oil this year before i started using it and it was fine. What should i be looking at to start?

 

[sudsy]

Check thermostat

 

[kevind]

would that allow water into the motor?

 

[sudsy]

Had milkey oil before on a merc and it was "making oil" from a stuck open thermostat. Basically engine running rich and un burnt gasoline getting by seals which causes milky oil.

 

[terrin]

Check thermostat

x 2. replace thermostat.

 

[kevind]

the oil did smell of gas but i thought that the gas wouldnt turn it milky white

 

[Oly1]

Might be the shifter rod seal as well. Buddy just had his replaced at a dealership. Same engine and same observation. Except his oil didn’t smell like gas.

Oly

 

[kevind]

Might be the shifter rod seal as well. Buddy just had his replaced at a dealership. Same engine and same observation. Except his oil didn’t smell like gas.

Oly

How did they find out it was the shift rod seal? Curious to know if I should be looking for something.

 

[Rotten Ronnie]

Thermostat x3, if the thermostat is stuck open ,the motor will run cold. Water from normal combustion will collect in the oil over time if the oil doesn't heat up enough to evaporate the water and vent it.

 

[scott craven]

the oil did smell of gas but i thought that the gas wouldnt turn it milky white

Gas won't turn it milky, you have water entering somewhere.

 

[trophywife]

would that allow water into the motor?

no.

head gasket.

 

[kevind]

So would a compression test show a head gasket leak or does it have to be a leak down test? Also if I use a inspection scope to see in the cylinder would that help confirming a head gasket leak?

 

[sudsy]

If your headgasket is shot your motor wouldn't be running.

Pop off your thermostat and I bet its stuck open. Put in a new one and you'll be good to go.

This is a common problem with early merc four strokes. Call the merc dealer I'm sure they will tell you the same.

 

[Wild Bill]

Why not start with cheap and simple thermostat, known issue and all... engine and engine oil temp never getting warm enough to boil off crankcase gasses and moisture. Probably what a shop would do.

 

[the fog ducker]

Kev
my yami was makin oil , mine was from a bad fuel pump ,the oil did not go milky ,
it went thin , clear like oil still , but wreaked of gas , changed the pump , golden..
change your stat as guys on here recommend , cheap n easy , but , im thinkin its deeper than that ,
fingers crossed for ya though....
if not , we will tear it down this winter , shouldn't be to difficult to get to the head gasket....

fd

 

[AlK]

Had a bad thermostat on my Yammy, oil was not milky, it was making oil and the oil smelled of gas and it had a pinkish tinge, similar to the colour of gas I was using.

 

[Enniberg]

Had pretty much the exact same problem a few years ago - oil was very milky and level increased a lot. Changed the thermostat and the problem was solved.

 

[kevind]

Took out the thermostat and it's open a little so hopefully that is the problem but I've attached some pics so you guess can see.

 

[Enniberg]

Took out the thermostat and it's open a little so hopefully that is the problem but I've attached some pics so you guess can see.

my thermostat and oil looked virtually the same as in your pictures.

 

[kevind]

my thermostat and oil looked virtually the same as in your pictures.

How did you flush the engine? Did you just drain it and put in new oil and filter once?