Milky engine oil after taking boat out
 

I have a 1987 wellcraft antigua with a 454 7.4L mercruiser. Raw water cooled. My oil was fine all summer and about 2 months ago I towed a capsized boat to shore this was really hard and my boat was quite weighted in the stern. I checked my oil the next day and it was milky. took 3 changes to get it clean again. Oil stayed fine all summer right up unitl I pulled it out of the water this weekend (with crane onto a craddle). I went to winterize it and again my oil is milky. When it happened the first time I checked my risers and they were fine.

any thoughts on why all of a sudden I have chocolate milk for oil? could the liftign caused water from the exhaust to get into my oil? I am really frustrated i have no clue any help would be great.

Thanks,

My first guess would be exhaust,but you checked that.I doubt that lifting the boat out could cause it either.As for towing the additional strain on the motor...maybe.
Right now I am thinking that as its getting colder you may have a head gasket leaking.Its taking longer for the engine to come up to temp and its leaking then.
You got all winter yank the motor and find out why.

Remember, condensation inside a motor - particularly when it gets colder - is normal. When you run your motor for longer periods of time, the condensation gets cooked off by the heat of the motor running. If you just ran your boat for a brief period of time getting it from the dock to the crane, you might not have cooked everything off.

Before you do anything serious, do a compression and leak down test.

I would also suspect an intake gasket, they rot around the coolant ports and will dump water right into the oil.

Fixx
 

all the above also check the exhaust flappers in the y pipe,may be getting some backwash water whyle the boat is sitting.

Also how milky just a trace...or tan or white.

Thanks guys here is some more info:

I have had oily water coming from the crankcase vent hose all summer even when my oil was fine on the dipstick.

right now the oil is looking like chocolate milk or coffee with cream in it, a tan color. not sure if thats a lot or a little. i think its alot of water the level is high on the dipstick. this is why i think something happened to letin a lot of water at one time. The week before there was no sign of water in the oil.

where should i start? Take the risers and intake manifolds off?

thanks again

It is going to be one of these listed. Listed in order of most probable cause.

Bad riser gaskets
Cracked manifold or riser
Bad intake gasket
Bad head gasket
Cracked head
Cracked block

What should i do first? does the fact that it only seems to get water all at once after no water for along time mean anything?

thanks,

Pull the oil cooler and check it for leaks.

Pull the risers first. Look down inside the manifolds for water or deposits where water has been running down.
I'm not sure why it happened so far apart. Were you idling a for long time both times????

what does the valvetrain look like? If there is no condensation there I doubt thats the problem .....m

Pull your spark plugs out and disconnect your coil, and have someone turn the motor over while you watch to see if any water is exiting the cylinders. Often you will see water comming out of the cylinder that is effected. Also attempt to read the spark plugs. Typically they should be a light brown . If you have water in a cylinder it should be quite evident. Don't turn it over too much keep in mind you are dumping raw fuel out of the cylinders and you do not want a fire.

As stated if there is a problem cylinder that plug will be very clean ...also when checking the plugs you can usually see beads of water on the plug (look closely) from the bad cylinder .....m

I will check my plugs tomorrow and post. i would have had it ideling for about 10 min just to warm it up to move it to the crane. I dont think that is too long is it?

As for the valve train i have white/tan oil water foam under my oil cap and coming out my crankcase vent hoses intyo my flame arrestor. This has been there for as long as i have owned the baot 2 years, i was told that it condensation and isn't a big deal for a 1987 boat. Is that true?

thanks,

I have same problem
 

Did you find out the problem? I have same issue.

Exhaust manifolds

A reputable marina can pressure test the cooling system. From that the leak can be pinpointed. I would do that before wasting time and playing the guessing game.

I just found my leak, it was intake gaskets. They were pouring!!

Ted G wins
 

ted you missed your calling

Hi, have exactly the same problem on Volvo Penta, fluid way up the oil dristick, and wonderful color of brown on oil filler.
What was your solution? How did it end?

Cheers.