Milky oil?

[myu]

I finally got my 1985 OMC started... I noticed it was leaking oil so i put more in and idled to see where it was coming from, but it was still leaking and when i checked the dip-stick it was milky (water in the oil i believe). Cracked motor block is my first guess but it doesn't make sense because it has always been properly winterized... I'm just wondering what if there are some other signs of a cracked block, and if there are any other problems that lead to milky oil?
thanks
Mac

 

[Bifflefan]

Re: Milky oil?

It could be a head gasket, or on some engines a water pump also.
Where is the oil leaking from? if out from where the head mates to the block a head gasket is a good bet.

 

[MPII]

Re: Milky oil?

There have been some service bulletins I have read on this. Typically, it would be a cracked block, however, it can also be a bad intake gasket, blown head gasket, cracked head, or bad exhaust manifolds/gaskets. One a Mercruiser 4.3LX, I had a exhaust manifold gasket go bad and water was coming in on top of the valves and when they would open water would run down into the motor. Once replaced, it was fixed.

You should have a leak down test on each cylinder and see if they hold pressure. That will tell you if the head or head gasket is going bad. It will also tell you about the rings/cylinders. It will not diagnose an intake/gasket problem.

 

[HT32BSX115]

Re: Milky oil?

I finally got my 1985 OMC started... I noticed it was leaking oil so i put more in and idled to see where it was coming from, but it was still leaking and when i checked the dip-stick it was milky (water in the oil i believe). Cracked motor block is my first guess but it doesn't make sense because it has always been properly winterized... I'm just wondering what if there are some other signs of a cracked block, and if there are any other problems that lead to milky oil?
thanks
Mac

Howdy,


A cracked/rusted through or cracked block cannot be determined by compression checking cyls.

You MUST pressure check your block using compressed air.

 

[franktrav]

Re: Milky oil?

where is the oil leaking from? need mor info. is the oil fresh or old? how old? milky oil is a a sign of moisture in the crank, but doesnt mean the block is definately cracked, could be a head gasket failure,a cylinder compression check would help isolate the problem. first thing to do is pinpoint the oil leak if possible. follow up with a compression chek,and thoroughly inspect exhaust manifolds,risers, gaskets should help find the problem

 

[myu]

Re: Milky oil?

Thanks for the suggestions... The boat is in the water at the moment so i can't see the bottom of the motor and can't find the leak.. I am working on getting it out but no trailer at the moment...The oil was old don't know the last time it was changed.
thanks
Mac