Water in motor oil

[OMC73]

Well I think I'm screwed. I checked my oil in my omc 120 today and it was milky. Any possibility it is a simple thing? I recently did my impeller in the drive and ran the engine a minute with the water supply line off the exhaust to verify it was pumping water. Not sure if that would matter.

 

[southkogs]

First time you've noticed it? After owning the boat a while? If it's running right otherwise, I think I would change the oil and run it on muffs a bit and check the oil again.

 

[bruceb58]

Could easily be the manifold riser joint leaking too.

Explain your statement " ran the engine a minute with the water supply line off the exhaust".

Are you saying you used muffs?

 

[Bondo]

I checked my oil in my omc 120 today and it was milky.

Ayuh,..... Is the Level to high,..??

Could just be condensation if the oil Level ain't risin' as the motor runs,...

 

[OMC73]

Thanks for the replies. This has been a project boat (73 seaswirl tri-hull omc 120 hp) that I have owned a few months. The original​ motor was shot. I found a used omc 120 from a reputable boat repair shop and had it installed. I heard it run with hose water directly attached to the water inlet on exhaust elbow and no water in oil.

I get it home start it up using the water flushing attachment on the out drive trunnion cap. Didn't notice water in the oil. A couple weeks go by, I have time and money, so I replace the impeller pump in outdrive. Start it up with the drive submerged in water to test the impeller. It worked so I shut it down. I needed a new battery so it sat for a couple weeks until payday. Last night working on the boat and checked the oil discovering the water. I would estimate the oil level is up by about a quart. I hope I answered all of the questions.

 

[OMC73]

Could easily be the manifold riser joint leaking too.

Explain your statement " ran the engine a minute with the water supply line off the exhaust".

Are you saying you used muffs?

I submerged the drive in water and took the hose off of the exhaust elbow to see if water was being pumped via the impeller. I was not using muffs. What is the manifold riser joint?

 

[bruceb58]

What is the manifold riser joint?

It's the elbow that connects to the manifold...usually. What are you working on..year?

 

[OMC73]

The boat is a 73, the OMC 120hp motor I'm not sure what year. The model # is cufm19ex, serial #W160738 and it is painted grey vs. the old motor being blue. Not sure if that matters.

 

[bruceb58]

There is a large elbow that attaches to the exhaust manifold. If the joint here fails or the manifold/and or riser corrodes over time especially when used in salt water, you can get water into your engine.

I would pull it off and inspect. You will need to replace the gasket before you reinstall. You want to see if the surface and the wall thickness is still adequate.

Is the boat used in salt water ever?

 

[OMC73]

Not sure of the history of the boat and motor in regards to being in salt water. I will pull the riser off and inspect.

 

[bruceb58]

I just re read your previous post read where your said your oil is up a quart. Usually, if it's up that much higher, it's not due to a riser failing. That is usually due to a cracked block. I would be pressure testing the block

 

[OMC73]

Update:
Drained the oil, hooked up the garden hose and left the oil drain plug out. Ran the water and after a few minutes, a very slow drip developed out of the drain plug hole. Also found a drip on the bottom of the intake directly below the carb on the edge closest to the block. I've been told if the block is cracked you will see rust streaks on the port side of the block. I do not see that condition at this time. Could there be an internal crack?

 

[Bondo]

Could there be an internal crack?

Ayuh,.... Sure can,... In my experiences, the most common spots for that block to crack are,.....

Along just under the head at the top of the block, on the port side, up under the manifolds,...
Or,...
Along the inside of the oil cavity, behind the block's drain plug,....

Rust is usually, but not always seen,....

Isolate the block's coolin' passages, 'n pressurize with air,... 'bout 15 psi,...
You'll Hear the leak, follow the sound to the crack,....

 

[OMC73]

I called the shop I bought the motor from and I'm getting my money back so I'm back to square one on this project.