Extracting emulsified oil from the engine

[richardsnowstar]

Thanks for all the advice, I am learning a lot.

The water pump has drain slots to stop contamination and these appear to be only partly blocked.

The other concern is that the engine was smoking (seperate thread) before I noticed the emulsified oil so I am concerned now about the head gasket.

While sourcing replacement parts a very helpful supplier suggested removing the dipstick tube and using a larger suction tube with the vacuum pump. This seems like a very good idea that I thought I would share. I am sre this will help my problem extracting the oil.

The engine is raw water cooled.

Another suggestion I have had is to pressurize the water sytem with air (at low pressure) to see if this highlights the problem.

 

[Feneris]

I had a similar problem on a car, in this case it was oil in the water cooling system, which had emulsified. I changed the engine, but was stuck with the emulsion in the radiator, pipes, heater matrix etc. I used lots of cold water to flush it through, and pulled rags through the pipes. I then re ran the engine, which over heated soon afterwards. On disassembly, the water pump was clogged with the emulsion (which had travelled from elsewhere in the system) , which despite it spinning at high rpm with the engine, wasn't moved through, hence the lack of circulation. The emulsion seemed to stick to anything and let water flow past it. Whether this could happen here, I don't know, but a lack of oil pumped to the cylinder head cams etc would not be good.

 

[Avocet]

The engine is raw water cooled.

Another suggestion I have had is to pressurize the water sytem with air (at low pressure) to see if this highlights the problem.

OK, if it's raw water cooled, then it's pretty certain to be seawater. That's not good. Pressurising the cooling system will be difficult because it is also part of the exhaust system. The raw water gets dumped into there when it's been round the engine. If your problem is NOT the raw water pump, there aren't any easy options, I'm afraid. I think if it was my engine, I'd check the obvious things (like the vent at the top of the anti-syphon loop for blockages, and maybe have a look at the injection point in the exhaust manifold or elbow. Assuming all was as it should be, I'd probably just try and run the engine again (on cheap oil) and see if the problem has gone away. If not, it looks like it could be some sort of breach between the cooling system and the crankcase. This could be rust or a gasket / seal not working. It could also be water going back into the cylinder on shut-down, for some reason, and that might have done other damage. You might be able to blank off the water injection point into the exhaust and pressurise it then, but it's difficult without knowing the engine. If the leak is into a combustion chamber, you're likely to get some slow loss of pressure anyway, as it gets past the piston rings and into the crankcase.

 

[LittleShip]

Only scanned the pages so ....

It may be that the oil cooler has started to leak and this will find it's way back into the sump.

As others have said,

1 Warm with fan heater and remove emulsified oil and change filter.
2 Use a flushing oil.
3 Refill with a reasonable oil and change filter.
4 Run engine until fully warmed up. Any water left will evaporate off.
5 Drain change filter and refill with standard oil.

Short term you should have no damage to the engine by having water intrusion.

Tom

 

[richardsnowstar]

As a follow up to this thread as the OP......

The engine suffered broken valve springs plus some other corrosion damage as a result of the water in the oil. Despite flushing the oil 3 times to remove the water I have discovered that the remaining moisture evaporates upwards and condenses in the rocker cover and other high points of the engine. In my case this included the hand crank casing. So as well as the oil changes (including flushing with 50% diesel and 50% oil) I should have wiped out the inside of the rocker cover and other parts to remove the residual moisture. This has been a very expensive lesson to learn.

 

[Avocet]

OUCH! Thanks for the heads-up. Seems it has happened to a few other people on this thread, so worth bearing in mind.

 

[cryan]

Don't put diesel in your sump! The failures above (post 10) could well be due to diesel as opposed to the water.

There is only really two options:
1) Drop the sump out completely and physically clean the inside of the engine followed by repeated oil changes until all signs of moisture are gone.

2) Find someone who has a portable oil purifier or coalescing filter machine to circulate your oil. This would require modification to the oil system (probably cooler pipes) to allow the machine to tap into the system. This option whilst common in commercial use is likely to be too awkward and expensive for a leisure boater.

 

[cryan]

Sorry only just noticed age of this post.