Milky oil in Crankcase

[VJameslanza]

I have an Albin 40 powered by twin Lehman 135 that has run perfectly for the 4 years that we've owned it. Checking the fluid levels prior to a scheduled cruise, I found that my port engine appears to have water in the crankcase oil. The oil, which is usually a dark brown/black was almost tan, like coffee with milk. 3 weeks ago, we returned from a week long cruise during which the engine ran flawlessly. I make it a habit of checking all the fluid levels daily (trans/coolant/engine oil/diesel in Racor filters)before starting engines. Our last day out was a short 3 hour cruise home. I know that prior to the run home, the oil level/color was normal, so the water had to enter the crankcase sometime during the last 3 hours. Since the engine ran flawlessly, (No loss of oil pressure and engine ran at normal temp) I surmised that the oil cooler was the culprit, as it was the only place that the water/oil are in close proximity, so it was replaced.

I totally drained the engine oil, and replaced it with fresh oil, started the engine and ran it for almost 15 minutes (No problem starting and oil pressure was normal). I shut down the engine and the oil was once again light tan. Drained it again, and it was still showing some water. I read somewhere that you should drain the crankcase 3 times to insure all the water has been removed. I'm letting the engine sit after adding fresh oil, hoping that the oil will rise to the top, with the water at the lowest point in the crankcase. I checked it again by just draining a small amount this morning and what was drained appeared to be more 'watery' than oil. I plan on leaving the fresh oil in the crankcase and not running the engine in hope that perhaps the water would settle to the bottom of the crankcase. I read that you could also pickle an engine with diesel fuel in the crankcase. This seems like a possible course of action, as the diesel is much lighter than the straight 30w oil required. Additionally, the cost of filling and draining the crankcase numerous times is considerably less.

Opinions and feedback greatly appreciated.

 

[fgarriso]

It sounds like you do have water.
Has your coolant level drooped?
I have been told that you can fill the motor with diesel fuel. It is a light oil so it would protect the motor.

 

[DavidM]

To expand on what fgarriso asked above, a blown head gasket can let coolant get into the oil. Even worse, a cracked block can also. It doesn't take much water to turn the oil tan, so you might not even notice much of a coolant level drop. Watch it closely and see.

David

 

[fgarriso]

I didn't want to bring up a cracked head or block.

 

[sunchaser]

Suggest an oil analysis to evaluate coolant leak Vs raw water leak. Also, if your exhaust elbow geometry is incorrect a failed elbow can put raw water into the cylinders and then into engine. How old are the elbows?

 

[koliver]

There are a small number of places that can allow water to spread into the crankcase oil. The first places to check, though not in any special order: exhaust elbow, head gasket, water pump shaft seal, oil cooler tubes.
Getting the water out is not easy, as that milkshake of watery oil (oily water) clings determinedly to everything it touches. Pull the valve covers and you will find it on every surface that oil can touch.
When I had this problem, my mechanic recommended 6 to 10 oil changes before deciding no more, with that decision based on the appearance of the oil from that last change. Even then, places that require the best lubrication may still not get it, unless you can be absolutely sure there is no lingering milkshake.
Keep accurate records of all of the measures you take in your quest to achieve clean oil. Check with your insurer if your engine fails within the next year, as the original cause may still entitle you to coverage for a subsequent failure.

 

[Alisske]

Could be a head gasket. Bubbles in the overflow and loss of coolant/ hydrocarbons in fresh water system etc…..

How about oil coolers?. Whens the last time they were changed etc…. ? Seems like a good culprit since the engine ran flawlessly. I change every 2 years, but folks can change them every 3-4 years, even never.

For some reason, i think you’re gonna be ok. Replace rhe coolers if you have not. Or even plump them out of the system and run the engine with an eye on temp

I think thats your problem, but them again, I'm some guy on the internet, lmao

Good luck

 

[Cigatoo]

Suggest an oil analysis to evaluate coolant leak Vs raw water leak. Also, if your exhaust elbow geometry is incorrect a failed elbow can put raw water into the cylinders and then into engine. How old are the elbows?

I second getting an oil sample. They will determine fresh / salt / antifreeze. Now you will have a much better idea as to where to look. Please let us know the results.

 

[catalinajack]

I second getting an oil sample. They will determine fresh / salt / antifreeze. Now you will have a much better idea as to where to look. Please let us know the results.

Without knowing the character of the contamination, you will be guessing and likely chasing shadows. For example, if oil analysis shows sea water only, no anti-freeze, the more likely culprit may be your oil cooler. How old are they. CuproNickle coolers are generally good for 2,500 hours. Start simple. Coolers are simple and inexpensive. You could even swap the coolers from your other engine to rule out the coolers. Simple. No cost.

 

[OldDan1943]

There are MANY reasons for milky oil, none of the reasons for milky oil are 'good' so, get the engine checked out by a tech.

 

[Ski in NC]

Bypass the oil cooler by forming a loop with one of the hoses to both ports of the engine block. Run engine and see if water shows up at the unconnected oil cooler ports on the cooler itself.

If running light load, that engine does not need oil cooling. Ok to run for test purposes.

 

[C lectric]

Without knowing the character of the contamination, you will be guessing and likely chasing shadows. For example, if oil analysis shows sea water only, no anti-freeze, the more likely culprit may be your oil cooler. How old are they. CuproNickle coolers are generally good for 2,500 hours. Start simple. Coolers are simple and inexpensive. You could even swap the coolers from your other engine to rule out the coolers. Simple. No cost.

Second, third or whatever number. A test may help eliminate a lot of guesses.
Indicate on the form what you are looking for, Coolant or Seawater.

Ask for a phone call to speed the info back. Often these days Email works wonders too for the whole report but a phone call may still be in order.

The sooner you know where the problem may be the sooner you can better deal with the water, from what ever source.

It needs to be dealt with fairly quickly as rust will rear its ugly head if allowed to go on to long.

And pay attention to Ski in NC. He is a seriously knowledgeable mechanic and engineer.

 

[sunchaser]

If I read the OP correctly he said he replaced the oil cooler with no success.

 

[Comodave]

Yes, he said he replaced the oil cooler, but probably hasn’t changed the oil enough times yet if that was the cause.

 

[Bugaboo]

A simple pressure test of the oil cooler will rule that out other than that it’s an engine problem head gasket cracked head may be an issue with a block unlikely . I would not run the engine until the problem has been located if you damage the crank or the cam the engine will have to come out of the boat which is what you’re trying to avoid most likely head gasket , cracked head. A simple trip to the hardware store and a bicycle pump and you can test your oil cooler in a few minutes yourself Or take it off and have it tested

 

[Island Cessna]

A radiator pressure tester will quickly determine if the leak is in the coolant system. I would not test run until it passed this test as anti freeze in oil is hard on bearings, and coolant leaking into cylinders from head gasket or cracked head, block, etc can cause hydraulic lock and bent rod.
If it passes this test move on to raw water system.
When chasing coolant or raw water internal leaks it is always a good idea to bar the engine over by hand 2 turns minimum before starting to be sure no water is in the cylinders to cause hydraulic lock.

 

[SteveK]

I will add torque the head. makes sure the head gasket is compressed to spec.

 

[OldDan1943]

I will add torque the head. makes sure the head gasket is compressed to spec.

I was taught in the Navy, to re torque, each bolt must be loosened and then torqued to a specified amount, in a pattern, a little at a time. The reason to loosen first is to make sure the rust or paint is not hold the bolt.

 

[kchace]

I will add torque the head. makes sure the head gasket is compressed to spec.

Per the manual, Lehman 135's are not supposed to be re-torqued - ever.

 

[OldDan1943]

Per the manual, Lehman 135's are not supposed to be re-torqued - ever.

That satisfy that, never ever

 

[rgano]

Pretty much EVERYTHING that could result in water in the oil has been mentioned here, and I would guess the source of water have been covered therein. As to ridding the engine of the last bit of water, I remember being told that submerged engine recovery, provided it was done within 24 hours, consisted of dumping the sump contents and filling it with diesel before turning the engine over with an air-driven drill attached to the crank pulley with the injectors pulled followed by another dump and another diesel refill and dump before putting the injectors back in and three oil changes with warming of the engine by running it between changes.

In your search for causes, you might want to disconnect any coolant lines running to the water heater and make sure nothing comes back from the heater with water pressure on. Far fetched as a possibility, but, hey, it's a boat.

 

[SteveK]

Per the manual, Lehman 135's are not supposed to be re-torqued - ever.

I heard that before I suggested it. Who says it was torqued correctly, or one or two bolts did not stretch from overheating. I really do not understand never having to torque in the manual.

Some people change their oil even when the experts testing it say it is still good to use. And BMW does not have a dipstick because the computer is smart enough to know the oil level.

So we evolve.

 

[FF]

Most boats do not carry enough lube oil on board to flush an engine.

Diesel with a quart of lube oil, works for a flush or two before using real lube oil.

A min. of idle engine operation will move the diesel into the water.

There need not be an oil filter in the housing while flushing.

 

[diver dave]

Bio-diesel holds far more water than petro-diesel. If, big IF, I was looking for a diesel flush to absorb water, I might pick bio diesel. Several orders of magnitude more water carrying ability before saturation. And, warmer the better.

There is a danger though. A mix of bio and petro diesel has a poor effect.

Of course, the really bad news is here:

https://www.donaldson.com/en-us/bulk-fluid-storage/technical-articles/water-enemy-diesel-engines/

 

[KnotYet]

Bio-diesel holds far more water than petro-diesel. If, big IF, I was looking for a diesel flush to absorb water, I might pick bio diesel. Several orders of magnitude more water carrying ability before saturation. And, warmer the better.

There is a danger though. A mix of bio and petro diesel has a poor effect.

Of course, the really bad news is here:

https://www.donaldson.com/en-us/bulk-fluid-storage/technical-articles/water-enemy-diesel-engines/

Regarding the life expectancy graph you posted,
which if any bearings in a FL are rolling element?

 

[diver dave]

Not the shell bearings. Perhaps the small end rod needle /rollers. Not aware of others.

 

[porman]

Many engines, not just diesels, have stretch bolts in various places, not just the cylinder head. These bolts cannot be re-torqued or re-used. Know what you have first. (retired mechanic with 40 years experience)

 

[Alisske]

If I read the OP correctly he said he replaced the oil cooler with no success.

Yup, lol. he sorta snuck that in there, lol. My bad

 

[Mischief]

Check for oil contamination of the coolant, also pick up a test strip kit from napa and check the coolant for combustion gasses. Get an oil sample tested.

 

[VJameslanza]

Thank you all for all the good advice. It's one of the main reasons that we join the Trawler Forum, for the wealth of information of the members.

I have sent an oil sample to Blackstone, and am awaiting results, which will dictate the next steps that I take.

I have taken small samples of the last oil change and noted that it was 'watery' and not 'coffee with milk'. I am not going to change the oil till Blackstone results

I plan to 'wash' the crankcase with diesel fuel (with H20 dispersal agent added) several times, then fill crankcase with inexpensive oil before running/draining and using Rotella T1 30w oil (recommended).

It's difficult to type this reply with my fingers crossed, but that's what I'm doing. Again thanks to all!
Jim