Milky Oil

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Hey RT, Hey Ross,

Sorry....the fact that it is a freshwater boat fell out of my mind somewhere along the thread!

-Greg
 
RossWilson said:
Actually, RTF, the mechanic did replace the oil and filter same day as we discovered the cafe oil. And the service manager recommended having the oil tested (at a cost of $99), which I thence ordered. I just don't recall if he started the genny immediately afterward. Maybe he did, but it didn't run for very long.
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The usual protocol for changing the oil and filter requires running long enough to fill the filter before checking fill level to make sure the engine has the right amount of oil, so it should have at least been run 5 minutes and all oil passages that had the cafe au lait would get that replaced with new oil. The dipstick should then give you a good indication of what is in all of the oil passages.
From now till you get the analysis won't make a significant amount of difference, so I would wait and look for either antifreeze or salt water in the report. Once you know that, you are closer to knowing the source and can plan your next step.
 
Thanks Keith. As I said, the oil analysis reported a high amount of H2O, but no glycol. And my boat has always been a fresh-water vessel.


I'm confident that, since it's standard procedure, the techie ran the genny for awhile after installing the new oil and filter. Nevertheless, I plan a drive up to have a peek at the oil again myself.
 
Greetings,
Mr. RW. Some people may not know where Oakville is much less Ontario or Canada...


giphy.webp





Present company excepted, of course!
 
Hey Ross,

Out of curiosity, is there glycol in your freshwater loop? Its absence in the oil, given the presence of large amounts of water, could still be a clue as to the source.

Cheers!
-Greg
 
IF the oil is removed from the engine with a low point plug , a couple of changes will help .

I would use a hand pump and hose down the dip stick hole to remove the water in the very bottom of the pan.
 
RT Firefly said:
Greetings,
Mr. RW. Some people may not know where Oakville is much less Ontario or Canada...


giphy.webp





Present company excepted, of course!
Click to expand...
Sadly, you're probably correct, RT. But all you 'south-of-49ers' should consider boating our pristine waterways. People come from around the world to travel Georgian Bay and the North Channel. :)
 
gkesden said:
Hey Ross,

Out of curiosity, is there glycol in your freshwater loop? Its absence in the oil, given the presence of large amounts of water, could still be a clue as to the source.

Cheers!
-Greg
Click to expand...
Thanks, Greg, for your comment. The boat has spent every winter in heated storage. So, though I've not tested it, I'd not expect any glycol in the cooling system.
 
FF said:
IF the oil is removed from the engine with a low point plug , a couple of changes will help .

I would use a hand pump and hose down the dip stick hole to remove the water in the very bottom of the pan.
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Sorry FF, but I don't follow your proposal. I presume you mean a spark plug low in the engine? But how could 'hosing down the dipstick hole' remove water?
 
RossWilson said:
Sadly, you're probably correct, RT. But all you 'south-of-49ers' should consider boating our pristine waterways. People come from around the world to travel Georgian Bay and the North Channel. :)
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Georgian Bay, isn't there a water dragon lives?
 
Many of these little engines the drain hose comes out of the side of the oil pan, which really does not get all the water sitting in the bottom. On some a little sucker tube can hit the bottom of the pan and then you get almost all of it out.

That's what FF was referring to.

Also look in the oil fill hole in the rocker cover and see if there is moisture beaded up on the rocker arms and springs. That is no bueno.
 
RossWilson said:
Sadly, you're probably correct, RT. But all you 'south-of-49ers' should consider boating our pristine waterways. People come from around the world to travel Georgian Bay and the North Channel. :)
Click to expand...

Boy oh boy are you right about Georgian Bay beauty!!! 1992 was a great year there.
 
Ski in NC said:
Many of these little engines the drain hose comes out of the side of the oil pan, which really does not get all the water sitting in the bottom. On some a little sucker tube can hit the bottom of the pan and then you get almost all of it out.

That's what FF was referring to.

Also look in the oil fill hole in the rocker cover and see if there is moisture beaded up on the rocker arms and springs. That is no bueno.
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I understand. Thanks ski.
 
Ski in NC said:
Yea, you don't want that engine sitting over the winter with water in it. Good chance you will be buying an engine in the spring.

What generator model/brand?

I'd get the yard to back the boat out of the shed to where you can do a proper job of drying out the engine running it loaded on garden hose.

If that is too much trouble, might be able to fill whole engine with oil or diesel. Maybe take rocker cover off and dry out that area, that's where condensation tends to collect.
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Anytime I found milky oil it was standard practice to drain, fill with diesel, drain and add new oil and filter. Any decent mechanic should have a way to pressure test the fresh water side. How old is the riser?
 
Hey Ross,

RossWilson said:
Thanks, Greg, for your comment. The boat has spent every winter in heated storage. So, though I've not tested it, I'd not expect any glycol in the cooling system.
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The boat has a closed freshwater loop and heat exchanger?

I know water has a higher specific heat capacity than antifreeze (ethylene and propylene glycol), so it cools better. But, even in Florida (and So Cal before), I've always used an anti-freeze/water mix. I guess I figured there'd be anti-corrosion and pH-balance additives that would help keep the cooling loop clean and corrosion-free.

I'm not saying what I do is right, or that you should do it, too. It is just what I was taught to do -- and sort of thought everyone did.
 
Intake hose in a bucket and garden hose in bucket, turn on hose and regulate to what the engine demand is run genny till hot and change oil and filter. re run engine under load and check oil when engine has warmed again. Ensure hose and exhaust water going somewhere safe, you can always put some schedule 40 2"pvc or similar to your hull exhaust to carry fumes and water etc out of the building. PVC repair rubber connector from home depots only a couple of bucks.
 
dsharp said:
Anytime I found milky oil it was standard practice to drain, fill with diesel, drain and add new oil and filter. Any decent mechanic should have a way to pressure test the fresh water side. How old is the riser?
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I agree that it should be possible for a mechanic to perform such a task. Perhaps it would be challenging since the boat is in the back corner of a very large heated building - with numerous other big boats on blocks surrounding her. I plan to drive up and investigate further, now that I have a better idea of what I'm talking about, thanks to everyone here.



If you mean the exhaust riser, I believe it's original 2006 equipment.
 
gkesden said:
Hey Ross,



The boat has a closed freshwater loop and heat exchanger?

I know water has a higher specific heat capacity than antifreeze (ethylene and propylene glycol), so it cools better. But, even in Florida (and So Cal before), I've always used an anti-freeze/water mix. I guess I figured there'd be anti-corrosion and pH-balance additives that would help keep the cooling loop clean and corrosion-free.

I'm not saying what I do is right, or that you should do it, too. It is just what I was taught to do -- and sort of thought everyone did.
Click to expand...
Not sure, Greg, but I believe the Kohler 8kn diesel generator has a closed cooling system with heat exchanger. I know the main Yanmar engines are configured this way. But the Kohler?
 
RT Firefly said:
Greetings,
Mr. OD. I've never heard of any "creatures" in Georgian Bay although I am not very familiar with Lake Huron lore. You may be thinking of the Ogopogo that dwells in lake Okanagan in British Columbia.



Here's "proof"! https://www.news.com.au/technology/...s/news-story/c81bf6fd15b59a2e4e3e845c99206584
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https://youtu.be/85hoQeXLmVw?t=14

Seems our Lake Okanagan Ogopogo has a sibling in the desert.

Seriously though,
I have never seen any engine filled with just water. Manufacturers ALWAYS put in a 50% mix of Anti Freeze and water, as there are corrosion inhibitors in the AF. Your test results showing no AF now prove that your milky oil is from a water leak, so look at exhaust riser, water pump seals, Oil cooler leaks, but not at Head Gasket or other sources connected to the in-engine cooling.
 
MacPhid said:
Ross,

I’ve been boating (and winterizing) on Georgian Bay for a number of years. Once our boat is hauled, I run the generator with a winterization kit connected and fed into the raw water strainer.

https://www.amazon.ca/Camco-65501-Yourself-Boat-Winterizer/dp/B0000AXQU2

I fill the 20 ltr jug with pink RV antifreeze and the start the engine. Open the boiler valve on the jug and it’s fed through the raw water circuit. It will run for 2 or 3 minutes on 20 ltrs.
This would allow you to run the engine without the need for a water supply in the storage facility. You could then change the oil and filter one more time for peace of mind over the winter. If the yard won’t allow you to run it yourself, get them to do it.
I winterize both my main engines and the generator this way every year. Not ideal for oil change as the generator doesn’t get hot, but at least you’ll have the peace of mind knowing there is a second change with fresh oil in it for the winter.

James
Click to expand...
Thanks, James. That practice sounds, well, sound. In theory, though, stowing my boat in a heated building for the winter should alleviate me of the need to fully winterize my engines. I'm told that all I have to treat is the septic and fresh water systems, that is empty and shock them. Is this not your view too?
 
koliver said:
https://youtu.be/85hoQeXLmVw?t=14

Seems our Lake Okanagan Ogopogo has a sibling in the desert.

Seriously though,
I have never seen any engine filled with just water. Manufacturers ALWAYS put in a 50% mix of Anti Freeze and water, as there are corrosion inhibitors in the AF. Your test results showing no AF now prove that your milky oil is from a water leak, so look at exhaust riser, water pump seals, Oil cooler leaks, but not at Head Gasket or other sources connected to the in-engine cooling.
Click to expand...
That makes sense, Keith. I plan a trip up to visit the marina very soon to investigate further.
 
The idea of extracting most of the oil/water through the dipstick using a hand "oil" pump and small hose is a good one as the water will eventually settle to the bottom. That should help remove the water as long as you don't still have a "leak".
Otherwise, great advice to change the oil and filter a few times to "clean it out".
 
firehoser75 said:
The idea of extracting most of the oil/water through the dipstick using a hand "oil" pump and small hose is a good one as the water will eventually settle to the bottom. That should help remove the water as long as you don't still have a "leak".
Otherwise, great advice to change the oil and filter a few times to "clean it out".
Click to expand...
My boat is equipped with an oil extraction system. Thus, most of the oil can be removed easily. But perhaps the remnants of the oil, and water, if any at the bottom of the pan, could be removed using a hand pump. I'll put it into practice. Thanks Tom.
 
Hey Ross,

My Kohler 6EOD is a 6KW diesel and it is cooled with a closed loop and heat exchanger versus directly with raw water. So, I am betting yours is the same, even if you are in fresh water. And, if that is the case, I'm really betting on it being a xyz-glycol/water mix. Doing otherwise would just be unusual (and, as I mentioned, in my world, worthy of a cooling system flush and correction).

On your way to the boat what I'd recommend you stop by an auto parts store or Wal-Mart and get an antifreeze tester. They usually cost $4-$9. Something like this:
-- https://www.walmart.com/ip/TESTER-COOLANT-PRESTONE/16817506

Then, once on the boat, I'd pull the cap off of the cooling header tank and look at the inside of the cap and the inside of the neck. Then, I'd put my finger or the corner of a clean shop towel into the tank to get into the fluid. See if there is any oily or milky residue. Oil is lighter than water, so if it gets into the coolant, it'll find its way to the top. Maybe if coolant was getting into the oil, oil was getting into the coolant. If you find oil in the coolant, well, that'll be a big hint (the opposite doesn't disprove anything, though).

The next thing I'd do is give the coolant a good smell. Does it smell like water or antifreeze (or antifree-water mix)? After that, I'd check the coolant with the tester. It basically measures the density of the fluid and can give you a good idea if it is water, coolant, or a mix. It'll also let you see the color. Is it clear like water? Deeply colored like antifreeze? Or lightly colored like a mix?

With luck, your nose, your eyes, and the needle will give a similar (or, at the least, not inconsistent) indication. If you want to be a scientist, you can even send a coolant sample out to be tested, just like the oil. Ultimately, if you've got glycol in the coolant (And, I think you really should), but not in the oil -- I really don't think the coolant system is leaking into the oil.

If you find that your cooling system truly has only water, that's not much help in narrowing things down. So, for the sake of conversation (and, because I think it more likely), let's assume that the cooling system has some glycol -- and your oil sample shows none (as I understand is the case). The question becomes, how can raw water get into the oil?

-- One possibility is that it was over-cranked when starting. In a marine generator if the engine won't start and one keeps trying, the raw water pump can push water through the heat exchanger into the exhaust, and then let it fall back into the motor This is actually a pretty dangerous condition, because it can get into the cylinder and cause a hydrolock with damage like bend rods or much worse. Basically, unlike a fuel-air mix, the cylinders can't compress water, so if the generator starts and it tries, things bend and break. (If a genset won't start after a short attempt, close the intake seacock, until it does...)

-- Another situation that can cause a hydrolock in an aft-exhaust genset is cruising without the genset running. If one backs down or gets hit with following seas, without the positive pressure from exhaust, it is possible for water to get forced up the exhaust and for the same thing to happen. (This is why I always cruise with my genset on and had the exhaust and elbow raised higher.) The same can happen with side exhaust from excessive rocking side-to-side when moored or anchored. (In a badly designed exhaust, shared with the main(s), the main(s)'s exhaust can also get pushed backward into the genset).

-- Another possibility is that a human was intending to top off the coolant -- and dumped it into the valve cover cap, instead. It sounds crazy. But, depending upon access, it may be easier to do than it seems. They are often similar-sized push-and-twist caps on top.

-- If the generator has an oil cooler, it could be leaking. I think it unlikely. My last generator didn't have one. And, on my current generator it is a rarely installed option. If you can tell me the model of your generator, I can see if I can find the service or parts manual and look.


As you can probably tell from some of my posts, I am the type that likes to collect all the data first. So, although I'd change that oil and filter repeatedly right away. I'd also have sent it off for analysis (as you did), analyze the coolant (sending it out, if needed), think carefully about the usage and service history for clues (hard start? following seas while off? Recent fill with coolant?) and look carefully for signs of raw water backing up, rust, etc.

At any rate, if you post the model of generator, I can google around and see if I can find the service and/or parts manuals, and see if there is likely an oil cooler or not.

But, I think the absence of glycol in the oil will turn out to be a big clue.

Cheers!
-Greg
 
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