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Here I sit in a marina in France BR's engine in pieces. Why, you ask? Salts in the oil.

Prior to the trans-lant last summer I re-powered the boat. Out went the 18 yr old 55 hp Nanni, in came the new 110 hp Yanmar. (Note the boat's designer indicated we needed at least 90 hp, so the first owner obviously underpowered her.)

As we will sell the boat sometime in the next 5 yrs or so I decided to have an oil analysis done with each oil change. I took a sample at the 50 hr oil change in Newfoundland, and another when I laid up the boat in Scotland last September at 280 hrs. I forgot to take the samples home with me and the first opportunity to send them to the lab was in the luggage of a departing crew member several weeks ago.

Lab reports came back: first oil sample had small amounts of sodium and potassium in the oil. The lab was curious. The second sample (taken at 280 hrs) showed a very large increase in the amount of sodium (5200 ppm) and a similar increase in the potassium. Lab said -- no doubt something is leaking into the oil. They said it could be seawater, or it could be coolant. "Find the leak" was their recommendation. Salts in the oil were causing accelerated wear of critical bits of the engine -- and the metal content of the oil samples was also well above normal.

I'll stop here for an important digression: without the oil analysis I would have never known this was going on. The engine runs perfectly, aside from a bit of soot on the transom. I would have continued motoring along (when not sailing) fat, dumb and happy and, because I plan to sell the boat, it would have been the next guy's problem because the excessive wear of bearings, etc. would probably not shown up as a real problem for a while. But I do have the oil analysis and so it's my problem. :(

So, the question is what to do?

First step was to call the Yanmar guy here in Brest, France. He's a nice man in his late 50's (that's good -- means he's experienced), and he speaks some English (that's also good because I have only high school French and a copy of "French for Cruisers").

He comes aboard last week and the first thing he does is take another oil sample. His examination of the oil on the dip stick and inside the valve cover suggests to him that it's not water. He said, "The oil is beautiful". First time I've heard someone call dirty 150 hr engine oil "beautiful", but this is France and things are different here.

So far we have removed the oil cooler and pressure tested it on the bench at 80 deg C. It's good, no leak there. The oil analysis requested last week came back today and we continue to have sodium and potassium at elevated levels. So there's a leak somewhere.

The question I have for the gathered mechanical cognoscenti is what course of action do you think we should follow from here? What are the potential sources of a leak of either seawater (minimal probability) or coolant (likely) leaking into the oil.

All though I have confidence in Philippe, our local Yanmar guy, your sage advice will be welcome.

I will conclude by saying that it's true -- cruising is defined as working on your boat in exotic places. While Brest isn't exactly "exotic" the food is very good, the cheap wine very good, the bread excellent and the cheese very smelly. What more could you ask for? :D

PS -- I forgot to mention: we had an overheating incident at 10 hours when the main alternator belt came off while motorsailing. Engine was shut down immediately (like within 10-15 seconds of the alarm), but the temperature gauge indicated 250 deg F / 120 deg C. Motor has worked flawlessly ever since. And I should add, we have had no over-cranking incidents -- the engine starts immediately, as a very expensive Yanmar should.
 

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I am also a believer in oil analysis however most of the ones I have used are detailed enough to distinguish between saltwater or coolant intrusion. The company I use most often is Blackstone Labs. After checking all of the basics on your engine I would look at sending your oil somewhere else for a more detailed analysis. I do agree that it is almost certainly coolant though. If it were saltwater you would see mostly sodium but not much potassium. How are your phosphorus and boron numbers? These are also indicators of coolant leaks. There are a couple other elements too but I can't remember them off the top of my head.
 

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It doesnt matter how the oil 'looks' as when it gets hot it 'boils' out the water leaving the salts behind.

In order Id check the following:
1. Pin hole leak in the exhaust manifold ... causing water to be sucked into a combustion chamber after shutdown.
2. Blown head gasket - ditto above + engine pressure leak down test (leaking into the crankcase, especially) .
3. cracked warped cylinder head
4. cracked block -- fluorescing dye placed into cooling fresh water now 'showing up' / fluorescing in crankcase,
5. cracked turbo oil heat exchanger if you have one.

Pressure (Hold) testing each component in situ or removed and disassembled is the only way to go - IMHO
You can narrow down those choices by adding fluorescing dye to the fresh water side and then examining oil, cooling water under 'black light' to make the oil fluoresce or alternate dye to check for CO in the cooling water, or crankcase oil.
Choose the correct fluorescing dye for the specific area of the engine youre inspecting.
 

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Perhaps I missed it, but I assume the references to "coolant" mean this engine has a heat exchanger and closed cooling system. In which case, it would be consuming coolant and that system would be showing a low coolant level, if that's what was being sucked into the oil. No?

So if there's no coolant being consumed, seawater as the salt source might be the first place to look at. Or as suggested try a second lab to see if they are more specific. Is there any chance the salt is simply from airborne spray being ingested?

Rich's mention of UV dyes is also good, they are terribly under-utilized but very good for diagnostics.
 

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blackstone is the standard for oil testing...might try them as a second opinion as stated...

to me you have all the possible causes already mentioned here...its an obvious leak into the oil from one or 2 sources...I have my mind set on coolant leak from the exhaust manifold.

you already accepted you overheated...all it takes is one time...even if it starts fine and works fine after it doesnt mean it wasnt enough to blow a little head gasket or pinhole a passage, etc...

btw! of course the yanmar rep is going to say the oil is beatiful...deny deny deny until you have no other option is what he is being told to do or thinking.

good luck
 
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"btw! of course the yanmar rep is going to say the oil is beatiful..."

Was it not Senior Enzo Ferrari himself who said "The aesthetic beauty of oil should not be mistaken for superior lubricity." ??

In France, these things matter. In the US, we rarely take the time to admire the wide range of colors and scents, the tingle on the fingertips and tongue, of truly fine motor oils. I do not think this should be overly held against us, as we are, however slowly, coming to appreciate the difference between extra virgin olive oil, and lard.

One thing at a time, eh?
 

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For my 2 cents worth, I also would look to the overheating incident for your problem.
I'm not too sure about Yanmars, but some diesels require a re-torquing of the head after "break in"? Perhaps if this was required and not done, in conjunction with the overheating incident.............?
 
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"btw! of course the yanmar rep is going to say the oil is beatiful..."

Was it not Senior Enzo Ferrari himself who said "The aesthetic beauty of oil should not be mistaken for superior lubricity." ??

In France, these things matter. In the US, we rarely take the time to admire the wide range of colors and scents, the tingle on the fingertips and tongue, of truly fine motor oils. I do not think this should be overly held against us, as we are, however slowly, coming to appreciate the difference between extra virgin olive oil, and lard.

One thing at a time, eh?
VERY true...

I did this every ride on my old air cooled motorcycle...you can tell a lot from smell, taste, and feel....

however it would take quite the gourmand in france to tell by look only wether the oil has potassium or coolant or salt or whatever...

:)
 

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Discussion Starter #10
I am also a believer in oil analysis however most of the ones I have used are detailed enough to distinguish between saltwater or coolant intrusion. The company I use most often is Blackstone Labs. After checking all of the basics on your engine I would look at sending your oil somewhere else for a more detailed analysis. I do agree that it is almost certainly coolant though. If it were saltwater you would see mostly sodium but not much potassium. How are your phosphorus and boron numbers? These are also indicators of coolant leaks. There are a couple other elements too but I can't remember them off the top of my head.
Blackstone did the analysis and leans toward coolant, but wasn't 100% sure.
 

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Discussion Starter #11
Oil analysis came back today with ongoing sodium intrusion. French lab thinks it's a coolant leak. This seems to be confirmed by the pressure test we did today on the cooling system. Results of that are: pressure starts off at 1 bar, and drops fairly steadily over 1 min. or so to 0.75 bar and then it stabilizes. This suggests a small leak that gets worse under pressure, n'est-ce pas?

We're waiting on a confirmation of delivery go the gasket set which we ordered yesterday. First guess by the supplier is Monday, maybe Tuesday next week. I could fly to Holland and pick them up for less than what another week on the dock will cost....I just may do that.

The mechanic is reluctantly saying that it's "grand chose" (big stuff) and may take 4-5 days I'd wrench work to replace the exhaust and head gaskets. Lot's of stuff has to come off to get to the problem.

If this goes on too long I may need to think about moving on across Biscay while the weather is good.

Need some input from the obviously knowledgeable responders above: Will frequent oil changes, say every 50 hrs or so minimize the damage until we reach another long term stopping point? Or should I suck it up and fix it here and develop cruise plan B?
 

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I would be inclined to get it fixed before moving on. At least where you are you are making significant progress towards fixing the problem.
 

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now! its such a new engine...now if it were really old and on its last legs I would say some egg whites iin the heat exchanger for the mean time and very frequent oil changes...

dont risk destroying such a nice and expensive engine...

GOOD LUCK!
 

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Frequent oil changes will certainly help. I think the rate at which the damage will occur is greatly overstated. I had an old Honda in college that had a bad head gasket. It was a $500 car with 280K miles on it. I made the decision that it wasn't worth the time or expense to fix it and I was just going to drive it until it died. I filled the coolant up once a week and changed the oil when it got too milky (my standards were very low.) I expected the car to make it a couple months or so. I ended up driving it 2 years and another 50K miles. Got a real job and got tired of the car so I sold it for what I paid for it. It still ran like a top and I wouldn't have hesitated to drive it across the country. A year later I was still seeing it around town. My leak was significantly worse than yours and my maintenance was significantly worse than yours. I think you will be fine. Quit worrying and go out and enjoy your boat.
 

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Your leak sounds to me to be very minor. If you aren't noticing a drop in coolant levels, the oil level isn't increasing, and the oil isn't turning milky you have a VERY minor leak. I think this thread might be turning a molehill into a mountain. I am not saying to ignore this forever but I don't think it is an emergency that needs to be dealt with immediately. It can wait until your dockage situation improves.
 

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I agree completely, the issue is this isnt an old honda anvil its a very expensive yanmar that is near new...

yes I bet the damage is is so minor its not even registerable on the oil level or coolant check

this would be a great question to ask

is the coolant dropping any every oil change and is the oil milky and or rising at each oil change, if so what hours between oil changes?

very frequent say every 10 hours or so for the next months will be enough to prevent any further damage...you can also baby the engine at low rpm(even though this is not good for most diesel as you will soot up) and then when circumstances allow you do the gasket change and fix properly

you could also simply not use the engine(sail or hip tow) till you get to a place where you can get better parts stock and mechanics or whatever you feel like.

lastly and I agree with krazz here, if everyone with an inboard diesel did blackstone lab oil anyalis on their engines even more people would never ever ever leave the dock EVER! plenty of old ratty engines with issues that last forever.
 
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I didnt see the part about the 'over-heat' incident.

Consider:
The overheating incieent would be my highest index of suspicion .... the stretching of the cylinder head bolting due to the extra heat and the relaxation of the 'clamping pressure' that the head bolting provides - blown or leaking head gasket AND/OR heat stretched head bolts.

This is easy to analyze without a cylinder head 'rip down' - go to an auto supply shop that caters to 'auto racers', get some of the fluorescent dyes that are used to detect carbon monoxide in the cooling water. When/IF CO gets into the cooling water the dye will fluoresce when 'black light' is shone into the water.

Do this first before you re-torque the head, and then re-torqueing with 30wt oil to lubricate the studs and re-torque SEVERAL times in succession so that you get correct torque.

Then repeat with the dye AFTER changing the cooling water and repeat with the fluorescing dye analysis to see if the re-torqueing was successful .... if not, replace the head gasket (which is probably leaking between an oil gallery supply port to the overhead valves and a cooling port within the head gasket ... plus into a cylinder).
 

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I think you have a problem with your alarm. if it didn't go off till 245 or 250 that's way to hot. I have 2 temp alarms on my boat one is factory and I don't know what temp it trips at and the other I installed to sound at 200 degrees F. This gives me a little time to get the boat out of danger before shutting off. I wouldn't let an engine go over 212 F myself.
 

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If it is salt instead of coolant & the exhaust manifold is salt water cooled, the manifold may be leaking salt water into the ports? If you are not losing any coolant the only other source I can think of is salt water in the fuel that is getting past the filter/separator? That may be a stretch, however. It would be interesting to know what you find.

Paul T
 

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If it is salt instead of coolant & the exhaust manifold is salt water cooled, the manifold may be leaking salt water into the ports? If you are not losing any coolant the only other source I can think of is salt water in the fuel that is getting past the filter/separator? That may be a stretch, however. It would be interesting to know what you find.

Paul T
PIN-HOLE between the gas side and the water side of the ex. manifold .... quite common in engines that have been in service for awhile, and especially in engines that are 'drained' of cooling water for long term layup / winter layup.
 
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