[hellosailor]

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.

 

[hellosailor]

"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?

 

[hellosailor]

Mark-
There is indeed more salt normally found in "marine" engine oils than in inland ones. And, more silicon and other "dirt" contaminants in the ones from inland. Vice-versa.

I once went nuts chasing down some contaminants in a water sample only to have someone finally say "And did you start by cleaning the glassware with Bon Ami? Ahuh, you didn't rinse it well enough." Could be that whoever pulled the OP's original sample wiped a sweaty brow or otherwise contaminated the sample, which is why a single sample is always suspect.

Mitch-
Race car drivers, who really don't have time to look at anything inside the car, traditionally mounted gauges so that a needle at the "normal" reading was oriented at the 12 o'clock position. Looks sloppy if you are reading the gauges, but makes it very much simpler to 'sweep' them with your eye, and notice if anything isn't "the same" as everything else at 12 o'clock. FWIW.

 

[hellosailor]

Good logic, but how *salt* would get into a motor oil plant production line in the first place...That could only be sabotage on the line. Unheard of, AFAIK.