High sodium content in generator oil

[TheJudge]

On a recent survey a 5kw Northern Lights generator tested high for sodium. The reading in the oil sample was 36 while that in the main engine was only 4. The report said it could indicate the presence of coolant in the oil or a non standard oil additive. Otherwise the genset performed well under all conditions. Have any of you experienced such a thing? They merely recommended changing the oil and filter and retesting in 100 hours. I would hate to buy a major problem.

[jleonard]

Although oil tests are nice, they are not the gospel when viewing only one random analysis. This is a snapshot...you need several over time to be of real value.
I don't have a legend in front of me to know what is "normal" for sodium level so you'll have to tell us that.
Remember they said it "could" indicate presence of coolant. You probably want to monitor coolant level and retest as suggested.
3 years ago I had a very high iron content reported in a tranny oil sample. I was told it was so high the tranny was trashed.
All I did was rebuild it and it is fine. I only replaced bearings because I had it apart.
The reason the sample was high? I didn't know there was a magnet epoxied to the oil pan and I must have taken my sample from the pile of 25 year old iron filings. No "expert" or lab ever suggested that as a possibility.
There are reasons for everything, some are not obvious or commonplace.

[TheJudge]

jleonard, you sound like a smart boater. The sodium level was 36 in the genset and to give a comparison the level in the main engine was 4 and the transmission was 8 which are both regarded as normal. I think I can take a chance on this generator. We ran it under total load for 2 hours without a bobble. Perhaps this reading is an anomaly or could be some screwball oil additive.

[jleonard]

I can also say that I installed a 5kw NL in my previous boat. In my opinion there is none finer. Extremely quiet and that's without a sound enclosure.
It should serve you well.

[skye peak]

Sodium may indicate saltwater, as in NaCl which is salt.

[TheJudge]

The boat is presently in saltwater but there is a closed cooling system. I am inclined to call it an anomaly and keep an eye on it. I will change the oil and filter if the purchase goes through and retest in 25 hours. I have heard nothing but good reports on this model.