Sodium & potassium up a little

[JimT]

Each lab is a little different, but usually they will flag anything beyond a certain threshold. However like Mrkentee said you want to watch for trends and changes. At low levels (those numbers are typically parts per million) it's not a major problem, but a spike could be an early warning before a major breakdown occurs.

According to the lab I use:

Code:

Sodium contamination in:

Reciprocating Engines can come from
Sodium from Antifreeze Inhibitor (Coolant Leak), Additive in Unleaded Gasoline Engine Oils, Salt Water, Spray Wash

Gear Systems can come from
Additive from Sodium Borate Gear Oil, Sodium from Salt Water, Spray Wash, Environmental Contaminant

Potassium contamination in:

Reciprocating Engines can come from
Antifreeze Inhibitor (Coolant Leak), Solder Flux, Metal Coatings, Pot Ash

Gear Systems can come from
Additive from Potassium Borate Gear Oil, Environmental Contaminant, Solder Flux

I included the Gear Systems reference because you mentioned adding StaLube Gear Oil. However, if this StaLube has been added in the past without this showing up in oil samples then it is most likely coolant intrusion. I'm no expert, but anywhere coolant can meet oil. The numbers are pretty low so even if you do go looking you may not be able to find the cause yet. Personally, I'd probably make an unscheduled EGR tune-up and look for any signs of coolant, as a leak there could cause bigger problems with the EGR and DPF.

On my samples those number are constantly up and down, but always in the single digits (0-6ppm). As I haven't found any leaks from the EGR or turbo I'm guessing it's just my worn and previously abused 541,000mi engine.