Oil analysis indicates Sodium of 153, an increase from 0, 50,000 miles ago. Potassium is O. Other listings of note:

Iron 100
Chromium 2
Lead 31
copper 3
aluminum 1
silicon 12 (rose from 5 after I ditched the K&N)
Boron 21
Magnesium 297
Fuel less than 1
Soot 0.3 (down from .6 ealier)
Glycol NEG
TBN 8.95
OXID 14
F-Soot 0.36

Why the sodium increase? Does everything else look OK? Sample was in truck 5,000 miles. Truck has 184,000 miles. I switched from Delvac 1 to Rotella 5w40 synthetic.

Thanks

High sodium could be a coolant leak starting, since Rotella syn doesn't have sodium as an additive. Iron & lead seem to be on the high side, too. What were those readings the last time?

Oil Analysis explanation
(http://theoildrop.server101.com/whatisoilanalysis.htm)

Iron was 36 last time. Lead was 8. I also used some Power Service oil extender. I did change coolant to the yellow extended life last time. What, if anything should I do? What about using some of those GM stop leak tabs?