High sodium levels in oil

As previously posted, my oil analysis came back all ok except for sodium content, which was at 250.

Scott's old report had elevated levels of sodium, but only to 70, which merited a "C" and an "attention needed" comment from the lab.

The lab rated my sodium level as a "D" with "critical-immediate attention needed". But how would anyone figure out where this sodium is coming from? I have looked at other posted oil reports and they were normal for sodium. I have already checked the MSDS for the Valvoline VR-1 racing oil I was using at the time, but they don't list sodium levels, and I did not add any additives.

I do add fuel stabilizer over the winter when the car does not get driven (Sta-Bil). Again, no info
of value in MSDS.

My engine was rebuilt 1,000 miles ago, and this is the first oil change since, so maybe it's somehow related to the rebuild/assembly process? (only the top end was rebuilt. Tranny was rebuilt as well).

I'm now using Castrol GTX Edge 5W-50 (formulated for classic cars) with ZDDPlus additive for the zinc and phosphorous. I'm worried about continuing to drive the car if something critical is going bad.

Any thoughts on where sodium might originate greatly appreciated.

 

Never mind. Finally found technical data sheet on the oil I was using (Valvoline VR-1 Racing oil 10W-30). It has 490ppm sodium in it's additive package. All my other readings were consistent with the oil's additive content. Interesting that the sodium levels actually went down over time from 490 to 250, while the phosphorous and zinc were slightly elevated from the package.

Anyway, I'm no longer using that oil. Since glycol and antifreeze were at zero I can eliminate head gasket or seal failure. I was beginning to get very worried.

Thanks to all for the help anyway.

 

So sodium really does cause high blood pressure!


I wonder what property sodium adds, and why it was in the additive package?

 

Sodium is part of the detergent package. Just like calcium or magnesium.

 

Crankshafts and other engine components are 'nitrided' in salts at very high temperatures.
That, might be a source of sodium.
I would post your question in the technical section.

Regards, Alberto

 

everything tastes better w/salt

 

the principle purpose of "salt" additives in engine oils is for a "detergent" action...think of it like grains of sand sloshing about and "scrubbing" surfaces and "preventing" carbon detritus deposits from caking up...

I simplify the chemical explanation for a more simplistic lay persons description...

salts used in hardening are NOT a factor in this exercise...period.

FWIW, in my experience, castrol products are rather high in this component-hence the clean, orange hue to engine internals frequently seen....

Lastly, a first change analysis is not as meaningful as several measured trends, as residual compounds as byprodducts of the rebuilding process are typically an uknown variable, thius non-quantifiable...3-4 samples in will yield a meaningful baseline...

 

Thanks to all. I will be sending a sample of every future oil change for analysis as 335 suggested. However, since I rarely get to drive my cars any more it might be a year or 2 before I change the oil once, and many years before I can see any meaningful trend.

At least I'm fairly certain the sodium was from the additive package and not from a blown head gasket. Although I do wonder why the sodium level decreased over time. Some chemical reaction with another molecule (chloride, bromide, iodide, etc. or, god forbid, water)? Almost certainly it wasn't trapped in the oil filter as we're talking micron sized particles of sodium.

The data sheet lists sodium as a "corrosion inhibitor". Funny, but I always thought of salt as a corrosion accelerant. But then again that would be sodium chloride, not pure sodium.