"We had two lab customers whose engine oil analysis reflected elevated sodium/potassium ANd tested for glycol.
One disregarded our suggestion to pressure test the coolant system indicating that this forum indicated that these were normal levels of sodium and potassium for Mobil Clean 5000.. The next oil analysis came back reflecting high wear rates, copper through the roof and higher yet sodium and potassium. Thus the engine experienced a whole round of glycol contamination which could have been minimizd had he followed our suggestion of leak test, exploratory work..."
There are a lot of inaccuracies in this statement that I feel I need to correct. I am the customer that questioned the flagging of high sodium to Predictive Maintenance Services after a UOA on Mobil Clean 5000 5w-30 with 4819 miles. Joe at PMS said that he spoke with a "Mobil Distributor" (turned out to be George at AVLube) who claimed that Clean 5000 did not have Na as an additive. I sent two links from this forum showing normal Na levels to be ~200 ppm. There was no suggestion for a "leak test or exploratory work" after the first UOA, only "change oil & filter (if not already done), & resample at normal interval". I commented to Joe at PMS that if the K hadn't been 137, I wouldn't even be concerned about a coolant leak, but this is a GM 3.4L V6, which is notorious for blowing intake gaskets. I didn't think the Na was anything to worry about, but the K was.
The next UOA with 2990 miles on the oil showed iron at 11 (hardly "high wear rates") & copper at 26 (not exactly "through the roof"). It
did test positive for glycol, & K had increased to 206. I just got the car (my wife's) back yesterday from the mechanic, who replaced the intake gasket, & hopefully all is well now.
Ironically, I used Mobil Clean 5000 in this engine because I got it free after reading about the "5 free quarts of Mobil Clean 5000" on this forum. And the only reason I did a UOA on this car (I do regular UOAs on my diesel pick-up) is because I found out here at BITOG that GM 3.4 V6s like to blow intake gaskets. It turns out that Clean 5000 isn't exactly a good oil to use if you're relying on a UOA to detect a coolant leak.
BTW, I'm not trying to make George look bad or call him a liar. He is very helpful with interpreting UOAs & he is an asset to this & other forums. But I cannot find a single UOA or VOA of Mobil Clean 5000 or 7500 on this forum that doesn't have at least 165 ppm of Na.
Flame suit on & firmly zipped!