I got back my results from Blackstone today and everything seems to be good except for potassium. The potassium level is at 57 ppm. Blackstone suggested that I look at coolant as the source, but also said that it was hard to say for sure that it was coolant as the sodium level was very low. Are there any other tell tale signs to look for in the oil analysis to suggest a coolant leak?

I'll admit I haven't been exactly watching my coolant level like a hawk for a change, but when cold the coolant level is about halfway up the overflow bottle. I put a tick mark there tonight and will start watching it more closely. I do know I have sloshed coolant out through the overflow a couple times in my girlfriends driveway but it has been a while since I've done that.

The engine has about 17k on it and this is its 3rd oil change, with 7300 miles on the oil. The oil was Rotella T.

Here are my numbers.

Aluminum 6
Chromium 2
Iron 50
Copper 5
Lead 1
Tin 2
Moly 1
Nickel 1
Manganese 1
Silver 2
Titanium 0
Potassium 57
Boron 25
Silicon 8
Sodium 3
Calcium 2598
Magnesium 22
Phosphorus 1066
Zinc 1536
Barium 1

% Fuel <0.5
Antifreeze ? <= they put the ? there, it was 0 before even though my potassium was 25 for the first change.
% water 0
% insolubles 0.3

I do have one thought. On this run of oil I ran through 16 tanks of fuel, with 11 of those I ran an additive like Power Service or Optilube XPD plus I've ran a few tanks of biodiesel. Do you think this may cause some of the increase in potassium?

What would you do in a situation like this? What should be my path forward?

Thanks for your help!

 

Here is my report.

 

Thats pretty low miles. I would not get excited but do watch the coolant. You are in the stage of lining out assembly errors and such at this point.

The engine may have some stray greases, sealers, preservatives, paint, etc. on its internal parts assembly procedures and this may be the cause of the potassium, or any aother anomoly on such a new engine. A few more oil changes and another 10 -20k miles and it should settle down as far as the readings. JMHO.

 

I had identical potass. on my previous sample. this Last sample was right were it needed to be so not sure what the cause was.
But I have a though not sure if it holds any truth. The sample that was high was oil from winter driving and I used the block heater and the last one block heater was never used spring/summer. So not sure if that may been the reason. Next sample may tell.

 

Here is the comment from Blackstone regarding potassium on my last sample. Potassium level was 20, universal average is 4.

Potassium may be from the SCR
system. It sometimes shows coolant but we've seen it in enough Cummins engines that we don't think it's a
major issue. The TBN read 6.4, still strong.

 

I had the same thing form Blackstone labs.
I talked with the guy @ Blackstone and he suggested that I take a sample after 1000 miles and see if the levels increase or decrease. My levels eventually went back to normal.
I took the original numbers and figured that there was something like 5 or 6 drops of antifreeze in the oil at one time. Most likely the service man used a funnel that had previously been used for antifreeze. Hope that is the case for you.

 

Well the service man for this was me! There is a possibility that this could happen. I used a funnel from the garage and just wiped it down good.

I did look up the MSDS for G-05 Zerex coolant which I have read is the same as the G-05 coolant used by Mopar. I've read that the only difference is a dye package.

Anyway I read that the main constituents of the coolant are:

Ethylene Glycol 90 to 100%
Diethylene Glycol 1.5 to 5%
Organic Salt 1.5 to 5%
Sodium Tetraborate 1.5 to 5%

I looked up the MSDS's for all the G-05 coolants I could find and none had potassium all had the sodium base.

I did look up Dexcool and it is potassium based. Every other vehicle out here is GM so I could certainly see the cross contamination issue. I guess I'll have to quit using ol dads funnel! I'm sure it's been used for just about everything and wiped down afterward.

 

Potassium can also increase from condensation in the engine if the truck is not always run up to full temperature. Not sure it would be as much as what you have but combined with other possible sources it could help account for it.

 

That would explain my high reading. The sample was taken at the end of winter, and I can go for a week or so withouth the thermostat opening.

 

I could see the not warming up thing doing it to me. Since my crash that wrecked my left leg I don't drive it much unless I'm going on a long trip to keep down shifting. At times I honestly may go a couple weeks without driving it.

I sure don't want to get rid of it though, I love it!

 

my question is how many of you guys have tested your oil on a gasser and why or why not? these engines will go for many many miles/hours with absolutely no wear problems.... i'm saving my money for good oil and filters......i say save your time and money and spend it on good maintenance and you will get over well over 200,000 miles on the engine! (as i am doing)