Confused by oil analysis 2005 Dodge with Cummins

[tesla440]

Good day everyone,

I was recommmended to post here. I'm hoping that you can enlighten me with my oil analysis from NPower (Cummins service).

According to NPower, my oil sample came back with high levels of Silicon & Sodium, but with no Glycol present. They are saying that it's a coolant leak. But wouldn't the test have to show Glycol also present? The engine uses HOAT glycol based coolant.

Also all of the other metals & Potassium levels were down from the last test 7500mile before.

They state that all engine wear rates are normal. Where Sodium level (oil additive/coolant) and silicon (coolant additive) are higher than typical or dirt present possibly gaining with the coolant.

I did the oil change where I found that my oil filter was not on as tight as I always tighten it. So there there was very light seepage that was going back towards the turbo propeled by the radiator fan. Since my boot on my inlet was not seated correctly do to the aftermarket TAG (air striaghtener) I leaked to the turbo inlet. I believe that is my source for the silicon.

As for the sodium, when I submitted my sample I told them it was standard Rotella T 15W40 when actually it was synthetic Rotella T 15W40.

Or do you think that the sodium & silicon levels be high from burning WMO blended with #2?

I'm kinda new to this analysis. From what I read about older diesel (pre-emission) was that the combination of silicon & sodium was considered dirt ingestion.

Any and all input would be great.

 

[dnewton3]

Actually, you've got a great start to the concept of what MIGHT be wrong.

I say "might", because you're somewhat operating under some conditions that could skew your UOA. Yes, intake leaks can cause silica contamination (often seen as silicon in a UOA). Also, the waste motor oil might be shifting some things as well.

As this point, I'd seal the air leak (which you seem to have done) and also run nothing but straight fuel from a reputable source. Then do another UOA and see if the high silicon and sodium repeat.

You're onto the right analysis; you just need to keep going to rule out certain contributors. Also, it's helpful it you post all the data from all the UOAs, so that we can see it. Most prefer you just type out the results (takes longer, but those that have broswer issues can still see the text) rather than posting a PDF.

... and Welcome to the site!

 

[tesla440]

Here is the UOA report that I'm diagnosing:

Aluminum-7
Chromium-4
Copper-39
Iron-67
Lead-7
Tin-5
Silicon-32
Potassium-7
Sodium-67
Moly-8
Water- Oxidation-6.9
Visc@ 100-14.7
Glycol-ND
Fuel- TBN-6.3
Nitration- Soot-1.3

From what I can tell, everything else looks good, but Silcon, Sodium. The higher copper & iron I'm guessing is from running waste motor oil.

 

[dnewton3]

Ok - we're getting better info.

Your UOA sample was 7500 miles, correct? And you say the wear metals were "down" from the previous UOA, yet the Cu and Fe are still (what I would consider to be) high? Also, your fuel and soot seem a bit high for 7.5k miles. Are you using EGR, or is it deleted? Is this a "tuned" engine?

I know that this answer is not fully going to fulfill your question; you likely want a direct, definitive answer right now. But I still believe you can't make a snap decision on this UOA.

Reduce your input variables. Quit using the WMO for now.

 

[tesla440]

yes correct at 7500miles. I do agree with you about the Cu & Fe being high.

As for the fuel has not changed since I start taking samples 30,000 miles ago. Soot level is actual normal since I've started sampling. The Engine has 3 injection evens to cut down noise & decrease emissions. So my soot particals are much smaller and turn my oil black instantly upon startup. It's been that way since I've owned it at 8,000miles on the ticker.

I still have a full tank that I need to burn up before I can be running straight diesel (too much of a pain to drop the tank to drain. The truck does not have a standard EGR setup. Its all done in-cylinder via change exhaust valve closing sooner and the 3rd injection event.

 

[dnewton3]

I'll be the first to admit that coolant issues confound me, moreso than other mechanical issues. They are flat hard to diagnose and track down, when they are small.

I understand, and agree, that you'll have to burn out the current WMO load of mixed fuel. No problem here. It will just set back the clock a bit on a "clean" fuel starting point.

The key to using UOAs for diagnosis is to reduce as many input variables as possible, so that only the issues stand out, and do not get blotted by the noise of change. If you haven't yet done so, consider choosing just one oil product and stick with it through several OCIs. If you like RTS (a fine product) then stick with it year round. Cut your OCIs and UOAs to 5k miles (again, for consistiency). See if things settle down. Then post up the full results.

Keep us informed; we'll stay tuned.