'07 LBZ UOA @ 175,000

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This is an '07 Chevrolet Silverado 2500HD LBZ Duramax. The truck had 175,000 miles on it at the time of this OCI/UOA (182k or so now), running Shell Rotella T6 5W-40 since about 45,000 and using a Fram PH9100 filter (no bypass or extra filtration). The engine operates daily on a +160 tuner, as it has since about 30k. I do very little towing, and when I do, it's rarely more than 3-4,000 lbs.


Wear Metals (most recent, last):

Cu 3, 3
Fe 58, 46
Cr 1, 1
Al 3, 3
Pb 2, 2
Sn 1, 0
Si 4, 5
Na 4, 6
K 4, 2
Mo 66, 58
Ca 959, 1398
Mg 1156, 996
Zn 1356, 1456
P 1106, 1216


Oil Condition/Particle Count (ctml):

St 37, 39
OXI 18,17
NIT 10, 10
SUL 22, 22
W N
A N
F N
V100 14.6, 14.7


I welcome any informed thoughts or analysis of this sample/history.
 
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to BITOG

How many miles were on this oil change?
 
Originally Posted By: Johnny
How many miles were on this oil change?


Ahh, the magic question...

Both of those were on a 25,000 mile OCI. The first was actually a bit early - closer to 23k, but the second was at 25,150.
 
I think they generally say that iron (Fe) tracks with mileage, so for 23,000 miles, this looks pretty dadgum good. Viscosity is good. Did this analysis not include a TBN (Total Base Number)?

Welcome to the forum!
 
Originally Posted By: Hokiefyd
Did this analysis not include a TBN (Total Base Number)?


Nossir, it didn't. My understanding of the TBN is that it's a measure of, or a method of determining whether the oil can be used further/longer. If I'm correct about that, I would assume the TBN is in an acceptable range, as both samples/tests included the note "No problems currently associated with this sample. Continue sampling at the normal interval."

Feel free to correct me if you think that's an unsafe assumption.


Originally Posted By: Hokiefyd
Welcome to the forum!


Thanks.
 
This is an outstanding UOA. I don't see a soot number... or is is the "St 37 39". I presume that's in ppm. The iron is outstanding for the miles. I'm sure Dave Newton is going to dance with joy when he sees this.

TBN (Total Base Number) will tell you how much of the additive pack is remaining but the sulfation and nitration tells you pretty much the same thing. They are the percentages of 100 percent, with 75 percent generally being the allowable max. Sulfation is the inverse of TBN. In this sample, it was 22, or 22 percent of the 100 percent, which would also indicate a 0 TBN. In my own tests the sulfation percentage correlates pretty well to TBN.

Sulfation, nitration and oxidation are all determined by Infrared Spectroscopy. According to Wear Check, they do not make condemnations based on these numbers alone but 75 percent is the usual limit. Essentially, the TBN alone will tell the tale as much as it's needed to be told.
 
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Originally Posted By: Jim Allen
This is an outstanding UOA. I don't see a soot number... or is is the "St 37 39". I presume that's in ppm.


You're correct, the 'St' number is the Soot reading. The unit listed for it is 'ct/ml.'

Still outstanding?
 
Was this test done by CAT? They use that "counts/milliliter" thing rather than expressing it as a percentage. I don't know how to convert it to percent or ppm but based on stuff I've seen elsewhere 34c/ml MIGHT be around .5 percent.
 
Originally Posted By: Jim Allen
Was this test done by CAT?


It was. I'm in the construction business, so have a CAT rep who stops by every other week or so. It was just the easiest way for me to get started doing UOAs on this truck.

Since I've become interested in it, and after reading and learning more on this site and elsewhere, I'm planning to pull two samples at the next OCI - one for CAT and one for Blackstone (their free kit is on the way).


Originally Posted By: Jim Allen
...based on stuff I've seen elsewhere 34c/ml MIGHT be around .5 percent.


That'd be a good number, wouldn't it?
 
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That would be a great number but I'm not so sure about it now. I really don't know how to convert that but I posted a question. You might contact your cat rep and help us all out by asking them how to convert ct/ml to percent. I have heard reference to a conversion chart on the web but, after a search, couldn't find it.
 
Originally Posted By: Jim Allen
You might contact your cat rep and help us all out by asking them how to convert ct/ml to percent.


I've done just that this morning, and will post whatever response I receive from their lab.
 
From the CAT lab:

"...the numbers you see are not particles per milliliter (that is for particle counts only), they are "UFM" or "Unsubtracted FTIR Method" numbers. These are based on absorbance of infra-red light at different wavelengths. You can convert the soot UFM number to percent weight using the attached chart. Simply look up the number on your report in the "Abs" column on the chart, ignoring the decimals, and to the right you will find the corresponding percent weight result. For example, your most recent soot UFM result was 37, so you would find the Abs line for 0.37, which tells you that your percent by weight is 0.56%. This chart only works for the soot number."

I'm not sure how (on this forum) to copy and post the chart he attached to this email, so I hope this explanation is sufficient.

Given his conclusion that the Soot reading for my UOA is 56%, please also tell me your thoughts about that.
 
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Well, .56 is outstanding for a 25K run. I've seen diesels over 2 percent at 10K. What is the time interval and is this mostly highway type driving. You can wail on it to much with soot levels like that. Can't believe D Newton hasn't commented yet.
 
Originally Posted By: Jim Allen
Well, .56 is outstanding for a 25K run. I've seen diesels over 2 percent at 10K.


That's good news. I haven't seen this stated specifically anywhere, but based on the way you phrased that, I gather the Soot reading is cumulative, as well? If so, can I also assume .56 is no reason to give up on that load of oil just yet?

Would you suggest pushing the OCI to 30k?

Also, based on what I've read and learned here and elsewhere about UOA, I'm thinkin' I may pull a sample at the halfway point - 12.5k, to be able to keep a closer eye on things as I go beyond the 200k mark. Can you (or anyone else) offer any thoughts about that?

Originally Posted By: Jim Allen
What is the time interval and is this mostly highway type driving.


This most recent OCI ran from 08.13.10 to 03.31.11, about 7 1/2 months. It is primarily highway driving, but there's a fair amount of sitting in traffic highway driving there, as well. I do live in the Atlanta area, after all.


Originally Posted By: Jim Allen
You can wail on it to much with soot levels like that. Can't believe D Newton hasn't commented yet.


I'm not sure I follow that, exactly. I think you might be suggesting that I don't wail on it very often. That couldn't be further from the truth, actually. I drive pretty well like an old man the vast majority of the time. My biggest weakness, though, is another diesel truck (or a litle tuner car with one of those obnoxious flatulence-box mufflers, or a late-model muscle car, or a European sports car, or...) sitting next to me at a light, wondering if the incessant whistle really means anything. I'm a sucker for a stoplight-drag challenge, and those occur with remarkable frequency...especially when you're out lookin' for 'em.

The short answer: I stomp on it...a LOT.
 
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I had the opportunity to confer with Meathead over on another forum, and I encouraged him to come over here and join us real lube nuts, so I've already had the priveledge of seeing his UOA info.

25k miles with that kind of performance really puts things in perspective. Especially when some would cringe at the use of the OCOD. Most impressive, would we not agree?

Someday, more people might realize that today's common rail diesels and quality lubes can just go a lot further than they first suspect. These ain't your daddy's lubes any more ...
 
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Now that dino oil can go the distance,what kind of technology is out there to keep my itchy "change the oil finger" at bay?
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Ah - there's the rub. Most of us BITOGers like to wrench; it's in our blood.

I prefer to tinker with "improvements". On my Dmax: added p/s cooler, upgraded the xfer case (before the infamous pump rub got to it), added a pyro gage, improved skid plate protection by adding bracing, made a home-made diff cover to improve cooling, etc. Next up? A rear diff temp sensor (thanks to Jim Allen for getting me hooked on gage-fever ...)
 
I find that gaugewatching fills that deep seated need (perhaps "compulsion is a better word). That carries me through one, two and three year intervals on my various equipment. Besides, I have plenty of work to do.
 
I finally got to the next OCI. I sent another sample to the local CAT folks and, as noted previously, also sent one to Blackstone this time.

[img:left]http://meathead.smugmug.com/Trucks/Williebago-Upgrades/2480091_FvBM56#1553194827_MkHPt37[/img]

[img:left]http://meathead.smugmug.com/Trucks/Williebago-Upgrades/2480091_FvBM56#1553194833_wkswd7f[/img]


Y'all feel free to comment.

I've been cutting filters open lately, too, and that PH9100 from the last OCI had some fairly significant wrinkles in the pleats. I'm curious if this is an indication of filter saturation, and if perhaps I should start changing the oil filter mid-interval. Any input on that idea is welcome, as well.


edit: I'm not sure why those pictures only show as links - not particularly familiar with this forum. The links do work, though, from what I can tell.
 
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