2006 Silverado 4.8 UOA Peak 5w30

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Haven't logged in in a long time, so hopefully I attached the report correctly. I was concerned about some coolant loss with no visible leak found.
This truck has the Castech heads known for cracking. I did change the radiator cap and haven't seen any loss since, but it's still early.
I did pressure tests with a loss of 1 PSI per hour so could be a leak or the tool I have.

Cliff notes:
Truck is a 2006 2WD LT 4.8. 99,500 on the ODO. Peak 5w30 conventional (got from NAPA when it was .99 cents per bottle!). Now I have 5w30 Maxlife Blend in it and will run that for 6 months, then retest.

Copper is typically high in these trucks but was surprised to see it still high after 99k miles. Figured the engine should be broken in by now.


Please give me your feedback if you have any.
Thanks and take care,
Mike

[Linked Image]
 
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Pretty unimpressive oil honestly. Copper is definitely high after 3,000 miles.
 
Originally Posted by Doublehaul
Do you have a oil cooler on this truck?


Yes, and that's my other thought about high copper. I've heard some oils cause more copper leeching than others but I have no proof.
 
Originally Posted by dogememe
I'm too lazy to Google what years had the defective heads? Would my 01 5.3 have this issue?


As far as I understand, yes. Castech 704 I believe. You can see the 704 on the head. It's still rare but there was definitely a bad run off heads. Worried me enough to send in for a UOA. Saved me from pulling the valve covers. Lots of info out there if you wish to pursue it.

Mike
 
Originally Posted by Doublehaul
Originally Posted by Triple_Se7en
Numbers read pretty subpar oil adds. Stick with the more major brands like Pennzoil, Valvoline, Castrol......etc.


Seriously?



Every few months he chimes in with worthless advise.
 
You're loosing it from somewhere (duh) and it could very well be the oil cooler. If you investigated the particle size of the copper you could ascertain where it's most likely coming from (for example, bearings v. oil cooler) as different parts shed different size particles. I forget the name of the test, something like "stain gram" or other, dunno. Fortunately coppers a soft metal so it's not going to promote wear and as long as your other wear metals aren't abnormal there's nothing to set your hair on fire about. So BS is right in this regards - just keep an eye for any developing trends.

This article about copper might be of interest to you... interestingly, changing of oil brands/formulas can initiate a "spike" in copper levels. Read article to learn more about that phenomenon.

https://testoil.com/data-interpretation/sources-of-copper/

*otherwise a pretty unremarkable report, which is a good thing....
 
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This is a fascinating read that let me to think about my use of MOS2. I told Blackstone that I used about 1/3 of a can on this oil change, which I completely forgot to mention here and they didn't reference in their comments.

If this article is correct about sulfur possibly attacking copper parts, this could be why it is high. If so, I plan to discontinue using it.

What are your thoughts?

Thanks,
Mike
 
Originally Posted by bigmike
This is a fascinating read that let me to think about my use of MOS2. I told Blackstone that I used about 1/3 of a can on this oil change, which I completely forgot to mention here and they didn't reference in their comments.

If this article is correct about sulfur possibly attacking copper parts, this could be why it is high. If so, I plan to discontinue using it.

What are your thoughts?

Thanks,
Mike



I would never use MOS2 in anything I cared about. But this is just me. Plus were did it go because nothing in the UOA is abnormally high additive wise. Most of the MOS2 is likely stuck to the oil pan.
 
Originally Posted by dave1251
Originally Posted by bigmike
This is a fascinating read that let me to think about my use of MOS2. I told Blackstone that I used about 1/3 of a can on this oil change, which I completely forgot to mention here and they didn't reference in their comments.

If this article is correct about sulfur possibly attacking copper parts, this could be why it is high. If so, I plan to discontinue using it.

What are your thoughts?

Thanks,
Mike



I would never use MOS2 in anything I cared about. But this is just me. Plus were did it go because nothing in the UOA is abnormally high additive wise. Most of the MOS2 is likely stuck to the oil pan.


Well in regards to where did it go? That's a great question and I found it a bit disappointing when I received the UOA.

I've hashed out MOS2 in multiple threads many years ago here, some seemingly as long as a classical novel. In those conversations, I never heard anything negative about the sulfur component but I'm not a chemist so I don't know how it breaks down nor what circumstances it may do so.
 
I also wouldn't put MoS2 in any of my vehicles, but not because of fear of sulfur. The oil I have in my 2002 Tahoe 5.3L is 1.85% sulfated ash (>3x the API limit) and my copper wear at 10k mile OCI is
I'd also like to note that the metal shown here is realistically about 20% higher than what is shown there. Blackstone is pretty notorious for reading low. I communicate with several blenders and formulators, all of which conduct periodic quality checks on their batches, and none of them use Blackstone for that reason.
 
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Originally Posted by RDY4WAR
I also wouldn't put MoS2 in any of my vehicles, but not because of fear of sulfur. The oil I have in my 2002 Tahoe 5.3L is 1.85% sulfated ash (>3x the API limit) and my copper wear at 10k mile OCI is
I'd also like to note that the metal shown here is realistically about 20% higher than what is shown there. Blackstone is pretty notorious for reading low. I communicate with several blenders and formulators, all of which conduct periodic quality checks on their batches, and none of them use Blackstone for that reason.



I don't agree it's real easy to lookup and compare. There can be up to around 10% variance between Wearcheck Blackstone, WIX, CAT. Not 20% you have a habit of writing well written and thoughtful posts often there is a tidbit of inaccurate information.
 
Well, I guess the bottom line for me is, I know I'm not looking at a cracked head and that was a huge relief for me when I received this report. I'll keep an eye on the coolant and see if the new cap has fixed my issues.

I'll skip the MOS2 moving forward. I took the time to read through the forums on the subject. Trav's thread about it collecting in the pan really changed my mind on the product.

I have probably 50 quarts of all kinds of brands of oil in 5w30, so I'll retest and see what's happening with the copper. Current fill is Maxlife. I don't put allot of miles on it, so was doing yearly oil changes until this issue came up. I think I'll go to changing every 6 months until I know more.

Anything I'm missing here?

Thanks for the comments!
 
Originally Posted by dave1251
Originally Posted by RDY4WAR
I also wouldn't put MoS2 in any of my vehicles, but not because of fear of sulfur. The oil I have in my 2002 Tahoe 5.3L is 1.85% sulfated ash (>3x the API limit) and my copper wear at 10k mile OCI is
I'd also like to note that the metal shown here is realistically about 20% higher than what is shown there. Blackstone is pretty notorious for reading low. I communicate with several blenders and formulators, all of which conduct periodic quality checks on their batches, and none of them use Blackstone for that reason.



I don't agree it's real easy to lookup and compare. There can be up to around 10% variance between Wearcheck Blackstone, WIX, CAT. Not 20% you have a habit of writing well written and thoughtful posts often there is a tidbit of inaccurate information.


I'm not talking about the10% margin of error. I'm talking about Blackstone commonly being down 20% compared to everywhere else.

For example, here's PQIA's results of this same oil.

http://www.pqiadata.org/Peak5W30.html
 
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