High Copper levels.

[SigShooter]

The vehicle is a 2008 GMC Sierra with the 5.3. I bought the truck used about 18 months ago and it had 42300 miles on it. Mileage now is 59149. Did my first UOA with 4300 miles on the oil, using Quaker State 5w30. It came back saying most wear metals look ok but Copper was a little high at 59. I guess the average for this engine is 29. They said it could show excess wear but wait for another uoa to determine if that is the case.

What parts are Copper? Would it have anything to do with the way I drive it? Thanks for any help!! Dennis.

 

[LeakySeals]

Check out the UOA's and info on here regarding GM engines. What I found is copper and other metals are high compared to other engines. Not an indication of a problem, just how they are.

 

[Falken]

There is a brass bushing that connects the piston head to the connecting rod where it is press fit with the gudgeon pin.

If your oil eats away at copper change oils on next OCI.

I only use oils that give good wear results on all metallic components but FE (iron) is what my eye looks for first.

 

[Highline9]

So how sure are you that the 5.3 has bushed connecting rods?

 

[Highline9]

pressed fit

http://www.summitracing.com/parts/SLP-H1132CT25MM/

 

[Falken]

Pressed fit only refers to how the gudgeon "wrist pin" is held in the piston head, sometimes it is held in place with a circlip or c-clip in a groove on the wrist pin.

The wrist pin on a press fit application means the wrist pin doesn't rotate in the sides of the piston, but where the small end of the connecting rod is joined to the piston by the wrist pin there is a brass bushing there in the eye of the connecting rod hole, so the connecting rod doesn't wear on the wrist pin, there is the brass bushing.

People don't usually see this bushing because to get the wrist pin out of a press fit application to see the upper end of the connecting rod is very difficult. So that is why it gets forgotten, but it is a VERY important bushing.

 

[Kestas]

Are you sure the 5.3 wrist pins are bushed? This feature is usually reserved for high-end engines. I don't often see it on production engines. Though they may help with wear, they reduce the available cross section at the pin end of the connecting rod where fracture can occur. It also increases the reciprocating mass of the engine.

 

[Donald]

If the comments are from B/S, I would not pay a lot of attention especially to the universal average. Look through this website for similar engines with similar mileage and see how the copper is. Unless there is something odd, the wear metals will be linear with mileage (on the oil).

Did you get a TBN? If not always get it.

 

[SigShooter]

Yes the uoa was from Blackstone, I've looked at other uoa's from similar engines and haven't seen any with this level of Copper, also I did not get a TBN.

 

[dnewton3]

Blackstone develops it's universal averages from each engine series, so the numbers you see are indeed fair and accurate.

They do NOT homogenize the data across all submissions; they are uniquely tailored to each engine family. As an example, when I see the universal averages in my UOA for my Durmax 6.6L in my Chevy truck, those universal averages are specific to all vehicles that run only that 6.6L diesel engine; they are not crossed into other diesel engine results. Same goes for the 6.0L PSD, versus the 7.3L or 6.4 or 6.7L Ford diesels, nor the 6.7L ISB. Each "universal average" exists for each engine family.

Now, in regard to the Vortec engines v-8's (4.8, 5.3, 6.0) I'm not exactly sure if they sub-divide down in regard to displacement, or just average across that engine family line, but since those engines are basically bored/stroked versions of each other, there is good cause to see similarities.

You need to know how your exposure (mileage) compares/contrasts to the "UA" of the UOAs. Did your sample run at or near the same at the universal exposure? Typically Blackstone will indicate what mileage those UAs are based upon. If you are near the UA mileage, and your Cu is 59 when the "norm" is 29, then you indeed have a high Cu reading. It is true to say that many GM products have higher Cu readings, but that is NOT an automatic license to just ignore anything that is above unviversal average, because that universal average already takes into account the general metal counts for your specific engine family.

That should not be an indication to panic. It is cause to contine to monitor conditions, and stay as consistent with your inputs as possible, so that shifts in ranges or trends will help you realize what's truly going on with your lube selection and maintenance program.

 

[smonska]

Yeah, GM LS engines throw a lot of copper. See my UOA from my 10' Corvette, same engine family, I have 286! I would be thrilled to have copper in the 50s.