Cat C9, high copper

[sdan27]

This is the latest UOA from our Cat Challenger MT765B with a C9 engine. Uses a Fleetguard LF9691A venturi combo oil filter. This is the second year this oil has been in service. I made mention in another post about the copper being high in this one too which seemed odd since I've done other UOAs on this one that showed very low copper. Using Service Pro 15w-40. I know it uses some oil as I added a gallon a few weeks prior to the UOA.

Hours 1548, 1868
Oil hrs 255, 575

Iron 35, 41
Alum 3, 3
Copp 1, 289
Lead 0, 1
Tin 0, 1
Sili 11, 3
Moly 25, 26
Boro 17, 10
Magn 1068, 884
Calc 1399, 1235
Bari 1, 0
Phos 1329, 1048
Zinc 1506, 1234

Fuel .6%, .5%
Soot .1%, .1%
H2O Visc 12.5, 12.5
TBN 6.12, 6.07
Oxid 12, 14
Nitr 18, 10

Even though its built for it, this tractor doesn't see a lot of hard, heavy work. Mostly pulls our corn planter in the spring since it causes low soil compaction with the tracks and then we used it to pull our grain cart in the fall when the fields were too wet for a wheeled tractor.

 

[SubLGT]

You might want to send in a sample of your unused SP 15W40 to see how much copper it contains.

 

[dnewton3]

Occasionally, Cu can be sourced from a heat exchanger or other system component that has Cu or Cu brazing material; it may have nothing to do with the bearings. There are times when a large piece (well - large to the system, but very small to us) of Cu can be liberated into the oil system. It can become "ground up" in the action of the pump, bearing journals, etc, and then manifests into a high Cu reading. Or, it can be a chemical reaction (but this is unlikely due to your same load and brand/grade of oil).

If you OCI and the Cu drops significantly, then it was a momentary thing and no worry should come of it. If you don't OCI and the Cu stays steady, again - don't worry.

Only if the Cu escalated and other metals became elevated as well, would there be cause for concern of bearing damage. I will note this caveot however:
If you do not OCI, and have leave this Cu elevated in your system, you will be blind to the beginning of any other Cu event, should it arise. Very high Cu readings like this can mask of other real Cu spikes that would be associated with other events.

Everything else looks very good. I suspect it's just a piece of Cu that was liberated and was an isolated event. I'd take a wait and see approach to this; wait for the next UOA and then make a decision.

 

[yucca]

Oil cooler core leaching. Known Cat issue. Call your dealer and ask for the Service letter about. The letter will explain the issue/process in detail.
You can also pull it up if you have access to CAT SIS.

 

[yucca]

I just wanted to show you the "copper spike" on a recent sample on one of our cats.
C-18.

The oil has right at 2500 hours on it.