Two Cummins 855 UOA

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We have an older Cummins 855 in one of the silage trucks on our farm. Had a great UOA last fall, put about 150 hours on it before we put it away and then this spring it had milky gray oil in it. Took a sample, drained and changed the oil and these are the results. Wondering what you think. The current numbers are to the right.

Iron 16...35
Chro 1....2
Ni 0....1
Lead 3....4
Copp 3....17
Al 2....1
Tin 1....2
Cad 0....1
Sil 3....34
Sod 3....307
Pot 4....621
Moly 158..231
Bor 39...139
Mag 729..974
Cal 1320.1468
Phos 944..1335
Zn 1095.1194

Water Vis 13.3_16.9
TBN 5.8__7.9
Ox 9____14
Nit 13___37


So, I have some issues with coolant in the oil. I'm going to drop the oil pan and pressurize the cooling system and look for drips but do you think the small spike in Copper could indicate a problem with the oil cooler letting coolant into the oil? Since I've had the coolant in the oil, I probably run the engine for less than an hour. Could the copper just be a wear metal caused by inadequate lubrication with all the coolant in the oil? The engine itself has fewer than 2000 hours on it after I did an out-of-frame overhaul on it. The oil cooler was replaced with a take-off oil cooler from a different engine at that time. Also, where could the high Silicon be coming from? Is that from the anti-freeze as well?
 
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Is there oil in the radiator? If the oil cooler was leaking you would have 40psi of oil going into the cooling system.

If the cooling system is clean I would guess it lost a liner.
 
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Copper and iron are concerning......the iron by itself wouldn't rais my eyebrow, but with the copper as high as it is and the silicon....something is is going on...check the air filter, all the intake ducting, and do a pressure test on the cooling system
 
There was no oil in the radiator. I spoke with a Cummins tech and he suggested that the injector cups might be the issue. When I rebuilt the engine, I was in school and reground the valve seats, replaced exhaust valves and reground intake valves and replaced the valve guides. Since the engine is a '79 and I did not do anything with the injector cups, chances are they're 32 years old. I think the spike in copper would kind of indicate injector cups too. I'm going to pull the injectors and then pressurize the system and see what happens.
 
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