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I have a C-15 Cat with 486,000 miles on it. I have been using a gulf coast bypass filter using Amsoil synthetic oil and doing regular oil analysis. Last sample showed an increase in copper from 19 ppm to 320ppm. Lab advised to resample thinking there was an error. Resampled and came back at 580ppm with an increase on the iron count as well. Along with this the Gulf Coast Filter has been collapsing. The Manufacturer says this only happens when the filter is filtering out water, said to check the oil cooler for leaks. Could an oil cooler failure cause the increase in the copper count?
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If your cooler core is copper then yes failure of the core could put significant amounts of copper into your oil if it is leaking. You should also show an increase in elements assiciated with coolant such as silicon, boron, chromium. An FTIR test should indicate the presence of glycol if present. In the absence of these, seeing an increase in copper then an increase in both copper and iron could indicate failure of thrust bearings or rod/crank bearings. See if you can identify the composition of the various wear points (OEM data) and look for corresponding increases in those elements to pinpoint the source.

Does this unit got rebuilt recently?
Any maintenance work carried out? Copper alone
will not be a problem,usually oil cooler core
leaching,ceartain anti-seize compounds,initial
break-in-wear results in elevated copper levels.
If the engine is idle for several days,condensa
tion of water from oil cooler shows high copper.
Cat dealers perform microscopic analysis to confirm the copper is from wear or leaching effect.

Thanks for your input, took the engine to CAT shop and found the rocker bearings were going out on the exhaust side and starting to on the injector side. They seem to think it is oil related, but cannot give me any evidence of where the oil has failed. Have been on oil analysis program for some time and have all the results showing the oil is still good.

I have seen this happen when the oil supplier changes additive chemistry. There is a very sudden spike in the Cu ppm readings. This is not copper wearing away but rather an electrochemical reaction between the copper oil cooler and the additive chemistry. After awhile, the copper level does settle down once the additive has a passivating effect. You will find that on a Cat C15 engine, after 2 to 3 oil drains, everything settles down and the copper levels are back to normal. It may pay to ask the oil supplier if the additive chemistry has changed and if they are seeing similar effects on other C15 engines.
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