redram said:
You must run Cat equipment - they seem to have a known problem with the copper oil coolers and the manufacturing process of soldering the copper lines in the cooler. We've seen that for several years and believe that there is a Cat Bulletin on at least one series of engines explaining this. Has nothing to do with actual copper wear - it is a copper salt from the flux used in the coolers.
As an Amsoil jobber, I do many oil analysis on used engine oils, and because of this, I have received from Amsoil Inc. a letter regarding this phenomenon.
Here is the letter I received.
Per Caterpillar, high levels of copper found in Motor oil analysis are a result of engine cooler core “leaching”. The Zinc additive in Diesel motor oils reacts with the copper cooler core tubes at high oil temperatures. This chemical reaction results in copper oxidation products forming on surfaces of the tubes and then comes off into the oil as it washes over and around the tubes, Heat is a catalyst to this chemical reaction , the higher the oil temperature, the greater the rate of oxidation and the longer the reaction process is sustained.
This does not cause any damage to the cooler core, or to the engine.
However, you will see the copper reading elevate to over 100 PPM. Copper is not a particulate in this case, but is a solution in the oil. The PPM will start relatively low and increase over 100 PPM and stay at high levels for several intervals, and then return to normal. During the oxidation process, a hard film forms on the tube surfaces exhibiting the appearance of clear varnish. Changes in operating temperatures, and/or changing brands can chemically disrupt this film and begin the oxidative leaching process again. This can occur in any system with a cooler core: Diesel or Gasoline engine, transmissions or Hydraulic systems
SOURCE: Stavely Fluid Analysis, courtesy of Caterpillar Inc.
As stated above, this information was sent to me from Amsoil Inc.
Wayne
amsoilman