Oil Report

ness5575 · October 15, 2010

I have gotten my oil tested on the past 3 oil changes I have done on my 08 Suburban. I did the first one for "fun", and then when the results came back not so great I ended up doing the next 2 to see what is going on.

The tests keep coming back that copper and lead are really high, and their comments say that "this engine does not appear to be wearing well." I have used Modil 1 oil and filter since day one, but apparently this truck doenst like that oil? Does anyone have any inights or comments as to what could be going on?

Oil_Report.pdf

Z45 · October 15, 2010

Copper and lead can also come from the engine oil cooler but they never mention that and jump to the conclusion it has to be bearings. Not very though of them not to point out alternative sources.

CATERPILLAR-HIGH COPPER
Per Caterpillar, high levels of copper found in 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 the surface of the tubes and then coming 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 in 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 oil brands can chemically disrupt this film and begin the oxidative leaching processes again. This can occur in any system with a cooler core: Diesel or gasoline engines, Transmissions or Hydraulic systems.

SOURCE: Stavely Fluid Analysis, courtesy of Caterpillar Inc.

dennismc · October 15, 2010

GM Engines shedding Copper well into the 30k mark is pretty common from what i've read, you might also post this on "Bob Is The Oil Guy" website, they have a thread just for UAOs, Maybe they can shore some opions

on what they think.

Ryan00TJ · October 15, 2010

GM Engines shedding Copper well into the 30k mark is pretty common from what i've read, you might also post this on "Bob Is The Oil Guy" website, they have a thread just for UAOs, Maybe they can shore some opions
on what they think.

This seems to be the trend. I ran a few samples thru Blackstone on my 02 LS1 Camaro SS and they all had higher levels of copper and lead but only thru the 10-15K mile range and they started falling thereafter. Post over at bobistheoilguy.com for some more indepth answers. I use to post over there and they are very smart and might be able to pinpoint things.