Why wouldn't wiped out camshaft show in oil sample?
I have a problem. I bought my 06 CAT ACERT with 420K miles. Now I have 680K on the engine. It didn't have any oil consumption when I bought it, so when I put my OPS Eco-pure on it, I put in full synthetic mobil delvac 1 esp. I did regular Polaris Lab samples every 20K miles, it had high Oxidation and Nitration from the beginning and base was dropping down quickly, so I never let the oil in longer more then 60K, I was refreshing the oil by draining few gallons with every filter change. But no wear metals signs. After they changed their formula for Nitration and Oxidation, my oil samples were good, now I have 143K without an oil change and level 0 on Polaris oil sample (please see pic of oil sample report). But I started to experience an engine vibration when pulling hard hills coming from the engine, so since I had my overhead done when I bought it 260K ago, I pulled into my mechanics so they can run it again. My mechanic took it apart and found wiped out camshaft and all rockers. Really disappointed, cuz he blames everything on full synthetic oil. I would like to hear some thoughts. I'm gonna replace the camshaft, and all rockers. He also found a broken ring on injector #1 what he says could be a vibration cause, but why wouldn't I get any fuel in my oil??? I always had less then <1 of fuel dilution. Do you guys think I should put mineral back in? or should go back to shorter oil change intervals???
Please see 2 picks of cam...
Any thought very appreciated... Thank you
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