Talking to a retired fleet mechanic changed how I read oil samples

I was swapping stories with an old timer at the parts counter last Tuesday, guy must be 70 if he's a day. He asked what I do with my oil analysis reports and I said I mostly just check the wear metals, toss them if the numbers look decent. He laughed and told me he always looked at the viscosity and the fuel dilution first, said the metals just tell you what already broke, but dilution tells you what's about to. He showed me a report from his own truck where the iron was fine but the fuel was at 4 percent, and he said that's how you lose a crank bearing at 200k miles. That conversation hit different because I've been doing this for 15 years and I never once thought past the obvious numbers. Has anyone else had a simple tip from a stranger that completely changed their diagnostic routine, or do I just have blinders on?

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the_faith3d ago

Old guys know stuff the manuals leave out... that fuel dilution tip is gold. Reading viscosity first catches problems before they get expensive, way smarter than chasing metal shavings. Now I check every report different, thanks for sharing that story.