Pulled the valve covers on a 2003 Ranger with 210k and the difference from 6 months ago surprised me
Back in October I popped the covers on this 3.0 and it was straight sludge, like brown pudding on the rockers. Pulled them again yesterday after two short oil changes with a cheap high-detergent oil and the whole valley is bare metal now. The owner drives it 40 miles a day on Route 20 in Rockford so it gets good and hot, which I think did most of the work. Anybody got a favorite cheap oil for slowly cleaning up a neglected engine without knocking stuff loose?