One of my colleagues here in the UK with a 1.6 Turbo Diesel VW camper (Vanagon in the US) has recently installed a preloved engine in his vehicle, fresh 15W/40 mineral oil, still in the garage working on other vehicle issues to get it back on the road, but has been running the engine and getting oil warning light. He ran it up to temp and the oil filter was cold so he figured oil pump had failed, but when he tried to drain the oil to remove the sump to get at the pump no oil came out, so he dropped the sump and found this, solid gelatinized gunk, black in colour
here's the residue hanging from the pump pick up
the old oil that was drained prior to the installation and the filling with the fresh oil that's gone bad appeared to be fine
here's the residue hanging from the pump pick up
the old oil that was drained prior to the installation and the filling with the fresh oil that's gone bad appeared to be fine