I have seen this twice in my years at a dealership. The oil pump screen getting clogged with sludge on a magnum. I believe this is from letting a blown out plenum gasket go too long and probably a little lack of regular maintenance. My 450K mile 5.2 was clean as a whistle but i kept up on the maintenance and replaced the plenum gasket twice I think.

"Follow me the wise man said, but he walked behind"


'92 D250 Club Cab CTD, 47RH conversion, pump tweaks, injectors, rear disc and hydroboost conversion.
'74 W200 Crew Cab 360, NV4500, D44, D60 and NP205 divorced transfer case. Rear disc and hydroboost conversion.
2019 1500 Long Horn Crew Cab 4WD, 5.7 Hemi.