2004 dodge RAM 1500 5.7 hemi, I just replaced
lifters, push rods, and rocker arms flushed oil
system and changed oil now after engine warms
up and about 45 minutes of driving the oil pressure
drops, shut off engine let sit about a minute then
start engine and oil pressure returns to normal
happened three times before I reached my
destination any ideas would be greatly appreciated
Sounds like a failing oil pump, same thing happened to me on my Eddie Bauer Ford Bronco, started up fine with good oil pressure, would drive about 15 minutes, oil pressure would drop out lifter would start clicking, shut it off and wait 15 minutes, start it back up, oil pressure would come back to normal and drive about 10 minutes and it would do it again. Replaced the oil pump and no more problems.
Drove truck home from work with no issues drove all day today with no issues could this be caused by sludge in the oil pan and not a bad pump
If there is that much sludge then it will foul the oil pressure relief valve as well as ruin the oil pump, cause sludge is abrasive and will scar the pump rotors so they can no longer make enough pressure.