when i first bought the truck it ran great for a couple of months, then it started to drop oil pressure every time i stopped with the factory gauge. I researched and thought it could be the oil pressure sending unit, i replaced it and no luck. I then bought a aftermarket oil pressure gauge, at idle when warmed up it reads 0-5 psi. I recently replaced the oil pump with a high volume one and a new pickup screen. Now it reads at idle 10-12 psi when warm. I hooked up the factory gauge back up and it started to drop again when its warm. What have i missed or is it possible the stock gauge that is messed up? truck only has 72000 and there was a good amount of sludge in the bottom of the pan when i took it off. only have 400-500 miles on new oil and filter.

 

That is too little pressure, for sure. The Hemi in my C runs about 30-35 psi at idle, 50+ on the highway. I wonder if the return to the pump is clogged.

BTW, never stop with the factory gauge. Always use the brakes.

 

when you cleaned out the pan, did you check the pickup screen and tube----others with the 4.7 have had some serious issues concerning sludging, and some of those were severly plugged. "0" psi

 

might help to run some sea foam through the engine or marvel mystery oil to get that sludge out

clogged oil veins in an engine is like clogged arteries in your body.......bad

 

When i replaced the oil pump, i also got a new pickup tube. I have heard about running the seafoam though the engine before, might have to do that and see how much sludge i get out of it.