I have an 04 psd that cranks for awile than almost turns over. Than I crank it a little more and it runs. Oil pressure reads no oil pressure at idle , bring the motor to 800-1000 rpm than gage kicks in and works than drops at idle.
Does anyone know where to start looking. I already replaced the oil pressure regulator by the crank pully and sending unit up top by the oil filter.
Could it be Hp oil pump, or IPR ?
Ps the truck started fine when parked facing downhill.
200k miles on the truck.

 

Moved to the 6.0L Powerstroke Diesel forum.

 

You have 2 oil pumps, one off the front of the crank (Low Pressure) and then the high pressure. The low pressure feeds the bearings and high pressure oil reservoir. 200k on the clock, how long have you owned the truck for a little history?

 

what John said more info^^

Motocraft oil filter???????

scan for codes

 

Sounds like a fairly significant high pressure oil leak. Check ICP/IPR and air test the HPO system.

 

Are you using a motorcraft oil filter or some kind of aftermarket?