98 5.9 oil presure problem

[modman84]

i have a 98 grand with a 5.9 liter and the oil presure drops to the bottom of the scale at operating temp (210 deg) at idle with alittle gas it rises to 40 psi. i have just purchased this and do not know the actual miles on engine as the old owner said the engine had been replaced.i have changed the oil and used 10-40 with a quart of lucas and still has problem. there is no lifter noise while idling but when i pick up the gas there is a slight knock but goes away with oil presure rise.could this be an oil pump problem or bearings or both. and can the pan be removed while still in jeep 4X4. Thanks for any info

[arks]

Well, I can tell you that the oil pressure on my 5.9 doesn't vary that much. It's never at the bottom of the scale, even when idling. You might want to have a mechanic look into it. I don't know if the pan can be dropped easily. Good luck.

[jusber15]

I had this problem on my 5.9 Durango which I believe is the same motor. It is known that the oil pump pickup screens get clogged with goo and dont allow proper oil flow to the engine. I had to pull the oil pan off and replace the oil pump and pickup screen.