How come the oil pressure in my friends jeep 4.0L likes to go down to almost nothing after it warms up? Is it just the oil pump or do I have a bigger problem? The pressure is ok when driving, but at idle it goes down very low, once the heep has warmed up? anyone else ever had this problem, and what did you do to fix it? Thanks again.

my first guess would be to put proper amount of oil into crank case

and the correct grade.....10-30 vs. 5-30 is a pretty noticable diff.

Thanks, It is right at the full level, and it is 10w 30? that sounds right to me. Any other things it could be?

hey phillip, i think u post more things for Denny's jeep than ur own truck, or anything else eh?

Changed sig. for Denny, Do you like it John?

I run 15W40 in the summer. oil press at 10-15 psi at idle hot. Tryed a new oil pump a year ago and checked the crank bearings, they are ok. So on my jeep it is probly a cam bearing. No knocking or other bad shit yet so I just up the oil weight and drive on

funny cause it fits his jeep pretty good eh?

93 yj just replaced the pump month ago after no pressure i think i had 180k on it replaced the old one with a mildon oil pump from canadian high performace out of pg nothing to it with the suspension lift on my side

sounds good man thanks. We are going to try a pump, then if it still does it we will just run thicker oil as that means the cam bearings are gone Oh-well. Thanks, again

not very often you'll hear of cam bearings going. first thing to do is get a manual gauge and hook it up. heavy oil is not the answer unless your turning 8000 rpm or more

just swap that frickin AMC junk outta there and put a 350 in it like mine!!!