Thanks for the good advice. My 89 4.0 XJ was showing 5 lb oil pressure at idle but only after fully warmed up. With only 120K miles and running strong and getting good mileage I was scratching my head. Pressure that low should have the lifters clopping and rods knocking in short order. As recommended by others here I installed a new Mopar 56026782 oil sender and NAPA gold filter. The sender looks different than what was on there but according to 2 dealers it is the right part number and fit perfectly. Now I idle @ 20 lb oil pressure fully warmed up.
This pesky Cherokee is the only critter out of about 40 cars I've owned that has had 2 senders fail, after an extensive total overhaul of the cooling system including 2 row all brass radiator, pump, fan clutch, T stat and housing, all new tubes and heater control valve, all hoses and pressure tank, a good flushing (Boy the crap that came out of the heater core!) and exact 50/50 mix of coolant made with purified water and burping testing I kept getting the gauge marching right on up into meltdown readings. Again the sender was the problem.(The system was shot and badly needed the repairs, I was stumped upon finishing the overhaul till getting info here.)
This pesky Cherokee is the only critter out of about 40 cars I've owned that has had 2 senders fail, after an extensive total overhaul of the cooling system including 2 row all brass radiator, pump, fan clutch, T stat and housing, all new tubes and heater control valve, all hoses and pressure tank, a good flushing (Boy the crap that came out of the heater core!) and exact 50/50 mix of coolant made with purified water and burping testing I kept getting the gauge marching right on up into meltdown readings. Again the sender was the problem.(The system was shot and badly needed the repairs, I was stumped upon finishing the overhaul till getting info here.)
arty1: