I was wondering if ya'll know what the oil pressure should be on the 4.0 once it gets too 210 at idle and while driving 50 mph or so?

 

Hi, my Oil Pressure on my 94 with 212,00 is 60 cold and 40 at an idle. I have read that many jeeps run at 20 at an idle and 40 on the gas...Tj

 

TJ is correct- anything above 20 PSI is fine, below that start looking for the cause and try to remedy the problem.
Mine runs 60 cold and 40-50 when warm.

 

Normal is 60 cold and 40 on hot.

Actually 13psi is the bare minimum you should go.

I would start getting worried if you run below 20PSI though.

 

My jeep runs at 40 PSI, but drops to 10 when I am idling... Is that bad?

182,000 miles here...

 

Yea mine is 40 at cold start maybe lil higher it old motor in newer jeep it is llike 10 at idle and 30 to 40 while on gas?is that ok

 

Mine runs 50-60 psi when cold and idles at 40 psi cold. Once it warms up it idles at 18-22 psi and when on the gas stays between 30-40 psi. No knocks or funny noises. I am going to try 20w-50 on the next oil change. Also I flushed the cooland and changed the thermostat and it runs about 180-190 with the stock 180 thermostat. With it running cooler I noticed a small increase in oil pressure like 3 psi.

 

can the oil pressure also be too high?

 

Yes, oil pressure can be too high- that means your oil pump pressure release valve (factory should be 60PSI) is malfunctioning.
Before doing anything major like replacing oil pump verify gauge with mechanical oil pressure tester ($10 @ Harbor Freight). My pressure was reading 2-6 PSI cold and zero once warmed up but was bad sending unit. Tested with gauge and pressure was fine just reading wrong. New sending unit ($18 at Autozone) and all is matching now.