If it's low then getting thicker oil won't help. If oil was blood and you have low blood pressure, you don't thicken your blood.

>>14135286
your oil pump is probably worn out.

>>14135326
on cold crank it will be 40 psi then slowly degrades until if i'm at a dead stop it will be at 10 and sometimes will turn on "check gauges" dummy light. All the while the temperature fluctuates with the oil pressure.

>>14135345
either your pumps/sensors/gauges are worn out.

and by fluctuates, the oil drops and the temp rises? what do you mean?

>>14135286
will it increase with engine rpm at all? no bad engine noise?

http://www.jeepforum.com/forum/f19/4-0-low-oil-pressure-idle-fixed-1304679/

>>14135391
I pretty much came to that conclusion i'm just not sure where to look and i don't wanna just start replacing parts if i don't have to. Exactly what i mean. Oil pressure goes up and the temp goes down. Sometimes it'll hold at 10psi, sometimes check gauges light pops on. When the light is on there's no piston slapping so i'm not lead to believe it could be a cracked head or gasket. Idfk

>>14135392
Wow, so he took the sending unit off and turned the car on and revved the piss out of it and it fixed it? Fucking jeeps dude...

You're fine. Cherokees have a real time oil pressure sensor, so when you're at idle and your engine isn't moving around much, oil pressure drops and the gauge drops to reflect that. It's completely normal and not a problem.

>>14136418

This. If everything still sounds good, take it for a drive and watch the pressure under acceleration. If it goes up as you speed up, it's normal. If it stays low, you may have an oil pump problem. If its constantly at 0, clean the gauge cluster connector and rub some dielectric grease on it.

I have an 89 and its starting to get some serious blowby. 210k miles and Im using HM 20w-50 already.
Advice?