Inconsistent Oil Pressure

[SFab]

Hi Guys! Hoping you can educate me on what is happening and help point me in the right direction for a fix or reassure me everything is okay. I stare at my oil pressure non stop now.

I drive a 98 wrangler and about 6 months ago, my oil pressure dropped to zero and my jeep stalled. I took it to the mechanic and got the oil pressure sending unit replaced, got a new high volume oil pump which bumped my PSI up from 60 to 80, and new oil. Now most often when I first start the car, I have 80 psi in idle and when I have the foot on the gas. The more I drive, the more it tends to drop in idle. Is this normal? After ~10 minutes it gets to 70 psi in idle and over 50 min which I've only done once, it got down to 60 psi in idle.

This is the most sense I've made out of it. Sometimes at one light after the engine is a temperature, it will sit at 70 psi and at the next light 30 yards away it will sit at 80psi. I understand the oil will heat up and it should lower the psi a bit, but is this something I should be concerned about? What could be causing it?

I used to drive a 2002 wrangler sport and and before this car broke down, I don't ever recall the PSI changing.

 

[Winks42]

80 psi is really high to me, I might be wrong but thats dangerously high but someone can correct me. oil pressure will fluctuate as the rpms go up and down , that is normal. In my jeep when I idle after warming up I get down to ~20psi and it stays 40-60 psi while driving around town. I would hook up a mechanical gauges to confirm your oil pressure. 10psi per 1k rpm is pretty normal

your 2002 wrangler had a dummy oil pressure gauge and would not move unless the pressure moved to some extreme amount, the 98 has a "real" gauge and will actively show your current oil pressure although not 100% accurate.

What weight oil are you running?

 

[Jerry Bransford]

Approximately 10 psi per thousand engine rpms is appropriate and a good guideline for acceptable oil pressure. Oil pressure goes up and down as the engine rpms go up and down.