What is "normal" oil pressure?

[ShinyXJ]

What is a "normal" reading for my oil pressure gauge? I recently broke the sending unit while changing my oil and replaced it, and it still seems to read high, around 60 most of the time. I think this is about where it used to be with the old sending unit, and I always thought it was high.

Is this a normal reading or if not, what should I be looking at?

Thanks,

Scott

[Jay Welch]

I was surprised at what is considered normal on these. I recall the low "normal" is 13 lbs and high is around 45 but I don't have my manual with me. I compared my sender/gauge with a mechanical gauge and found that my reading was lower than actual on the mechanical gauge.

I put my mechanical gauge on the end of a new grease gun hose and adapted the end to fit into the block so it's easy to install and read.

Good luck,
Jay in MA

[Eagle]

The FSM specifies "normal" oil pressure as 13 psi minimum at idle, and 37 to 75 psi above 1600 RPM. My experience has been that most (other than very high mileage engines) seem to run between 50 and 60 psi at highway speeds.

[ZombiE]

Hey Shiny,

I replaced my oil pressure sending unit because that happened to me also. I've done every oil change on my rig and I just wasn't paying close enough attention and I went to loosen the filter then I heard a 'CRACKKKK'. Well I'm more careful now :)

Anyway to the point, I went and bought a new one from Autozone and mine also is reading higher that the Stock one did. Not out of the range the Service Manual says it should be but about 10-15 PSI higher. Just as long as I can see there is oil pressure I'm fine with it. I even went back to Autozone and had them look up the part # again. THey gave me the right one the first time. I just thought it was unusally high.


What year Jeep do you have?

Alex

[ShinyXJ]

I have a '93. From what I remember, the gauge usually spikes when I start it up and then settles around 60. I don't remember ever seeing it in the middle (40 or so). If it matters, I've been running full synthetic for about 4 years now. Would that affect the reading? Would the brand of filter afect the reading?

[railroadjeep]

I've been baffled by this too. My 89' when cold will run 60 PSI, period. Once warmed up, above 1,000-1,500 RPMs it'll stay at about 40-50 PSI and drop to about 30 PSI at idle.
This all became known when I replaced my sender, the old reading were about half that, and I have about a 1yr old engine in now (rebuilt). Up until 3 months ago I was also running 10w40 GTX, last oil change I went back to 10w30 GTX to try and bring the pressure's down a little, nothing changed really, maybe a few PSI.
Basically, I figure as long as I'm reading any sort of pressure over 10 PSI I figure I'm okay.

Chris

[Eagle]

Originally posted by ShinyXJ
I have a '93. From what I remember, the gauge usually spikes when I start it up and then settles around 60. I don't remember ever seeing it in the middle (40 or so). If it matters, I've been running full synthetic for about 4 years now. Would that affect the reading? Would the brand of filter afect the reading?

Full synthetic retains its viscosity better when hot. That was one of the two reasons I switched to synth at 175,000 miles. My oil pressure on long trips (on conventional 20W50) was dipping below 40. Still technically within spec but not enough to make me feel comfortable. I now run Castrol 5W50 and the oil pressure on the highway stays between 45 and 50. I'm now approaching 239,000 miles.

[Jay Welch]

Synthetic is great stuff. I run it in anything that I really care about including my John Deere garden tractor.

Have you ever compared the electric oil sender reading to a mechanical gauge reading???

Just curious because on my '89 the mechanical gauge read higher than the stock electric sender and gauge..

Jay in MA

[jeepster1985]

Its a mystery to me too my '96 xj always seems to be somewhere around 6opsi