oil pressure

[fendermb4]

A week or so ago I asked about my oil pressure, here: http://www.comancheclub.com/forums/view ... highlight=

 

Well, I got a mechanical gauge, hooked it up, and found out that my pressure isn't low at all. Its high. The mechanical gauge is reading 55 psi at idle. I just changed the oil. I used 6 quarts of castrol 10w30 to set a level field and got the same results.

 

Like I said in my other post, my 99XJ sits at 30-40psi - 55 seems too high. Is it? What is normal for the Renix? What could be causing high oil pressure? Could this be related to the unreasonable amount of oil that wants to come out of my PCV system?

 

For posterity, Eagle was right. I had measured the pressure when the oil was cold, so it was a bit higher. Once the truck warmed up, the pressure was around 40psi, which is right where I wanted it.

[ROADLESS]

The FSM states that the normal oil pressure should be 13 psi @ 600 RPM or 37-75 psi @ 1600 RPM :yes: .

[Eagle]

The factory specs are for a hot engine (normal operating temperature). Did you take your mechanical readings hot, or just after a cold start? 13 psi is a factory minimum and most 4.0Ls idle around 25 to 30 psi, and most in decent condition run about 50 to 55 psi at normal (within speed limits) highway speeds. Your idle pressure sounds higher than normal, but if you measured it cold you're comparing apples to pomegranites.