Rep Power: 118

Hello everyone, I just got done installing an oil pressure gauge in my 05 Civic, and I am a little bit concerned by my oil pressure. On a cold start it will go up to 80-90 PSI at idle, which seems fine. Holding it at 3000 RPM after the oil is fully warmed up (180 degrees), the oil pressure runs at around 70 PSI. Again, seems fine to me. But I'm a bit concerned about the oil pressure at idle. Once the engine heats up, it's only making around 11 PSI at idle (~750 RPM). If I raise the RPM to around 1000 it will make around 25 PSI, which seems alright to me. I just don't understand why it's dropping down so low at idle. No glitter in the oil, no concerning noises, and the oil pressure warning light never comes on. Is this something I should be concerned about, or is this normal for these engines? Thank you very much in advance, I really appreciate your help.

 
Rep Power: 224

Service manual states oil pressure at idle should be no less than 10 psi (oil temp at 176F) and at 3k rpm no less than 50 psi.

 
Rep Power: 118

Cool, thank you! So no need to worry, or is that too close to the lower limit for safety?

 
Rep Power: 224

It's within spec, I wouldn't worry about it.

 
Rep Power: 118

Cool, thank you so much! At what pressure should I become worried? I know the spec is at 176F, but when the oil gets hotter than that my pressure will drop further, likely into the single digits. But I presume this is okay since the pressure is within spec at the oil temp the specs are given for?

 
Rep Power: 367

Already answered

Also, have been using pressure gauge for many years - thats normal.
you simply did not know until you installed gauge

 
Rep Power: 367

1989 Mazda miata came with full oil pressure gauge, many customers complained that the pressure looked low and Mazda had to change that to a idiot light type, full on or off because of customers that did not understand engine oil pressure.

 
Rep Power: 118

Cool, thank you!

 
Rep Power: 118

Good point. From my understanding, a lot of vehicles with factory oil pressure gauges don't show true pressure for the same reason. Instead, the ECU receives the data from the pressure sensor and if it deems it acceptable for the current conditions the gauge on the dash will read near the middle, and if it doesn't it reads all the way down into the red. And the variations between idle and high RPM often look much less dramatic than they really are. The gauge goes up some with RPM because that's what people expect it to do, but really it's often no more useful than an idiot light.

Actually the stock temp gauge on these cars operates in a similar way. It doesn't show true coolant temp, just cold, normal, and hot. Between about 160 degrees and 230 degrees it doesn't move.