Indicated oil pressure

[par]

I've been noticing the oil pressure slightly outside of the upper end of the high limit at full power on T/O. I'm dead center in the green at 1700RPM during run up. In flight, it indicated in the higher end of the green arc. Once the engine is warmed up, I show right at the lower end of the acceptable range at 1000RPM. Is any of this unacceptable?

[N201MKTurbo]

Sounds about right. If you use a multi weight oil you will see less variation between cold and hot.

I always adjust the pressure regulators so they are at the bottom of the green arc with a hot engine.

[DXB]

Yeah I notice somewhat similar fluctuations too, definitely more pronounced when I switched from 15W50 to 100W for the summer months.

[cliffy]

When was the last time any cockpit oil pressure gauge was calibrated?

Sorry to disagree but I'll bet not often-

electronic after market systems aside. Setting to a cockpit gauge may not be near where

the pressure is supposed to be. The correct pressure is called out in the overhaul manual

and should be set with a calibrated gauge tied into the oil pressure port on the engine.

It's that important.

Think about it for a minute- could you make a log book sign off saying "reset oil presssure

to the bottom of the green arc" ?

You might find that your Oil Pressure is correct and that gauge needs calibration by doing it correctly.

[MB65E]

Have your tech verify what the engine is doing on the ground with a calibrated pressure guage tied directly to the engine oil port. These older airplanes have all sorts of differances after the oil port fitting. Different gauges, sending units, goofy grounds, wiring messes. It's nice to know what the engine is doing first, just to see if the guage is reading high or low. Mine had a 201 panel with the Rochester stack in it. Guage read to 100psi, but the sending unit was the incorrect PMA'd part. It was actually reading low. I put the correct sending unit in to match the 0-100 and now the guage reads high. However, I know from my testing that the engine is right where I want it at 78psi verified/calabrated. It's maybe 10psi higher on the guage itself. I was really tired of the silly thing, and left it alone. One day I'll do a stand alone electric EI oil temp/pressure guage.

-Matt

[Guitarmaster]

I've been noticing the oil pressure slightly outside of the upper end of the high limit at full power on T/O. I'm dead center in the green at 1700RPM during run up. In flight, it indicated in the higher end of the green arc. Once the engine is warmed up, I show right at the lower end of the acceptable range at 1000RPM. Is any of this unacceptable?

 

Put a manual pressure gauge on it.  My cockpit indication was off by 20psi!  

[par]

My gauges def need some rehab so i'm sure part of it has to do with that. Look's like I'll have the shop check it out next month so I can be sure.