boost and oil pressure gauges help

[Brodtz]

so i just bought a subaru wrx. it has boost gauge and a oil pressure gauge, it was running low on oil so i put new oil in the car.
it was running around 80-90 the entire time (idle or getting on it) when i put the new oil in it stayed high then dropped a bit, turned off the car for a couple hours and it was back high. is this because the engine isn't warm? HELP!

[shadowpr]

during idle, when the car is cold the oil pressure will be around 90psi or so.

as it warms up, it should lower to around 40psi or so.

while driving, even warm, the pressure will increase and be around 90.

[MainFrame]

At idle with the engine warm oil pressure should be between 10 and 20psi. It takes about twice as long for the oil to get up to temperature as the coolant. Drive the car for 30 minutes, then see where the idle pressure is. If it is still excessively high, I would guess that the gauge is not reading properly.


The oil pump turns with the engine, so as RPM rises the pressure rises. Around 20psi at 1000rpm -> 90psi at 7000rpm. At 3000rpm it should be around 40-50psi. As long as it isn't dropping below 5psi you're fine.

[Brodtz]

thank you!!