Oil pressure falls as rev goes up once the engine is warmed up.
 

My idle oil pressure is at around 60 psi. When I rev it to 3000 rpm while the engine is cold, it maxes out at about 100-110 psi. This all looks normal.

I have noticed in the last few hours that my oil pressure is somehow falling with high RPM especially when the engine is warmed up. When I rev the motor, it goes as low as 40 psi. Idle is always normal at around 50-60psi. When I rev the motor, it climbs to maybe 80psi at about 2500rpm then starts to fall at around 3000rpm and continues to fall until 5000rpm+ to minimum of about 30-40psi after which I let go of the accelerator. My initial search seems to indicate crack in the pick-up tube and/or tube gasket/o-ring, but I haven't done anything. I have just about 200miles on the motor. I just changed the filter and oil to 15-50w mobil synthetic. It's the same thing. When it's cold, it's fine, but as it warms up, pressure falls as rev goes up.

Any ideas?

is the gauge by any chance prosport? my prosport gauge is crapped out and my pressure is all over the place on there.

At Idle im at 150psi when i drive it drops to 60 jumps to 90, you get the idea

Might be best to try a different gauge before looking at the mechanical side, unless you are sure your gauge is fully functional

Might want to mention you are talking about a 20B :)

And yes, how are you reading oil pressure and from where?

I'm reading from a Defi gauge. I'm not sure if it's faulty sensor just because how it's acting. It's predictable and based on engine rpm. It's little PIA to get to pressure sensor area, but I'll try my mechanical fuel pressure sensor and see if I'm getting the same reading.

Yeah I would confirm with an oil pressure gauge at the factory oil pressure sensor location on the engine. I would not drive it that way, low oil pressure will kill it dead with a quickness.

whilst i cant say if your gauge is faulty the same way as mine, but mine always goes in exactly the same pattern, 150 psi, on throttle drops to a certain psi, climbs, then 150 psi on idle. Unless im really on 150psi on idle O.O

60 PSI at idle seems extremely high, I am comparing to an NA renises. I am at 20-30 at idle and max 110-120 around 8K

60psi(4-4.5bar) is just about right at idle warmed up. That's how much I have using a auberins digital oil pressure gauge. Don't know what Tofu is talking about with 150psi on idle, sounds like he has a different problem.

Tofu is comparing a 20B to a 13B, its irrelevant

nah i aint comparing the two motors or the pressure, im comparing what my pressure gauge is doing since it does not work at all and gives me ridiculous figures which i know is not true. From the op description of how his gauge is acting it just sounded similar. Thought i'd point out it could be a issue with the gauge it self or the sensor.