2003 F12-X

OIL warning light/alarm beepping.

1) Oil /Filter NEW (Castrol 10w30 Synth)
2) Oil level checked (Front / Rear)
3) When idling.. BEEPS / Warning light
4) Immediately after started 1500+ RPM NO BUZZER/NO LIGHTS
5) Above 6000 RPM (not WOT) BEEPS / WARNING LIGHT.
6) After reset ignition it starts and runs same the way. BETWEEN 1500 / 6000 RPM it runs perfectly fine.
7) LOW / HIGH pressure sensors replaced.

I'll check oil pressure today with analog gauge. +/- 3000 rpm with warm engine.

Any advise?
I use SAE 10W 30 Synth after oil filter / oil replacement. Should I go back to 10W 40 instead?


Thanks!

PD: Hard to find High pressure sensor at local dealers here in CA.... It's the same as HONDA/ACURA VTEC oil pressure sensor 1992 - 2000+ online for $20.-