Weird one this.
Started car up tonight, no problems, oil pressure reading in usual range. Made a journey of about 8 miles, shut the car down, went into a shop.
When restarting, oil pressure was showing about 80psi at idle. Above 2000 rpm its offscale (>120psi). Showing 60psi with the engine off, which is really weird.

My first thoughts on this are the sender unit, cant think of any PCV or drain valve that could be stuck in the wrong position holding the pressure at that kind of level.

Any thoughts???

 

How 'bout taking the sensor out and turn the key to "on" to check the reading with the sensor open to ambient pressure?

If it reads zero at atmospheric pressure, then maybe your pressure inside really was that high.

 

Gauge just reads offscale all the time with the ignition on, now. Another thing for the dealers to fix