I drove the car 2 days ago, and oil pressure was fine (1.5+ bar at idle, 2.5 low rpm cruise, and pegged 3 bar under load & higher rpm).

I started it today and the needle didn't move off the peg, 0.

It sounds normal. I backed it out of the garage to wash it, and put it away later. I checked the oil level, full. I removed the oil fill cap, the cams were wet and the bottom of the cap was too.

I will pull the filter tomorrow and see if it is clogged. It's relatively new. The oil is clean and clear.

I suspect it is 1 of 4 things:
- Electrical between the sensor and gauge
- Bad Sensor
- Oil Blockage at the sensor
- Bad Oil Pump/ chain / mechanical

I have a couple questions:
Is the oil side of the sensor accessible from the oil filter fitting with the oil filter removed (to see if its blocked)?

If there is a bad wire or sensor, will the gauge default to 0 bar, or 3 bar?
(The sensor has the 2 wire snap type connector on the back, and the wiring diagram shows 3 wires at the gauge; pwr, gnd, signal). Will absence of the signal pin at 3 bar while absence of power stay at zero?

If it is something more serious, like the oil pump, are there any tell tales to look for before pulling the oil pan off?

Thanks in advance.