It looks like it can be one of three things causing the problem (if the car is level and has the correct oil level).
1) Bad sensor on the engine.
2) A problem with the wiring between the sensor and the indicator.
3) A bad indicator
*The Bentley manual states that if there is a fault in the oil level detection system (broken wire, or short to ground) the entire display flashes.
With an intermittent problem it is most likely the wiring.
Here's the connection to the sensor on the engine: (
Blue arrow)
Looks like a pain in the @ss to access, but I would pull that connection and give it a good cleaning and visual inspection.
The sensor is available for about $80 new. I'd grab one off a dead engine and swap it in there if the connection/wiring looks good. (Lucky me, I have a dead engine.) Ask in the classified section, I'm sure there's some used ones available cheap.