Skoda Octavia 61 plate 1.4 Tsi low oil pressure warning light

Ive been having an issue with oil pressure light coming on.

I changed the oil and filter, and the light went away.

After this is changed the turbo actuator as i was also suffering underboost. After this replacement the car drove well with no under boost, this problem is now fixed. 

After a few weeks, i put the car on a ramp to check for a coolant leak, now after leaving the car on the ramp, it decided not to start. The car would crank but not fire up.

I rolled the car down on the ramps, car wouldn't start. I left the car overnight and hey presto it started. Later that day, the car would not start, cranks but no joy.

While attempting to start the car, the cranks and then the oil light appears. Its the red oil can light to do with pressure, im not getting any fault codes.

I have since taken off the sump to check that, it looked clean enough, no debris. Ive checked the oil pick up pipe, again this look fine, not sludge or blockages. 

Ive just ordered a new oil pressure sensor and oil pump.

Does anyone have an idea what is going wrong??!