Yes.. the oil level moves up and down (liquid ma..) depending on condition and of course, the leveling of the ground. Perhaps your oil level is 0.23L short, so it still show full sometime and a quarter liter short sometime which cause the indicator to show short one bar.
Also bear in mind that your oil pump not on full time, its condition based. So taking reading when the pump is resting versus when pump is running should gives u some difference in oil level reading.
Unless it fluctuates between full and short 3 bar, then you should be worry of faulty oil level sensor because the movement is a little too drastic.
