[TassieBMW]

The other day I accidentally overfilled my 330i by around 1 litre. Yes, I know, I should have been paying more attention. The computer didn't actually say it was overfilled but the car was halfway on the oil marker and I added 1.5 litres instead of 0.5 so I knew there was too much in there.

Anyway, I drained some oil (4 litres as I had to take the bolt out completely and by the time I put it back in thats how much had drained).

I did a level check with the engine off before adding more oil and obviously it said below minimum. I added 1.5 litres and checked again and it said oil level ok. So, I started the engine and waited for it to do a proper oil level test.
What's strange is it said the level was at max...? I checked using INPA and it was showing oil level to be 121/125 so basically full.

What am I missing here, or is the sensor faulty?

I sure didn't overfill the engine by anymore than 1.25 litres at most so how after draining 4 litres is adding 1.5 back enough to bring it to max.

I'm also a little worried as to what I should do. Do I add more oil, and if so how much?

[JB20DGM]

If you want to "be sure" then drain all the oil out and re-fill with the correct ammount.

[Brian86]

If you still have oil pressure: it's not overfilled.