Exact thing I did twice but the second time I added less and didn't have to drain a quart!I'm adding to this thread just to contribute in the hopes that my mistake in not reading this threat will save someone else from this hassle.
After getting my oil changed about 60 days ago, the oil reading dropped from the top arrow on the oil level display on the dashboard, to just above the bottom. I added 0.75 liters and didn't see it move. I drove the car for a couple days - it didn't budge. Hmm. I added another 0.5 liters and didn't see it budge after about two days and 20 miles so I stopped by BMW Bellevue to ask. I had a few occasions over the last three months, prior to a battery change, where the readout was empty, so I thought it was a faulty sensor.
Turns out, as you are no doubt seeing, that I did not push the stalk button and let the oil gauge reset. I reasoned, erroneously, that since is drops when the oil goes down, it would raise when oil was added. Silly me. After resetting the gauge it showed "greater than Max" or ">Max". The idrive showed the oil in yellow and indicated an overfill.
They didn't something with the filter to drain some and got it down to exactly at the top arrow indicator for "okay", so I'm good to go. It was a $150 lesson (plus the wasted liter of oil), that maybe this thread will help someone else avoid.
The SA and mechanic emphasized that overfilling the engine, as already discussed, is a no-no. I forgot the tolerance, but I think it was about 0.25 liter.
I now know to reset the oil reading!
Thanks for your post!