In an attempt at trying to get to know my machine better I learned how to change the oil from the comforts of home yesterday. Besides a couple of little issues (like making sure that if the front end is jacked up, you'd better have the back side jacked up as well or else the oil will dribble into the belly tray) it was quite easy! My concern is this, the oil change kit had 7 quarts. After reading a few online ideas, I did the standard but 6 in, drive around a few blocks and see if it needs more. Of course at first it said "OK" and was to the max line. After 100 miles (50 of them aggressive twisty bits at top speed) the sensor said that I'm between max and min but still "OK". Just exactly how "OK" is it, should i fill it up with another 1/2 quart to be at the max line. From what I understand it won't tell you you're low until you're an entire quart low, which seems kind of drastic. Am I being paranoid? (PS - had anybody else crawled up under the front end of their One Series and found that there is a random place in the belly pan where a bolt looks like it should be but doesn't go to anything?)
BMW seems to have fiendishly designed ALL of their recent engines to require just about 6.5 quarts. On the roadster's S54, it's easy to see by checking the dipstick, but you don't have one. Without being a Certified Master Technician (or even playing one on TV), I'd say adding another half-quart will not harm anything, and may get your sensor to read full again.
On a 6.5 quart system, a quart down isn't normally a problem. The engine will probably do fine two quarts down. Most that I've seen (that lost that much) didn't even suffer with half the oil MIA.
The tard now has a full belly of fully synthetic. He's a happy old chap, anticipating track day coming up.
