I had the same problem X5Dawg had. Low oil level for some time...very low. My X needed 5 quarts to bring it up to full. So the question I asked myself is why didn't the "check oil level" warning come on? My guess is its prob a bad sensor. Iv searched the forum and couldnt find anything on it. Does anyone know where its located and what the technical name of the part is?

Thanks for your help

2001 E53 3.0L 109K