If you've got the older crankcase breather then it's sure to be blocked causing the crankcase to pressurise forcing oil up the dipstick & you'll never get an accurate reading. This will eventually result in the turbo blowing so you'll need to fit a new breather, preferably the BMW only modified vortex part.
my Td4 auto was exactly the same when I bought it nearly 4 years ago but it's fine since the breather was done.