Some people might argue, but I have gone through 3 different independent "bmw specialists" in 4 years, all say the same.
Maybe you could change it every Inspection2 but on the diesel I think that is every 40000 Km or roughly 2 years. mines been checked by my guys each year. They put the same one back in.
As they are made to be like a "vortex" they should not get clogged. That was the idea of them.
Yours did look very oily though (outside and in).
Make sure you have the right oil level and check it as recommended (IE: go on a good drive to heat it all up. Park on level ground, wait 20 minutes, then check the oil level).
When I got mine 4 years ago, I did the same as you as I get nice black smoke when flooring it.. Didn't do any difference. People say that is normal.
Have to clean the soot out every now and again
