I just replaced the fuel filter in a 2010 e60 with N52k. It had 50,000 miles on it.

I noticed two things I think are unusual.

The weight of the old filter was noticeably heavy. OK, I drained the has out of the filter and I know the filter still might be wet, but its still unusually heavy.

Is that because there is so much dirt in the filter its making it heavy?

Next:

Once the new filter was installed there is a loud sucking sound coming from that filter that was not there with the old filter.

 

Well, if you hear sucking that could mean an air leak - check filter connections and fit. Was it just once the first time, or every time/ all the time?