recently, i found that there is only one rubber O-ring with the oil filter for E60 M54 2004 525i, instead of two(one big ,the other little). am i right, every body?

 

i have found the same question and its answer on the thread https://5series.net/forums/diy-do-yo...-49786/page11/, page 11,#104,#105.some one else has ever met the same situation.

 

Your M54 oil filter kit should have:

oil filter
oil filter housing cap seal (big black o-ring)
copper drain plug seal

There really is no need to replace any seals other than those two during a routine oil change.