I've just been overhauling the vanos system on my '07 E93 325i due to intermittent vanos error codes.
For info, a light "lifter tick" that's been present since I got the car disappeared after I cleaned the vanos check filters, the good news is the job costs nothing and takes less than 30 minutes
Something to think about?
https://www.e90post.com/forums/showthread.php?t=900394