Driving home from work and noticed the engine note seemed a lot deeper in the cabin than usual. I have no foam in the sound generator so it sounds pretty loud anyway, but it was even louder than normal.
Upon inspecting the air intake area, I noticed this pipe was cracked:


Would this be the likely culprit? Also, is that part number 5 on here?:
http://www.realoem.com/bmw/showparts.do?model=BT52&mospid=47797&btnr=13_0995&hg=13&fg=15&hl=9
Upon inspecting the air intake area, I noticed this pipe was cracked:


Would this be the likely culprit? Also, is that part number 5 on here?:
http://www.realoem.com/bmw/showparts.do?model=BT52&mospid=47797&btnr=13_0995&hg=13&fg=15&hl=9