rubber hose M20?

[cro320]

I need to replace this rubber hose number 3
is this related to vacuum control or something else?
I noticed it's cracked a bit

http://www.realoem.com/bmw/showparts.do ... g=11&fg=15

[TouringTash]

just had a look in my haynes and can't make out what it connects to I take that its for an M20 engine?
will have a look at a 320 lump in the morn

[bilun777]

As the picture says it's just crankcase ventilation, from the rockercover to the throttle body[If you're worried just wrap a bit of electricians tape around the crack for now]

[cro320]

Needs to be airtight or you will get uneven idle and incorrect mixture. Is the crankcase ventilation pipe.

OH, will order it today
probably that's why it runs rough when cold