tick over speed
 

my car flucuates between 900 and 1500 rpm. I thought it could've been down to a dirty air filter, which i have replaced.
Still getting same problem. Any ideas?

:dunno

check all your vac lines for cracks. (Including bellows tube) Could also be fuel issue (sticky injector) but I'd check the vac lines first.

cool, i am new to bmw's. is there a how to for vac line checking and for sticky injector checks???

:)