vacuum leak is driving me nuts!! need help plz
Hey guys, need some help here as im at the end of my wits, i have a '92 325is, with a serious vacuum leak as far as i can tell, causing the idle to move anywere from 600rpm to about 1400rpm. whats i cant figure out is the leak is intermittent sometimes idles alright, with only slight variation (between 100 rpm) soemtimes terrible (changing by 500- 1000rpm) all the hoses appear to be okay and its as if i can here it sucking in major air somewhere underneath the intake manifold, or throttle body plate, i was thinking possibly idle control valve, but i dont have enough experience or the money to just start swapping out random parts, has anyone experienced a problem like this? your advice would be much appreciated!