Vaccuum Leak

[tico481]

How can I tell if my car has a vaccuum leak??

[Speedy-325is]

Hissssing noises r a big clue

use a can of starter spay(carb cleaner works too) and MIST, dont hose down, the area u wish to test. for example if u want to check for craks in a vaccume hose, lightly spray the hose w/ur car running in idle. when u spray, step back and listen to the engine/RPM'a for a change/rise in sound. if the rpm's rise, u found ur problem. if no change, then keep searching.

the hose connections where the hose clamps begin to crack up sometimes, so there can be hard to find cracks after a while.
Good luck
Mark

[tico481]

I feel like an idiot asking this, but where is the vaccuum hose located?

[thekid]

If you have a 318i then the hose behinde you engine up near the cowl piece has a tendancy to crack, also the hose going from your FAMS to your engine is also one that likes to crack. If they are cracked you should be able to see it, but you may have to check both sides of the hose. Also you may get an engine code from a vacum leak.