Georgio said:Have you got hill assist?
Sounds like someting to do with that if you have it.
Maniac said:I'd say issue with the vacuum line or associated components. Have a local indy check it over for leaks etc.
* Oh and its 'Brakes' not 'Breaks'![]()
Maniac said:There's another thread on here thats similar, only their idle went up not down. Worth a look though; http://www.z4-forum.com/forum/viewtopic.php?f=3&t=40500&p=568573&hilit=idle+replaced#p568573
Does the idle change only on the brake being pressed? What about if you put on all your lights etc? Idle drop here would indicate a voltage drain (alternator issue). If only when brakes are being pressed, it could well be something on the vacuum side. Perhaps only exists for the first few minutes while your engine gets up to running temp and is less affected thereafter.
bcworkz said:Unlikely MAF, IMO. Most likely as Maniac says. Vacuum leak in either brake servo hose or inside servo itself. A malfunctioning MAF could make the effect worse, but wouldn't be the root cause. Did you note the error code before you cleared it? Was it MAF related or are you speculating?

well thats understandable but someone might have had a siimular experiance and know what it me be/cost if they have had a vacuum leak in the past.Maniac said:As the leak could be anywhere, you'll have to take it to a professional to diagnose. No one here will be able to guess where the leak is and guess what it might cost, which if they did, would not be very helpful anyhow as your local garage/dealer may find and charge very differently to any guesses.