I just bought my first BMW - used - in May of this year. I've been having this problem with the RPM's dropping 200-300 RPMs at idle. At first I thought it had to do with the compressor kicking in - to test this I ran it with/ without AC on. No real correlation. I have had it happen almost constantly on a daily basis, while at other times it runs smooth without hiccuping at all. It gives a very strong "bump", as if the engine wants to jump in a gear... Passengers feel it too and question me and I have no answer for it. I had the car checked by an independent BMW mechanic - he only works on BMW and was a master mechanic at the dealer I bought the car from for 8 years prior to starting his own business. I hadn't noticed this "" RPM bump" then - I had just bought it. The car seems to run fine once it gets moving - smooth and quiet, even when driven all day on a 300 plus mile trip - in fact, it ran the smoothest idle that whole day - it never did it at all. I'm wondering what to make of that - but it's intermittant excepting that one day and shorter trips ( 100-200 miles have also had the " idle bump"' Any idea what could be happenning? All systems say "ok" on the Nav screen under Vehicle info and other than this, the car seems flawless after I replaced the rotors and brake pads. I love the car - most fun I've had driving 42 years - should I be worried though and get it checked even though in all other respects, it seems fine?
There is a bulletin that describes you issue. During the engine warm up phase the idle will dip down. This caused by a software issue in the vehicle. To correct your DME would need programming. First you should check your software level it needs to be 12-07-508 or higher if not then it needs the programming.
Thanks for the quick reply to my post. How do I check this software level ( version) and what is the DME? Is this something I ask them to tell me at the dealer? Is there someplace online to see this bulletin you refer to or is that something I need to request? ( from dealer? From another repair shop? From BMW?) Thanks again for your reply - a software issue sounds much better than what I was worried about - I'd like to check this possibility out.
The easiest way to check your software level is to have the vehicles key read at the dealer and they would be able to get you a print out with all that info on there called a key read. The bulletin is internal to BMW but your indy might have a way of looking it up. Since your at the dealer you can ask them if they would get it for you but they might say no since it is internal to BMW. Let me know how things work out curious myself.
