Welcome to the club. I must have said this three times already to others.

Check you Throttle Body (that was the case in my case)

By the time you hit a 100k you should expect following to fail:
- throttle body
- rear air springs, unless already replaced
- alternator
- valley pan gasket seal or coolant exchange pipe seal (that will require valley pan removal
- alternator bracket gasket
- valve cover gaskets
- timing cover gasket

Here was my experiance:
http://www.xoutpost.com/bmw-sav-foru...lfunction.html