Yes Vanos is a variable timing that can and will go bad after a while-in the 99 to 01 models and up they are doulbe vanos-one for intake cam and one for exhaust. Seems that the orings in these suckers go bad after a while especially in colder climates-the only fix so far is at the stealerships and it ain't cheap. 6-800 or so-not a DIY'er as of yet-gotta have cam tools to make sure everything is right-BMW is aware of the problem and it happens frequently-about the only thing thats really bad about these 6 bangers. Before 02 years are the ones that this is happening to and it's not limited to the 6 cylinders-some of the 8's have had trouble as well-great cars lotsa power and wants to cruse at 90 on the interstate-be carefull if ya buy one. I love mine but if the 960 Volvo came back I'd buy me another in a heart beat-lot easier to work on-The BMW cooling system need to be overhauled at about 100k mile-rad-water pump theristat and housing belts and hosings-looking at about 5-600 if you do the job yourself.
Poolman