I heard this directly from a BMW mechanic at a BMW CCA meeting...... and it changed my mind on buying a 4.8i
Very common issue.
Here are some other posts about it:
http://www.xoutpost.com/998656-post9.html
http://www.xoutpost.com/bmw-sav-foru...ml#post1008817
Maybe you can use the same show the guy in the post used to get it fixed cheaper when it comes up again.
Good luck,
Adrian
P.S. Thank you everyone in the Xoutpost universe for sharing all this valuable knowledge. Much appreciated.