Nevermind, just talked to Bavarian Autosports, they said it could also be the resistor on the Aux Fan, very common problem. I think the mechanic is wrong. Thanks for your help.

__________________
___________________________
2005 BMW X5 3.0i (Current)
2000 Toyota 4Runner (sold in 2011)
Formula 1000 - Van Diemen/Novak (sold in 2011)
1989 635csi (sold in 2008)
1985 BMW 325e (sold in 2006, but never forgotten)