In my E90 I had a similar/same issue. Took out the blower and added some lube to it (The shaft portion) and it went away. Not sure if the same can be done for the E70, but I dont see why not.

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E70 LCI 35D

E90 LCI 328i xDrive
E39 '00 528i Sport/5sp
E28 '88 535is
E84 35ix M packaged
E38 '01 740i Sport
E39 '02 M5