There isn't a timing belt, the M54 motor uses chain to drive the camshafts. Maintenance for the car is spelled out nicely from the manufacturers, follow it and you should be good to go. 100k is not excessive, unless the car was abused, therefore I strongly recommend a pre-purchase inspection by a BMW facility to bring any issues to the negotiating table.
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Thursday, June 3rd, 2010 AT 8:44 AM