When I had mine done the SA advised that is will NOT cause more damage if left unfixed. Plus considering you have gone 35K miles with the issue on and off I tend to believe this.

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2005 BMW X5 4.4 Sport Upgrades:

Dinan Cold Air Intake
Dinan Stage II Software
Akebono Euro Cermaic Pads
Brembo Rotors
Titan Silver Metal Gauge Rings
DICE IPOD Module
Hardwired Passport 9500ix Radar/Laser Detector