A clicking noise has developed on my 99 100 which seems like it is coming from the inst. cluster or maybe higher/closer to the front window. It ONLY clicks between idle and 1700 rpms in any gear (Assumption. I used the 2nd gear take off to see). AND it will go away after about thirty minutes of driving i.e. drive to work and at idle you cannot hear it. It is significantly loud and reminds of the sound of old mechanical speedos when the gearing became stripped. No issues with any of the gauges. Any ideas? Thanks.