1998 Z3 Speedometer Issues
 

I have a 1998 Z3, 2.8L with approx. 140k miles. During the last several years the speedometer will stop working while I am driving, then surge back into operation. If cruise control is engaged it disengages. Everything else continues to work, i.e. tachometer, lights, other gauges. While the speedometer is stopped I don't accumulate any mileage on the odometer. I have read about a speed sensor on the crankshaft and also bad solder joints in the back of the speedometer. Any advice?