Speedo issue

[davidrbroder62]

My 1997 Z3 has an issue with the speedo and I was hoping someone could help with some advice. When I drive, sometimes the speedo needle just lays there. Other times it jumps to 80 KPH even though I'm crawling in traffic. Might this be a cable issue? Does the Z3 even have a speedo cable?

 

[Andybpowell]

Not 100% sure but I think they are all electric not mechanical

 

[Andybpowell]

So would say it's cluster related the sensor in the diff should not be able to cause the issue you are having