hello i have a 01 ml 320 with about 120k. my tachometer acts up often. it stops working, and it slowly goes up n it will stay up. sometimes when i hit the dash right over the instrument panel, the tach starts working, but it shows the wrong rpm. when i turn the car off after hitting it the gauge goes down and it usually works for a couple days after that. but sometimes hitting wont work either. has anybody seen or heard of such an issue?

 

never seen that issue. most likely a new cluster will be needed. maybe you could try to clean it with some computer board spray. or compressed air. but you will have to disassemble the cluster. which i never tried to do so I cant give you any pointers on that