the tach in my car seems to be broken. pretty sure because the wot shift points keep climbing while the car hasnt been messed with. its up to 5800 rpm now from 5000. this seemes to be a common problem. what is the common fix. where is the tach going wrong and would a new guage cluster fix it . what should i do

 

Its either the capacitor on the board for the tach or one of the IC chips on the board. Best bet is to replace the tach.