I have a 96 maxima has anyone had trouble with their tachometer i’ll start the car and the needle goes up to 4000 RPM automatically and I know it’s not running at 4000 from there goes all the way up to 8000 RPM even if I’m at idle Any help would be greatly appreciated

 

I've got a similar issue, recently the tachometer will jump way up, even peg at 9K, right after start. It continuously reads high and is very unstable.

 

Very common in these cars. Mine is currently unresponsive at any operating condition. I just choose to do without.

 

Our speedometers break down because the solder joints break where the mounting screws are.
Re-soldering the joints fixes it.

I suspect that our tach has a silica problem, and a similar repair might help.