RPM trouble

rpm

#1

my rpm gauge is going crazy. it is running higher than normal, but the engine is staying the same. what is causing the rpm to move like this. also when i turn the car off, the rpm gauge goes all the way to the hgihest number, it use to go to zero


#2

my rpm gauge is going crazy. it is running higher than normal, but the engine is staying the same. what is causing the rpm to move like this. also when i turn the car off, the rpm gauge goes all the way to the hgihest number, it use to go to zero


#3

car, engine, mileage?
So the tachometer is reading incorrectly? In modern cars, the tach is fed by the computer.