I have a 2001 monte carlo ss and the fuel guage will bounce all over the place. The only way I can tell how much gas I have is by using the digital display and look how many gallons I have used. Any ideas why the guage will move around as I drive down the road or park on a change in grade???

 

possibly it could be a fuel tank sending unit, which most likely (when i get to work double check) come with the fuel pump as well, which means it could be a biiiiiiiiiig dollar fix.

thats most likely a worst case senario, but it could be that

 

easy way to find out id go to a bone yard and find a guage pod and replace yours for a few miles to find out if it stops.

but i owuld check the groud etc... first..
or call a dealer if you get in tight with one of the guys behand the contrer they can sometimes tell you what it might be also.

 

Probably the sensor on the fuel pump in the tank. Had the same problem on a buick century. Just went to the junk yard and got a used fuel pump assembly for $40 and it works like a charm now!

 

sitting here thinking of this. if yoru speedo is off also i would defently check in to a diffrent pod.
thinking of this it is a whole unit in there it is not seperate guages. So with that said it could be that hte bread bord is goign bad and it is showing this in more then one guage. So the speedo is off and the gas needel is bouncing.