I have a 2005 Sunfire with the EcoTec motor.

A few days ago, my temperature gauge moved through the red zone and all the way into the path of my RPM gauge. There is nothing wrong with the car (I checked), and the temperature guage is bad (would be my guess), but it has now moved my tach so that it is about 1,500 rpm off (it will not go back to zero).

What do I do? Do I have to replace the whole gauge cluster, or is there a way to remove the cluster and reset?

I hate to spend the money if there is an easy fix.

Any help would be appreciated.

I wouldnt be so sure there is nothing wrong, but you should be able to "reset' the gauges by turning the key to run and then back off several times.

I have checked everything, and there is nothing wrong with the car itself.

The temperature gauge is now completely pegged at the bottom (as far as it can possibly go).

From a little research I have done, I guess there are little stepper motors on the back of the gauges that can go bad and have to be replaced. Has anyone done this, and how difficult is it?

I had the same problem with my speedo. The only way to fix it is to replace the whole gauge cluster. I got a brand new one off ebay for about $40 bucks shipped. It is a very easy fix, but takes some time as you have to remove the dash. Somewhere on this site is a walkthrough. Or you could add an aftermarket water temp sensor, but hey. Hope that helps.