About a month ago I purchased a 2003 Cavalier for my daughter with about 75,000 miles on it. At first all seemed in very good condition but in the last week one problem has occurred a couple of times. The fuel gauge has started to read way over full to the point that it interferes with the temp gauge pointer. When starting the car all the gauges go to full reverse and then go to their proper position. When this first happened I though that it might be a sulphur build-up on the float and I added a can of Techno to the tank to see if it would fix it. Problem got better in a couple of days and I thought "Lucked out here". But this morning it returned. I put the car on ramps and checked out the wires both for clean contacts and also to see if any might be broken by pulling on the connections. Nothing helped. I thought maybe the float or internal connection were bad and that I would have to pull the tank. Here is where it gets odd. I started the car in preparation for getting off the ramps. It seemed to me that the gauge wasn't as far out as it was at first. So I did it again. Better. Again, better. After 8 starts and short runs the gauge then read about where I expected it should with the amount of gas in it. Does anyone have any ideas about what might cause this or experienced it in your car? Perhaps a gauge in dash problem? Any advice appreciated. Thanks.

Check the plug on the back of the cluster, also check your ground wires for corrosion issues or for being loose.

Dave

agreed. could also be the gauge cluster. cluster suck in j's so that could also very likely be the culprit. if you decide upon a gauge cluster i have on i will sell you for 30 dollars plus shipping. froom an 03 cavalier

Thanks guys. I will check it. I will let you know about the cluster Wojo. Thanks for the offer.