I was driving my '07 GT one last time before putting it away for the winter today, and after my drive I stopped with a quarter tank to fill up in preparation for storage. After pumping approximately 12 gallons in the needle only went up to just over a half tank and stopped. When I got home I shut the car off and then restarted it to see if the gauge would show full after cycling the power, no luck, it came up to half a tank and stopped again!
Anyone else had this problem? If so how was it fixed?

 

Sounds like a bad instrument cluster , a lot of us have had them go bad. Do a search there's a lot of info ...

 

You might try a 20 oz. bottle of Chevron Techron and fill (I would use preimum gas) and run until almost empty. If the first tank doesn't fix it, run a second tank of straight gas through and then follow with a second 20 oz.bottle of Techron & preimum gas & run until about empty. This is a known problem caused by sulphur in today's gasoline. I have read Ford recommends this procedure. Good luck.

 

its the fuel sending unit on these cars. they stopped using gold and started using silver in them and the sulphur clogs the unit.

my old 2006 mustang went though 3 of them under the tsb.

 

Switched gas from Chevron to BP fixed the problem. But it does freak you out when it happens...