You tried loosening your gas cap and it made no difference in your situation?

I removed my locking gas cap and went back to the regular gas cap. My fuel filter is always full now, even after a 30 minute drive and some burnouts. And I can open the hood now without the engine heat burning off my eye brows! The locking gas cap would not let the tank breathe properly. Engine could not get enough gas, so it went lean and engine temps rocketed up. Same thing could happen if your tank vent were to be clogged.