It happened to me once...What i did was loosen or take out all the screws holding the lock/cap assembly on....Then try and turn key and if it was like mine....took some jiggling and came off...the lock was all gum'd up so a can of brake cleaner later worked like new
Pac - I'm thinking that might help - does KMart carry any lock break or break free specifically? Unfortunately, it may not be the key hole that needs to be lubed, it might be the lock itself try to drip lube all around the cap maybe some will get to the lock lugs. Worst comes to worst..... don't you know any lock smiths?
Lock break? I dunno. I don't think so. I'm sure NAPA or one of the auto stores should have. If worse comes to worse, I can check Ace Hardware.
I know a locksmith, but the problem is gettin the damn thing to turn.
If you look at the bottom of your gas cap, you'll see a hook on one end, and moving lock on the other. If you take out the screws, the moving lock comes out (be careful not to lose the spring) and you'll spy a drum with two teeth on it.
It's that damn drum that turns the moving lock. Either that thing got gunked up or there's some oxidation on the gas tank lip that's holding it.
I'm eyein that drum as the main culprit here. ANd I'm gettin pissed with it.
Time to break out that BMFH and whack a few things loose.