My 2007 S-type 3.0 gas tank cover won't stay closed. It's been closing/locking fine. I got fuel yesterday and closed it. However, by the time I got home, it was opened again. I thought it was a fluke. But, alas, this morning it was open again. This time when I close it, it immediately opens. I am NOT going to pay a mechanic $100 or more for something that may be a simple "fix." Any suggestions? ----Thanks

 

Not much of a fix but lubrication always helps. Most people end up getting them replaced because there is a plastic pin or catch that is easy to damage.

This is a good reminder to the rest of use with working gas flaps. Get out there and spray some lubrication on the latch right now!!

I have heard of this problem for years. I started way back then to hit the fuel flap with a shot of Lithium grease every once in a while. After 6 years and 106K miles it still works perfectly.
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Yes - use lubricant.
On my 2007 S - 50% of the time it won't stay closed. When gassing & before closing the flap, look to see that the plastic "pin" is fully extended. If not - while the gas flap is open, press the "gas flap" button on the dash a couple of times. On mine - that will extend the plastic pin & all is well.
Sorry I'm using such technical language as "gas flap"

 

Yep, keep that white plastic latch pin coated in lithium grease at all times. If you don't, your plastic pin will eventually weaken and break. Our 2005 S-Type went through multiple latch assembly breakages and replacements under the factory warranty before I learned in mid-2009 that I needed to keep it lubed at all times. I've done so ever since, and it has thankfully functioned normally as long as it stays coated in lithium grease. I wipe off as much of the old grease as I can without compromising the moving parts and give it a fresh spray at least every couple of months....