Do you want to risk a spark, or heat from the drill, setting off a gas fire?

I had the same problem happen with my '89 300TE. I managed to pry the gas cap off by inserting a screw driver between the edge of the cap and the edge of the filler neck. The I "jiggled" the screwdriver as I turned the cap in an effort to "pop" the cap off. If you are able to align the "hooks" in the bottom of the cap with the "openings" on the filler neck while using the screwdriver as a lever you will be able to pry or pop the cap off.

In my case it was an old and broken gas cap that caused the problem. The bottom of the cap has a plastic part, that turns (as you close the gas cap) and locks the cap in place. This part gets old and worn and then when it locks it won't disengage from the filler neck.

The filler neck is made out of a soft metal (aluminum?) so be careful not to distort it. If you damage the filler neck, you will have to replace the entire tank because the filler neck is an integral part of the tank.

Good luck.

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Current Benzes

1989 300TE "Alice"
1990 300CE "Sam Spade"
1991 300CE "Beowulf" RIP (06.1991 - 10.10.2007)
1998 E320 "Orson"
2002 C320 Wagon "Molly Fox"

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