1999 E320 filler cap won't remove when turned...jams stuck to the fuel filler neck while stopped to fill-up. Fortunately, I had enough gas to get home. If you use a pair of pliers, you can work the cap back and forth till it releases. There is an inner plastic insert that when removed, allows the gas cap to "mostly" work. A new gas cap, I tried this already, will stick on the fuel filler neck same as the old one so it is NOT the gas cap that is defective.

I'm told that the metal fuel filler neck gets distorted and has top be replaced. WHAT! Some say you can't get just the fuel filler neck, but need the entire gas tank. Are we serious? A car, an E320 Mercedes at that, made in 1999 and the gas cap system doesn't work? Replacing the fuel filler neck seems to be a start to the next failure and not a real fix, too. At only 130,000 miles the cap hasn't been on and off all that much.

I haven't gotten into this repair yet, it will have to wait till the rusted through Right front suspension coil spring cap is repaired. My quick fix is to clip and REMOVE the inner plastic piece under the bow-tie metal fingers. Use a thin screw driver and insert it under the plastic piece and TWIST the screw driver till the plastic part pops in two. Removing inner plastic piece this allows a good enough seal to keep the loose cap warning light from coming on....so far, and the cap won't stick on the fuel filler neck.

There seem to be too many needlessly designed-in problems on this car as nice as it generally is.