Hello

I have a strong gas odor in the trunk and also in the interior of my 1987 300E.

The gas smell seems to occur after I fill the tank. And then after driving for a day or two it drops off and then goes away until I fill it again.

Today working in the trunk I removed the back cover that covers the gas tank. I inspected the fuel gauge sending arear thinking I might have a bad rubber gasket there.

I then removed the plastic side panel / wheel well cover and could see gas stain marks under where the filler neck.

I went and filled the tank. At the pump I set the little catch to hold the pump trigger. When it was full, the catch released itself automaticly and the pump stopped pumping gas. I then pulled the pump lever and continued to add more fuel, after a few seconds the pump stopped and I put the gas cap on and drove off. Note: I think this might be the problem, I top it off after the pump already stopped, overfilling the gas tank

I drove about two miles and then pulled over with the car running, I went and looked in the trunk and didn't see anything. I then removed the gas cap (the car is still running) and lots of gas gushed out (I would guess 4-6 oz). I tightened it and then released it again and again gas gushed out. The gas came out and filled up the gas cap compartment at a rate faster then it could drain through the water drain hole. A small amount of gas was seeping on the outside of the filler neck into the trunk Inner wheel well area (through the black rubber gasket that surrounds the tanks filler neck).

After about three times of removing the cap and having gas gush out and replacing the cap, on the next try no gas gushed out. I guess I got teh excess gas out.

So am I causing this problem by overfilling the tank? Or do I have excessive pressure in my tank?

The water draing in the gas cap compartment does work as I got a bottle of water and poured it and saw it come out the bottom onto the street.