I have a 1999 C280. The gas inlet to the fuel tank has always been "sensitive" to nozzle angle etc but I never had problem filling my car. Recently something happened and I cannot put gas in my car. The gas nozzle kicks off almost immediately after starting the fill and when I pull the nozzle out gas pours out of the car on to the ground. I am talking a lot of gas, maybe 200 ml. I can see it in the end of the spout and it doesn;t real drain. It is not the service station's equipment becuase it happens at several stations. Is there some new method of putting gas down a pipe into a tank that MB complicated somehow? If I add gas VERY slowly it will go in. This happens no matter what the tank level. It is not teh gauge, it works fine.

 

Try turning the nozzel to the left (look at picture) and push it in slightly not too hard you might have to hold it in that angle. this might be your problem b/c it has happend to once before.

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no I know what you are talking about. THis is different. When the nozzle kicks off there is quite a bit of gas that comes back up the pipe. I have had this car since I bought it new so I know this is a new problem. Thanks anyway.,

 

generally, the gas goes down a rubber hose inside a metal tube. The rubber hose has a problem. This is usually an act of vandalism. Pull out the filler neck and see what you can see.

 

Checked the rubber hose. Its fine. I think its more complicated. I have heard something like a shutoff valve or maybe a pressure relief valve. Not sure. I am able to run a piece of 1/2" rubber hose down pretty far into the tank. I does behave liek a restriction but after the rubber section you described the piping to the tank is hard plastic and pretty large diameter.

 

Maybe worth checking to see if the breather that goes from the filler neck to a Charcoal condenser is not snagged/blocked, I think it is shutting of because of the amount of back pressure caused by the fill.

Another possability is somebody may have been stealing fuel from your car by disconnecting one of the pipes to drain off what they want, then when reconnected - twisted, or maybe even somebody tried sucking gas up from the actual filler, I know GM cars have an anti-suck valve to prevent this.

Just and Thought, and Good Luck!

2001 C320 Elegance - Brillaint Silver - Black Leather - Limited MB Wheels

 

you need to replace your upper gas tank filler neckassembly

 

why do you say I need to replace the upper assembly? The section that I put the gas in is metal. THen it connects to a rubber hose which then connects to a large hard plastic pipe that goes to the tank. What is in the upper assembly that can fail? Is it not just a section of pipe? I think a smaller vent tube connects to it. I know this all started after I went to a gas station whose nozzle failed to shutoff and the car overfilled. But I do not understand what could have been damaged. Unless it failed at the same time.
Nobody is trying to steal gas. I am surprised this has been mentioned in so many replies.
This happens whether the tank is full or empty. Can anybody tell me if there is anything like a check valve or something between the neck assembly and the tank?

 

It seems as if the "rubber bag" which lies inside the metal/plastic gas tank has loosened inside. You'll have to drop the tank, drain it the reset the bag inside the tank. Maybe the adhesive failed due to a leak in the rubber bag. Then again I may be wrong!!!!!!

 

Is there really a rubber bag in the tank? I have never heard of this. My car , since new, always had a very subtle issue filling the tank. But Since 1999 I could always turn the nozzle to allow full delivery. Are you sure MB has gone to a bladder system?