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Have a fuelling problem on my E60 520d. I can't get any fuel into it at the garage, when I fill up the pump instantly shuts off (like when its fully filled), even though the tank is only half-full, I have to try and fill it really slow and can only get a few litres in before its starts overflowing and spilling out. Almost like the filler neck fills up with fuel, then very, very slowly drains out of the filler neck, into the fuel tank.

Thought it might be a fuel vent valve (but not same symptoms), or some kind of breather hose problem ? Not seen any guidance online about this problem ?