There are a whole bunch of fuel lines back there associates with the expansion tank and the ventilation system for the fuel tank. You'll need to poke around and look for exactly which line is leaking, then see if it's an easily replaceable line. Until then - don't fill up to the top?

Similar thing happened this fall when I overfilled the M5 a bit. I got fuel into the 23 year old expansion tank lines, which started sweating and stinking. I took a nice long drive to burn some gas. The car is so great for that.....

 

Thank you. I circled where it leaks from. Hopefully this isn't going to be that expensive. It doesn't seem to matter how much gas I have in the tank it just leaks when I pump fuel in.

 

I believe that is where the overflow drain comes out (ie. if you pump too much gas in or it gets backed up for some reason, the extra gas will drain down a tube and come out where you circled - instead of overflowing the at the fuel door and draining down the side of the car.).

Unless you are overfilling each time, I do not know why that would happen.

Does it happen no matter how much you put in (ie. if you only put 2 gallons in, stop the pump allowing anything to drain into the tank, and then remove the nozzle)?

Or does it happen constantly while filling up?

 

Yes it leaks no matter how much gas it already has in the tank and it starts leaking as soon as I start pumping.

 

Sounds like there`s a chokepoint somewhere in the filler neck, which is diverting fuel back to the overflow valve. Can you try to snake it out with something like a length of garden hose ?

 

Sounds like Bob is right, but WTF could possibly be clogging that pipe? You didn't stuff a cloth in there when you lost your gas cap at one point did you?

Suggested temporary solution: If you pump a gallon of gas at full flow and 25% spills out on the groung because an obstruction won't allow that much gas to flow through the pipe, fill your tank up at 75% of full flow and see if that stops the spillage. Go to 50% of full flow next if 70% is too much. If this doesn't work at some level of reduced flow I'd suspect you actually have a hole in the filler pipe.

 

Could it be because the vapor recovery system of that certain gas station you are going to is not working correctly? One time it happened at a gas station, I went in and told the attendant. He said, "I know" and I was thinking to myself WTF? I should have reported them to the state commission for running a station knowing their vapor recovery system did not work. Ever since I got the E46, I noticed this...doesn't happen at every station and sometimes it depends on the angle you use on the nozzle. For the most part when it is full, the handle pops and stops. However, every time I pump gas though, I wonder if it is going to stop so I try to keep an eye on it. I have had this happen about 3 times. Sometimes though it pops way too early. So I adjust the way I have the nozzle and it continues then pops when it is full, but there are those times when it doesn't :dunno:

Overfilling like this whether accidental or on purpose (yes there are those that do it, me not being one of them that like to top off and continue once it has stopped) supposedly ruins the charcoal filter...item #22 in MicahO's picture.

 

Appreciate all of the helpful suggestions. The issue is a certain type of pump cover that does not allow the nozzle to enter all the way and it spills over into the vapor recovery system. (it's the short version) I received a Bentley Manual for Christmas so I was able to check around the fuel system. Now the money I saved for my possible repair is going to a second first aid box for under my driver's seat, Love those things :bigpimp: