Dripping Diesel
 

I came outside this morning and noticed a puddle underneath the back of my car (W126). I stuck my finger in it and smelled it and lo-and-behold it was diesel fuel. I looked under the back of my car and saw a small little bung or hole (looks like a drain of some sort) dripping onto the ground. I didn't jack my car up yet or anything to get a better look at it but it may be coming from in front of the tank too. Like I said, I can't tell yet but it looks to be coming out of that drain. It doesn't do it while the car is running. I'm at a loss. Any suggestions?

check and see if you put the fuel cap on properly.. I didn't one week and I got diesel everywhere and it dripped from out of the trunk as well

Im almost 100% sure I have. Why would it leak if the fuel cap is loose? I mean, shouldn't the fuel system be sealed anyway and not depend on pressure generated by a gas cap to not leak?

I've also noticed a significant decrease in gas mileage, and not just from this tank but the last few. Its gotten alot worse with this one but I think I have a couple broken teeth on my gears for the odometer/trip meter.

not from the fuel system but the sloshing around of fuel.

Did you know that all non metal fuel lines are supposed to be replaced with new lines ever 2-3 years? How much do you want to bet you are on the OG lines?