Fuel tank won't fill, gauge reading wrong
 

My '99 ML and '99 SL have recently developed the same problem. They will not take more than about a three/quarter fill (according to the gauges), and the fuel gauge readings are very erratic. The readings can change before/after a fresh start-up, going from half full to empty between starts. I have searched the forums and cannot find a solution. Anyone know what's wrong??:confused:

do a search for athread entitled "whats wrong with costco gas" or something like that. might be related.

Hey, looks like you're right. The investigation begins...

Try This!
 

I have had the same occurrence with each of my 1995 C280 and 2000 ML320. Some say you need to replace the fuel level sending unit but before you go to all the trouble and expense try changing gasoline brands. This is what I did and the issue went away after a couple of tanks of gas. More than likely you have bad gas (either high sulphur or other contamination). Keep us advised of what happens.