How to get water out of a gas tank - 2002 BMW 5 Series

If it is allot of water you will need to pull the tank, if the water is muddy you will need to pull the tank. If it is just a little water you can pump it out by using the in tank electric fuel pump by jumping the fuel pump relay and powering up the pump all the time. If the water has been in the tank very long you may have much more serious problems with parts like injectors being ruined from water deposits and rust. In some cases you can absorb the water by adding a pint of denatured alcohol to the tank, it is available from any hardware store.

If you know water hasn't flooded into the tank and it is only a little bit (which still sinks to the bottom because water is heavier than oil or gas) you can add HEET available at almost any auto parts store. Add it to the gas. Water and oil don't mix but there is a special alcohol (and don't use rubbing alcohol, it is isopropyl, meaning it has already soaked up as much water that it can) in it that absorbs water and lets it combine with the gas so it can be burned.