If a car's gas tank is vandalized by someone adding water, salt or sugar to it, the engine may sputter, hesitate, knock or lose power. Water may also cause the exhaust to be tinged white. If the vehicle's fuel lines or gas tank show signs of premature rust, or if you detect a chlorine smell around the car, vandals may have added bleach to the fuel tank.
If water is present in a gas tank, add Drygas, or a similar product containing anhydrous methanol or azeotropic isopropyl alcohol, to the fuel. These additives absorb the water and bind it in solution. The solution has a lower freezing point than water to prevent fuel line icing, and it can be burned by the engine, removing the water. Alternatively, a mechanic may drain or siphon the gas tank to completely remove the contaminated gasoline.
If someone has added sugar or salt to a gas tank, the contaminant is typically suspended in the fuel and becomes distributed throughout the entire the fuel system. The solution may clog fuel filters and injectors. A professional mechanic must disassemble the entire fuel system and either clean, repair or replace all the components.
To fix a fuel system contaminated with bleach, drain or siphon the tank before running the vehicle, if possible. If the vehicle has been run with the bleach mixture, the entire fuel system may need to be replaced.