Fuel Contamination

Diesel Fuel System Contamination:

Warning:
Never drain or store diesel fuel in an open container due to the possibility of personal injury from fire or explosion.

Fungi and other micro-organisms can survive and multiply in diesel fuel if water is present. The fungi can be present in any part of the fuel handling system. These fungi grow into long strings and will form into large globules. The growths appear slimy and are usually black, green or brown. The fungi may grow anywhere in the fuel but are most plentiful where diesel fuel and water meet. As the fuel is agitated (when service station tanks are being filled), fungi are distributed through the tank and may be pumped into a vehicle.

Fungi use the fuel as their main energy supply and need only trace amounts of water and minerals. As they grow and multiply, they change fuel into water, sludge, acids, and products of metabolism. The most common symptom is fuel filter plugging: however, various metal components (fuel tanks, lines and injection pump) can corrode.

Warning:
To avoid personal injury, do not come into physical contact with biocides. If fungi have caused fuel system problems, use a diesel fuel biocide to sterilize the fuel system. Do not exceed the dosage recommended on the label. Discontinue the use of a biocide when towing a trailer. It is permissible to have biocide in the fuel when starting to tow, but do not add any biocide while towing. Steam cleaning may be necessary if most of the fungus growth cannot be removed with biocides.