In warm or humid weather, fungi and/or bacteria may form in diesel fuel if there is water in the fuel. Fungi or bacteria can cause fuel system damage by plugging the fuel lines, fuel filters or injection nozzles. They can also cause fuel system corrosion.
If fungi or bacteria have caused your fuel system problems, have your authorized dealer correct these problems. Then, use a diesel fuel biocide to sterilize the fuel system (follow the biocide manufacturer’s instructions). Biocides are available from your dealer, service stations, parts stores and other such places. See your authorized dealer for advice on using biocides in your area, and for recommendations on which biocides to use.