Diesel “bugs” are not creepy-crawlies, but usually a fungus that can be a serious problem. At worst diesel “bugs” can literally stop your engine, just when you need it most .. like in an emergency! How can a “bug” do this? By blocking the diesel fuel supply line to the engine, usually at the fuel filter.
SUMMARY:
All diesel fuels contain micro-organisms (commonly called “bugs”) and when the conditions are favourable the “bugs” will rapidly grow. Both “bugs” and asphaltenes (aged diesel sludges) can cause fuel filters to block, with subsequent engine malfunction, or worse still, engine stoppage. Removing water from fuel tanks and keeping the fuel fresh goes a long way to controlling the problem. Other steps that can be taken to control “bug” growth are using a good quality diesel additive such as FTC catalytic decarbonizer, or a specific biocide and a proven magnetic unit.
Long storage of diesel fuel increases the potential of “bugs” to grow and asphaltenes to form.
DIESEL FUEL “BUGS”:
Diesel fuel “bugs” can cause fuel filters to block, with subsequent engine malfunction, or worse still, engine stoppage.
Diesel fuel “bugs” are actually micro-organisms comprised of fungi, yeasts and bacteria which live mostly in the diesel / water interface inside the diesel tank. The common diesel ‘bug’ is the fungus Hormoconis resinae that can produce a large biomass of mycelia (fungal matting) in a short period of time if the conditions are favourable. Hormoconis resinae is called “diesel bug” in the diesel fuel industry and “jet fuel fungus” in the aviation industry.
The mycelia of Hormoconis resinae excrete acids that can break down weaker tank material such as aluminium.
Water, nutrients and warmth are the pre-requisites for “bugs” to rapidly grow, blocking filters and damaging engine fuel components. Water commonly comes from condensation inside the fuel tank, but can also be either free water (fresh or salt) or emulsified water. Free water may have come from faulty bulk storage tanks, or from rain, or sea water entering through fuel tank filler caps with faulty seals. Nutrients can include the alkanes in the fuel, dead “bugs” and even the fuel tank material. Warmth is usually from the local ambient conditions, but diesel tanks in engine rooms and non-cooled high flow return lines into small fuel tanks will increase the diesel tank temperature.
Long storage of diesel fuel also increases the potential of “bugs” to grow.
OLD DIESEL SLUDGE:
Diesel “bugs” should not be confused with asphaltene chemical sludge compounds formed as diesel fuel ages. Asphaltene sludge can also cause fuel filters to block with subsequent engine malfunction, or worse still, engine stoppage.
Diesel fuel degrades with time (faster at higher ambient temperatures), often forming insoluble asphaltene compounds through an oxidation process. Prevention is the best cure. Use fresh diesel fuel where possible, which may mean keeping fuel tanks partially full if they are not used frequently. This can be a “Catch-22” situation, as condensation (water) is more of a problem in partly full tanks. Condensation promotes “bug” growth and rust to form.
Long storage of diesel fuel increases the potential of asphaltenes to form.
DIESEL BUG CONTROL:
“Bug” (microorganism) growth can be prevented by good fuel management procedures and specific fuel additives. Removing water that accumulates in your diesel tank is the best method of controlling “bug” growth. Do this by draining any accumulated free water weekly. Free water, including condensation, sinks to the lowest points in the fuel system, whilst the diesel “floats” on top. Fitting an in-line see-through water catchment bowl with incorporated drainage tap at a low point makes draining water relatively easy.
You may wish to check out FTC catalytic decarbonizer, which removes small amounts of “free” and emulsified water in the diesel and is also biocidal, thus inhibiting the development of “bugs”. FTC catalytic decarbonizer not only removes small amounts of water in diesel, it is one of the best products to remove choking carbon deposits within the engine .. including hard cylinder glaze. Specific biocides for controlling diesel “bug”, usually have no effect on carbon deposits.
Another method of controlling diesel “bug” growth is the use of a proven magnetic unit such as the ‘Bug Disrupter’. This unit has been proven by an independent laboratory, Condia Bioscience, UK, to inhibit fungi and bacteria growth and reverse the yeast colony count. This magnetic unit has no effect on carbon deposits.
There are some “bugs” in all diesel fuel, no matter how ‘clean’ it looks, therefore an additive such as FTC catalytic decarbonizer, or a specific biocide and a magnetic unit such as the ‘Bug Disrupter’ will be worthwhile ‘tools’ in your fuel management regime.
And yes, it can be a “Catch 22” situation, too much fuel may mean it gets “old” and asphaltenes form, too little fuel may mean a lot of condensation (water) for “bugs” to grow, but in our experience “bugs” which are quite common are easier to control than asphaltenes.
