Fuel Contamination. 

What is Fuel Contamination ? 

The presence of either 
Foreign particulate matter 
Biological growth (diesel bug) 
in your fuel can be classed as fuel contamination. 
That said there is always a small water content in fuel from the manufacturing process. 

Do I have fuel contamination ? 

The simple answer to that is yes. All tanks have some contamination even a brand new tank. This may be a very small amount of foreign matter caused during manufacture or during fuel delivery. 
What is important is the level of contamination. 

Help. I have contamination. What Next ? 

If you have contamination then you must deal with it to prevent further breakdowns and possible engine damage. 
Depending on the contamination level there are 3 ways to deal with it. 
Tank cleaning or Fuel polishing 
Using a specialised fuel additive to kill the bug and deal with contamination 
Fitting of a suitable fuel conditioning filter 
If its just water contamination then fuel polishing alone should deal with the problem. 
If its foreign particulate or biological growth then the tank needs to be cleaned and possibly the fuel discarded. 
Having carried out tank cleaning and fuel polishing with our machines for a number of years now, we have found that the limited access to most fuel tanks does not allow a thorough enough job to be completed. Therefore we have stopped fuel tank cleaning and have found that the most reliable method is to remove the fuel and cut one or more access holes into the tank and physically wash and clean it out, this is a guaranteed 100% way of eliminating the contamination. We can carry out this service at our yard in Braunston. 

Should I be worried ? 

Looking after your fuel and storage tank should always be part of your maintenance regime. 
You should be worried if your fuel filters have major signs of contamination as in the pictures below. 
By then its too late and contamination has occurred and must be dealt with to prevent breakdowns and possible engine damage. 
Having seen first hand the damage to engine fuel systems and expense to the customer then good "housekeeping" of your fuel is a must. 

What can I do ? 

The first step is "good housekeeping" 
Ways of achieving this include: 
Where possible purchase fuel from reliable sources, 
Ensure your fuel tanks are regularly maintained and leak-free, 
Keep fuel tanks as full as possible to prevent water from condensing due to humidity, 
Consider the use of a fuel additive to prevent fuel oxidation and a fuel biocide to minimize microbial growth, 
Ensure you turn over your fuel regularly, some bio based fuels can start to degrade after 6 months, 
Fit an appropriate fuel conditioning filter in to the engine fuel supply system. An example of such a device is the FUEL PURIFINER or the FUEL GUARD filter. These can be fitted in to the fuel supply line to the engine or as an additional fuel cleaning system on your tank.