Fuel Tank Contamination and Importance of Cleaning Fuel Tank

The fuel tank in your vehicle is an important part. You cannot afford to ignore its contamination. In this article, we will know what causes fuel tank contamination, effects of contamination, and how to maintain it for optimal functionality.

The fuel tank in your vehicle is an important part. You cannot afford to ignore its contamination. In this article, we will know what causes fuel tank contamination, effects of contamination, and how to maintain it for optimal functionality.

Causes of fuel tank contamination

  • Corrosion: It is said corrosion occurs because of improper maintenance of the tank, usage of fuel soaps and micro-organisms such as bacteria. The microbes are said to be principal causative agents of corrosion. These microbes stay in the moisture that is present in the tank. As they grow, they create waste, which causes corrosion in the tank because of their acidic nature.


The corrosion generally occurs at the bottom of the fuel tank. This is because the moisture collected is heavier and moves to the bottom, especially if the fuel contains high proportion of Sulphur. The moisture may come while handling transporting fuel, ground surface water contact and via damage to the tank or hoses. The moisture causes rusting in the tank and ultimately corrosion.

  • Dirt and debris: The dirt and debris in the atmosphere enter the fuel tank due to different reasons like loose or wrong fuel cap, damaged vent tube, usage of generic fuel filters that can erode easily, etc. The accumulated dirt and debris can clog different parts of fuel delivery system like the fuel lines, fuel filters, fuel injectors, fuel pump, etc. and thus impair the optimal function of the engine.
  • Contaminated fuel: One more factor that can cause fuel tank contamination is contaminated fuel. The fuel that is already contaminated can enter the vehicle's fuel tank from service station's fuel tank. As the tubes of the service station tanks are located towards the bottom of the tank, all the heavier particles settled at the bottom of the tank may mix up with the fuel and contaminate it. Especially, when the fuel level in the tank is low, the chances of contamination are high. Though the service stations use filters, they fail occasionally, allowing the contaminated fuel to enter the vehicle.


Effects of fuel tank contamination
A common misconception among people is that fuel pump strainers/filters will prevent the contaminants from entering the engine. But, in fact, those strainers may not be of much help because they cannot filter particles less than 35 microns. However, fuel injector filters that are next to the fuel pump in the fuel system can filter particles as small as 10 microns. Thus, it is obvious that any contamination can cause premature fuel pump failure. Fuel pump failure eventually affects the normal functioning of the engine.

Cleaning fuel tank prevents adverse effects of fuel tank contamination
Contaminants not only clog different parts of the fuel delivery system, but also cause rapid wear to the filters/strainers. Wearing allows small particles to enter the fuel pump and other parts accelerating internal wear, which in turn leads to suboptimal efficiency or complete failure of the engine. To prevent such eventuality, clean the fuel tank periodically.

Precautions to take while cleaning fuel tank
Cleaning the fuel tank is important as it helps you not only improve the performance of the vehicle but also boosts the longevity of the engine. You should, however, take certain precautions while cleaning it. Here are some:

  • Isolate the fuel tank from the vehicle as per manufacturer's manual.
  • Remove the fuel into a container as advised in the manual. Or, dispose it off at an environmentally safe place.
  • Don't use gasoline for cleaning the fuel tank. It may not completely clean water soluble contaminants, if any
  • . Fill the tank with a cleaning solution as per manufacturer's guidelines. Leave it thus for, say five to seven hours. During this time, the solution will dissolve solid matter like grime, dirt, etc. stuck to the inside walls of the tank.
  • Rinse the tank four-five minutes thoroughly. Rinse until the water used runs clear. Clean the outside as well.
  • Let the tank dry for at least 72 hours. Ensure the inside is completely dry before you install it.


Fuel tank contamination issues are common as it is not completely within your control to rule them out. However, cleaning the tank following the guidelines discussed is extremely important. It will make your vehicle less troublesome and you can make sure that the vehicle has optimal functionality for a few more years to come.

Airtex Fuel Delivery Systems is the leading aftermarket supplier of mechanical and electric fuel pumps and modular reservoir assemblies (MRA). For over 50 years, the Airtex brand has been the benchmark of fuel delivery and cooling system components for leading companies in the automotive aftermarket. If you are searching either for electric fuel pump or mechanical fuel pump, visit our site.

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