The first step in testing a fuel pump for water contamination is understanding how water could affect the fuel system. Water in the fuel can cause considerable damage to the fuel pump and other components, such as the fuel injectors and fuel lines, by causing rust, corrosion, and improper fuel combustion. Water contamination can lead to a loss in the overall efficiency of the engine, with as high as 30% reduction in performance, according to studies in the industry. The two most common ways to detect water contamination are through the fuel filter and fuel sample tests.
The first step in checking for water contamination involves inspecting the fuel filter. Fuel filters are designed to catch contaminants, including water, before fuel reaches the engine. If water is in the fuel, it will often collect in the housing of the filter or be seen as a distinct layer, since water is denser than fuel and settles at the bottom of the filter. Most vehicle fuel filters should be replaced every 30,000 miles in, for example, a Ford F-150, to maintain good quality fuel. If the filter has visible water or sludge, it is showing the presence of water contamination within the fuel system.
Collection of a fuel sample would also be another method where a sample is taken from the fuel and visually examined for any signs of water. You can siphon some fuel using a clean container from the fuel line or the fuel tank. If it appears cloudy or contains droplets of water, that’s confirmation of contamination. Water contamination is responsible for up to 15% of fuel-related engine issues, according to a report by the Automotive Maintenance and Repair Association (AMRA). A water detection paste can also be used in conducting a fuel sample test; this usually changes color whenever it contacts water. This is especially useful for checking the fuel tank for the presence of water.
In some cases, a more advanced method for checking water contamination is the water-in-fuel sensor that is fitted as standard on many newer vehicles. Some sensors can even detect small-scale water quantities in the fuel and send signals to onboard diagnosis. As an example, the Mercedes-Benz E-Class gives the driver an alert when there is excessive water contamination than the usual limit to save the fuel pump and its fuel system from potential damage. The sensor works by monitoring changes in the electrical conductivity of the fuel since water is more conductive compared to fuel.
When there is any detection of water contamination, it becomes necessary to drain out the adulterated fuel and refill with appropriate clean fuel. In critical situations, the fuel pump has to be removed and checked internally for possible damage. Water can cause rust and corrosion inside the pump’s components, which may lead to a complete failure. According to a study by SAE, fuel pumps subjected to water-contaminated fuel can fail prematurely, with an average life reduction of 40-50% compared to pumps running on clean fuel. If this happens, replacement of the faulty fuel pump is the only way to make the engine work properly.
Water in fuel is a critical issue that may lead to poor performance of the engine, corrosion of important parts, and even failure of the engine. Detection will involve regular checks of the fuel filter, use of fuel sample tests, and looking out for the warning lights from water-in-fuel sensors. In this case, if the fuel pump shows any signs of damage due to water exposure, then it is advisable to replace it with a reliable Fuel Pump for continued optimal performance of the engine.