Both studies and examples from the field suggest contamination of fuel is a frequent cause of fuel pump failures. Fuel contamination usually consists of water, dirt, or rust bits that clog the pump. Conventional wisdom attempts to counter the costs of a fuel pump with a 100,000-mile service life — but a contaminated fuel system can slash that lifespan in half and lead to failures much sooner.
How the mechanic of this failure works starts with some debris clogging the fuel filter or pump itself. Smaller particles, even those that measure 10 microns or less can clog and jam the internal components of a pump, damaging them by causing excess heat and lowering flow rates. Automotive engineers often cite this as “abrasive wear”, where contaminants in the oil erode the pump’s internal gears and motor components and ultimately lead to mechanical failure.
One example of this is the recall of more than 200,000 Subaru vehicles in 2020 due to premature pump failure caused by contaminated fuel. Complaints included stalling and trouble while starting the engine, and upon investigation, it turned out to be caused by fine rust particles in the fuel system damaging the pumps. Subaru recommended both replacement of the fuel pump and the fuel filter, at a cost of more than $500 per vehicle.
Corrosion is also worsened by fuel contaminants. Metal components of the fuel system interact with water to form rust that clogs pump passages. According to a study conducted by the Society of Automotive Engineers (SAE), 0.1% water in fuel reduced pump efficiency (30%,) thereby severely degrading engine performance. This underscores the importance of storing fuels correctly — and installing quality filters to mitigate contamination.
Cleanness of the fuel systems “is where we come in: Quality fuel protects your engine, but no good oil stays clean on its own without proper maintenance,” Shell CEO Ben van Beurden said in a statement. Changing fuel filters every 30,000 miles is an example of preventative maintenance that minimizes the threats from impurities and enhances pump longevity.
Impaired samples frequently show particulate contamination levels that are far beyond the permissible limit of 24 mg/kg as per industry specifications. If contamination is found, having the pump replaced and/or the tank cleaned will run you anywhere between $400 to $1,000 depending on the vehicle make/model and shop labor rates.
For reliable performance, proactive contamination management and heavy-duty replacement parts are most important. Find the best solutions with Fuel Pump.