If the fuel pump buzzes, it means it is running under stress; this can be from low fuel, a clogged fuel filter, or it has rubber; all are signs that the pump is showing excessive wear. In a normal state, a fuel pump operates silently, providing fuel at a consistent pressure, typically between 40-70 PSI for fuel-injected engines. The familiar buzz of the pump is often accompanied by a waning ability to hold this pressure, often due to insufficient cooling from the fuel surrounding it. Also, try to keep the tank at least quarter full — running around with a near empty tank reduces the need for the pump cooler with the dampened fuel and can increase wear by 30%.
If the fuel filter is clogged, the pump will buzz due to restricted flow causing it to work harder. As time goes by filters accumulate dirt and debris from the fuel which raises the resistance and pressure inside the pump. Having the fuel filter swapped out every 30,000 miles or so can eliminate this strain, resulting in a lower buzz and a longer life span as the pump is working without a lot of effort to draw the fuel in.
Buzzing can also result from electrical problems, including corroded electricity connections or voltage drops. These fuel pumps operate within a tight power band of 12-14 volts, and any drop in power makes them erratic, leading to buzzing noises. While mechanics say corrosion is generally a problem for wiring due to wear over time, they advised looking at all aspects of the wiring to see if corrosion was the cause for what they believe is the voltage in the pump.
As automotive expert Ed China once said, “If something goes clonk, then it means some part isn’t doing its job well.” A pump that constantly buzzes can then lead to more serious problems so catching those sounds early can save you from a breakdown which can cost you a lot of money to repair or replace.
A quality Fuel Pump capable of operating under many different conditions and designed from components which are robust, means less buzzing, and reliable, quiet operation over a broad range of fuel levels and driving conditions.