Noisy operation of the fuel pump may signify a number of other root causes that may eventually affect the overall performance of the vehicle. The noise usually suggests that the fuel pump is working harder than it is supposed to, probably because the fuel filter is clogged, there is not enough fuel, or even wear and tear inside the pump itself. Quick diagnosis of a noisy fuel pump is important to prevent further damage and maintain the best performance of the vehicle. Normally, a good fuel pump should hum quietly, while louder or more consistent noise may indicate a problem.
One of the first things to check when diagnosing a noisy fuel pump is the fuel level. A fuel pump will have to struggle much harder to pull fuel when the tank is low, making more noise in the process. The Automotive Service Association studied it and found that over 40% of fuel pump noises were due to low fuel levels. Refilling the tank when it is almost empty may resolve the problem because the pump will no longer strain due to insufficient fuel supply.
If the noise persists after refueling, the next thing to check would be the fuel filter. A clogged fuel filter increases resistance in the fuel line, forcing the fuel pump to work harder and causing it to make noise. If the filter is clogged, it should be replaced, considering that poor maintenance can shorten the life of the fuel pump by up to 30%. On the other hand, in an industry report provided by the National Automotive Service Task Force, or NASTF, fuel filter problems have accounted for about 20% of all fuel pump failures.
Another possible reason your fuel pump might be so loud could be air within the fuel system. Air in the fuel line can make the pump run less efficiently, which produces louder-than-normal noises. Normally, this is due to a leak or crack in a fuel line. In a survey conducted by the International Automotive Technicians Network in 2020, 15% of noise issues with fuel pumps were due to air intake into the system. In this regard, it will be important to check the fuel lines for visible cracks or leaks that could determine whether this is the cause.
If it still cannot be traced back to either fuel level or a clogged filter, it may be necessary to check the fuel pump’s wiring and connections. Poor electrical connections can cause voltage irregularities that force the pump to work harder, generating noise. A faulty relay or fuse can also be a contributor. According to data from the Society of Automotive Engineers (SAE), electrical issues account for 10% of noisy fuel pump complaints. Using a multimeter to measure voltage at the fuel pump terminals can help pinpoint if the issue lies in the electrical system.
If all the above fail to eliminate the noise, the fuel pump itself could be on its way out. This can be caused by the mechanical wear and tear that happens inside the pump and makes it malfunction and start producing abnormal sounds. The average lifespan for fuel pumps ranges from 100,000 to 150,000 miles, though this may change in events of excessive stress and poor maintenance. According to the study done by the Car Care Council, some 12% of all car breakdowns are due to flawed fuel pumps. In such instances, replacement may be the sole option to return the vehicle to normal operation. Replacement costs do vary in different models: from $300 to $800.
Noisy fuel pump diagnosis requires careful attention to the fuel system and its components. Checking the fuel level, inspection of the fuel filter, and the integrity of the fuel lines and electrical connections may pinpoint the source of the noise and corrective action taken. If the noise is still persistent after these steps, the fuel pump may need to be replaced. For more information on fuel pumps, visit Fuel Pump.