Generally, a noisy fuel pump indicates the beginning of failure or some damage to it. These noises usually occur due to wear and tear on the internal parts of the pump, such as the motor, bearings, or impellers. Normally, a fuel pump works very quietly; however, as time goes by or if it develops a problem, it may start making different types of noises, like whining, buzzing, or grinding. These noises are due to a number of reasons that include low fuel, a clogged filter, or an internal malfunction. When a fuel pump is operating normally, it works by pressurizing the fuel and sending it through the fuel lines to the engine at a pressure of 30 to 60 psi for gasoline engines. In newer units, such friction may be too minuscule to hear over standard sounds, but with older systems or those that have wear-and-tear inside, said friction causes whining and/or buzzing. A 2019 Ford study noted a whine could be evident and louder under acceleration conditions due to a fuel pump having worn-out bearings. Also, a clogged filter or failing relay making the fuel pump work harder to deliver fuel will make more noise as it struggles to keep up with the demand.
Low fuel levels can amplify fuel pump noise. With a nearly empty fuel tank, the pump has to struggle hard to draw fuel through the lines. According to a study by AAA in 2021, almost 25% of fuel pump failures were related to running the tanks low, since the pump depends on fuel to keep its components well lubricated. Without sufficient fuel inside the tank, the pump may overheat and further wear down, causing it to be noisier. This is quite a common problem with older cars, especially those with high mileage. Running the fuel pump on low for extended periods puts additional strain on the pump, which can cause permanent damage and make it noisier and less effective.
Another common cause for noise from the fuel pump is a clogged fuel filter. The work of the fuel filter is to block dirt and other particles from getting into the fuel system; however, over time, it may get clogged up with dirt and particles. This limits fuel flow, forcing the pump to work harder in order to deliver fuel to the engine. A 2018 Toyota report noted that a clogged filter may reduce flow rate by up to 40%, creating conditions for the fuel pump to become noisy in an effort to struggle through maintaining pressure. In this case, the noise could get louder as the vehicle is accelerating, requiring more fuel.
The origin of some noise may be purely electrical in nature. An inability for the proper voltage to be transmitted to the pump often rests with the fuel pump relay or fuse, which then keeps the pump running inefficiently or makes noise. Common in most Chevrolet models due to faulty wiring in the fuel system, the electrical elements of the pump may indeed cause a buzzing sound. A study done by Chevrolet in 2017 states that 30% of the cases involving noise from the fuel pump were due to electrical malfunction.
The other probable cause could be the age of the fuel pump. The average lifespan of a fuel pump is 100,000 miles. Beyond this mileage, there is a possibility of degradation of the internal parts that may lead to increased friction and noise. As a pump ages, the diaphragm, motor, and bearings can wear out, creating a whining or buzzing sound. In a study of high-mileage vehicles conducted by Honda in 2018, it was found that fuel pumps in cars over 120,000 miles were 50% more likely to make unusual noises, especially under load.
Poor quality of fuel may also be another reason for noise from a fuel pump. Fuel with a high content of water or sediment will eventually destroy the fuel pump, which will start making a grinding or gurgling noise. This mostly happens in areas where the quality of fuel is bad or where the vehicle has to go through very bad conditions. ExxonMobil found that poor fuel quality can decrease fuel pump efficiency by up to 20%, increasing the likelihood of noise and eventual failure.
If you hear unusual sounds coming from your fuel pump, it is essential to address the issue promptly. Ignoring the noise could lead to complete pump failure, which could leave you stranded or cause significant engine damage. The cost of replacing the fuel pump varies from $300 to $800, depending on your car’s make and model, with the replacement time estimated to take about 2 to 4 hours. A well-kept vehicle includes regular maintenance like replacing the fuel filter and cleaning the fuel system of possible debris that can cause noise in your fuel pump.
If you are concerned about fuel pump noise or need to replace your pump, you can visit Fuel Pump for more information and solutions.