What is the reason for the loud noise from a newly replaced fuel pump?
2 Answers
The reasons for the loud noise from a newly replaced fuel pump are: 1. The viscosity of the hydraulic oil is too high; 2. Improper installation of the pump and motor, resulting in misalignment of the pump shaft and motor shaft; 3. Blockage in the suction pipe increases the resistance of the pump to draw oil, causing the pump to cavitate or air leakage in the inlet pipe section; 4. Air is trapped inside the pump. Solutions for the loud noise from a newly replaced fuel pump: 1. Select hydraulic oil with appropriate viscosity; 2. Adjust the alignment of the pump and motor installation; 3. Add oil into the pump to lubricate the pump's bearings, plungers, and cylinder block, and open the pump's oil filler port during operation to allow air inside the pump to escape from the filler port.
I often help friends with car repairs, and the most common issue with noisy new fuel pumps is improper installation. For example, if the fuel pump screws aren't tightened properly or the vibration dampers aren't positioned correctly during installation, the vibrations during operation can be particularly loud. Secondly, the fuel pump model might not match the car; if you bought a cheap or non-OEM part, the harder materials naturally produce more noise. Additionally, there might be air trapped in the fuel tank, and the sound of bubbles bursting during fuel suction can be quite loud. Poor-quality fuel with a lot of debris can also make the fuel pump work harder, causing a buzzing noise. Voltage issues can also trigger noise, such as an unstable alternator or aging wiring. I recommend checking it immediately—don't underestimate the noise, as it can wear out other components like the fuel filter and, over time, increase fuel consumption. It's annoying to hear while driving and poses a significant safety risk, so take it back to the shop right away for the mechanic to adjust, secure, or replace the parts.
