Indeed, fuel pump malfunction may cause knocking sounds in an engine. This may result whenever the fuel volume is not supplied appropriately by the fuel pump, thus causing a lean fuel mixture. In many instances, this leads to knocking of the engine, a situation where ignition of the air-fuel mixture takes place rather too early. According to studies, running on a lean mixture increases the possibility of knocking by 30%, which in turn adversely affects engine performance.
Combustion efficiency also depends on the pressure of the fuel pump. A fuel pump with lower designed pressures of about 30 to 60 psi might cause erratic fuel delivery. Pressure drops may result in inconsistent fuel spray from the injectors. For example, if the fuel pressure falls below 20 psi, the injector may not properly atomize fuel, thus causing misfires and knocking sounds.
The major vehicle manufacturers put great emphasis on fuel pump integrity maintenance. For instance, Ford mentions that a good working fuel pump is pertinent to good engine performance. In case the pumps fail, when an engine runs lean, drivers may notice knocking sounds, mainly when acceleration or under load conditions.
Besides that, fuel pump problems can be another beginning of a problem that will eventually clog the fuel system with contaminants. In an instance where a pump is clogged or failing, its inability to draw fuel from the tank will be very poor and may cause debris to be pulled into the engine. The overall effect of contaminants in the system causes a surge in the wearing out of the engine and engine knock. The American Automobile Association says that fuel system maintenance that is neglected can drop the efficiency of an engine by about 20%, promoting knocks.
It becomes relevant to note that knocking sounds can also be due to some other reasons such as improper ignition timing or carbon deposition. However, in cases where a lean condition is aided by the failure of a fuel pump, it could easily cause knocking sounds. So, fuel pump failures may be avoided by routine checks and maintenance. As says John McGowan, “Preventive maintenance is the watchword for avoiding high-cost repairs and smooth operation of the engine.”
Conclusion A faulty Fuel Pump would contribute to knocking noises due to the insufficient supply of fuel and resultant lean mixture. Operating the pump within specified parameters ensures that engine efficiency is well managed, hence at a minimum, any knocking.