What Causes Knocking Sounds When the Fuel Injector is Faulty?
2 Answers
If it's a diesel electronic fuel injector, the issue could be excessive fuel injection in a single cylinder or premature fuel injection. It is recommended to calibrate the pre-injection quantity and mid-speed fuel quantity (emission point) for both old and new injectors. A significant deviation in idle fuel quantity can also cause knocking. More relevant information is as follows: Cleaning Method: Fuel injectors are generally cleaned every 2 years or 50,000 to 80,000 kilometers, depending on the quality of gasoline in the vehicle's usage area. The cleaning methods for fuel injectors include non-disassembly cleaning and disassembly cleaning. Precautions: Cleaning the engine fuel injector is essential, as the performance of the injector fundamentally affects the power output of each engine. Poor fuel quality can lead to injector malfunction, causing severe carbon buildup in the cylinder, accelerated wear of the cylinder liner and piston rings, unstable idle, increased fuel consumption, lack of acceleration power, difficulty starting, and excessive emissions. In severe cases, it can completely clog the injector and damage the engine.
A faulty fuel injector can indeed cause knocking sounds in the engine. I've encountered this situation many times during my car repair work. The root cause is that injector malfunction leads to unstable fuel supply – either insufficient fuel injection or improper injection timing. This results in uneven combustion of the air-fuel mixture in the cylinder, creating abnormal pressure fluctuations that produce those characteristic knocking sounds. These noises are usually similar to engine detonation. If not addressed promptly, it may accelerate engine wear or even damage pistons or cylinder walls. When facing this issue, I recommend first checking whether the fuel injector is clogged or leaking, then cleaning or replacing it if necessary. You should also inspect the fuel filter and fuel pump for related problems. For prevention, using high-quality fuel regularly can reduce carbon buildup and prevent premature injector failure. After all, the engine is the heart of your car – proper maintenance ensures long-term performance.
