What happens if the knock sensor is broken?
2 Answers
If the knock sensor is damaged, the engine control unit (ECU) cannot monitor the degree of knocking, leading to a false judgment that no knocking has occurred. The specific details are as follows: 1. In this case, the engine control unit will increase the ignition advance angle, causing the engine to operate roughly and shake due to knocking, resulting in detonation, or even engine seizure. 2. When engineers calibrate the knock sensor, they write the vibration pattern of knocking into the ECU. Once the knock sensor detects this vibration pattern, the ECU determines that the engine is knocking and immediately delays the ignition advance angle to suppress the occurrence of knocking.
When my knock sensor failed while driving, the whole car felt extremely uncomfortable. The engine started making a pinging sound, like metal knocking, and acceleration felt sluggish with delayed throttle response. Fuel consumption also increased noticeably - normally a full tank could last 500 km, but now it only reached about 450 km. The most annoying part was the constant slight engine vibration that could be felt throughout the car, making me nervous after prolonged exposure. After checking some materials, I learned this component detects abnormal combustion. If it fails, it can't protect the engine properly, potentially causing internal wear like piston damage or valve issues. My suggestion is to get it checked at a repair shop immediately when such symptoms appear - don't push through. Delaying repairs will make the costs skyrocket. During regular maintenance, pay attention to dashboard warning lights - when they illuminate, take prompt action to avoid bigger troubles and expenses.
