What happens if the knock sensor is broken?

[AngelaDella]

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.

[NolanRose]

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.

[KendraLee]

When the knock sensor fails, the engine will experience knocking, simply put, the gasoline in the cylinder burns abnormally, producing a rattling noise. The ECU control unit cannot receive the correct signal, making it unable to adjust the ignition timing, leading to a significant drop in combustion efficiency. This directly affects power output, resulting in sluggish acceleration, and a fuel consumption increase of 10-20% is not uncommon. Worse, if ignored for a long time, it may damage the cylinder walls or pistons, eventually leading to an engine overhaul costing thousands of dollars. I recommend listening carefully to the engine sound when driving and stopping to check immediately if there are any abnormal noises. Additionally, this issue is prone to false fault codes; when the check engine light comes on, don't rush to clear the codes. Instead, check if the sensor connector is loose or corrored. The replacement cost is not high, usually just a few hundred dollars.

[LeKayden]

A faulty knock sensor can cause the engine to lose its protection mechanism. When knocking occurs, the ECU cannot intervene automatically, leading to reduced power and increased fuel consumption in mild cases, or severe wear of internal engine components in severe cases. Common symptoms include hearing metallic knocking sounds during acceleration and noticeable engine vibrations, which can gradually damage pistons or valves. If not repaired promptly, consequences may include continuous power loss or even engine failure, with repair costs ranging from a few hundred to several thousand yuan. It's a good habit to check the dashboard lights before each drive and seek immediate inspection if any abnormalities are detected—prevention is key.

[Lena]

I've seen many cases where a faulty knock sensor makes the car drive like an old ox pulling a cart - sluggish acceleration accompanied by strange noises. With the ECU unable to properly adjust ignition timing, the engine runs in poor condition long-term, inevitably causing fuel consumption to skyrocket by an average of 15%. Over time, this may damage pistons or connecting rods, doubling repair costs. I recommend owners regularly monitor driving performance. If abnormal sounds are heard or engine instability is detected, seek professional diagnosis immediately at an auto shop. Replacing the sensor is relatively simple, costing just a few hundred yuan for regular cars, but don't delay to avoid engine damage.