Symptoms of a bad Knock Sensor

When the air-fuel mixture self-ignites too quickly, “knocking” happens. The cylinder head gasket and cylinder head are most hurt by persistent knocking. The knock sensor sends a signal to the ECU after detecting the high-frequency engine vibrations that are characteristic of knocking. By starting ignition as soon as feasible, the objective is to produce the most energy possible. Engines using knock sensors can use less fuel and generate more torque.

Well, in this article, we’ll be talking about the symptoms of a bad knock sensor. Let’s get started


What is the symptoms of a bad knock sensor?

Symptoms of a bad Knock Sensor

Check Engine Light

The engine light will come on, and an associated diagnostic problem code (DTC) will be set off when the Powertrain Control Module (PCM) discovers a bad knock sensor or voltage circuit.

Engine making Noises

The PCM might not be able to detect or adjust the spark knock frequency if the knock sensor fails. The engine may make a metallic pinging noise if the sensor fails. Additionally, you’ll observe that the noise is most noticeable while the engine is working under a heavy load.

Bad Engine Performance

Engine performance may suffer as a result of the PCM incorrectly changing the ignition timing brought on by a damaged engine knock sensor. When traveling at a high rate of speed or when the car is pulling a heavy load, the engine might not feel correct. Even if the check engine light is not on, you should get it checked by a professional in such a situation.

Poor Acceleration

When traveling on the highway, a faulty knock sensor may prevent the engine from starting effectively, resulting in reduced fuel economy.

Power Loss

Your car will probably lose power after the engine control unit notices the knock sensor isn’t operating properly. The engine’s maximum octane rating and how heavily it relies on knock sensor input will determine how much power is lost.

High-compression and flex-fuel engines are the ones that lose the most power in automobiles. That’s because the power loss delays the engine timing and keeps the transmission out of drive until the knock sensor is fixed.

Related Article


It is important for maintaining the health and functionality of an automobile’s engine to comprehend and recognize the symptoms linked to a defective knock sensor. Reduced engine power, poor fuel economy, or weird engine noises are just a few of the visible symptoms that might appear when the knock sensor starts to malfunction. It is crucial to address these symptoms as soon as possible because ignoring them can result in more serious engine issues.

Engine knocking may be averted, performance can be increased, and the engine can be kept safe if the knock sensor is working properly. Consequently, paying close attention to these warning signs and acting promptly is a crucial part of proper vehicle maintenance, assuring both engine effectiveness and long-term reliability.

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