Knock Sensor Function

Engine knocking is one of the most hazardous attribute of a vehicle, which results in loss of power and causes severe damage to the engine. It occurs as a result of ignition of fuel and air within the cylinder before the actual moment it was supposed to occur. Basically, knock sensor function is to identify the problem of knocking and alert the driver about the same.

Why Use Knock Sensor?

According to the experts, operating a vehicle near the detonation (ignition of fuel and air with the help of a spark from spark plug) limit helps in producing more power and adds to the performance of the vehicle. That being said, there is a thin line of difference between operating a vehicle near the detonation limits and beyond it. As we mentioned earlier, operating a vehicle with knocking engine can result in some serious damage to the engine, and therefore one has to monitor the engine for knocking while driving, and this is where a knock sensor comes into picture. Simply put, a knock sensor helps you monitor engine knocking and ensures that the various engine problems associated with it are kept at the bay.

Functions of the Knock Sensor

A knock sensor is a low voltage producing device which detects harmful engine vibrations in the vehicle, and alerts the on board computer to take the required action. This in turn helps you drive the vehicle at peak of advanced engine timing, without being afraid of causing any damage to the engine owing to excessive knocking. This sensor generate electrical charge when it detects abnormal vibrations in the engine of the vehicle. It is specially designed to record the faint vibrations with the sound of engine in the backdrop. When excessive knocking is recorded, the sensor sends electric signals to the on board computer of the vehicle, which in turn reduces the speed of the engine automatically.

As the engine speed is lowered, the rate at which the spark plug fires is lowered and the knocking of engine is eliminated. The computer continues to keep a track of the signals sent by knock sensor throughout the process, and brings the speed of the engine back to normal once the knocking is completely eliminated.

The placement of a knock sensor plays a crucial role in its functioning. Ideally, a knock sensor has to be placed in between the cylinders, as this will ensure that misfiring in either of the cylinders will be recorded promptly. In several cars with advanced engines, more than one knock sensors is used, which makes the task of detecting engine knocking even easier.

Like various other components of the vehicle, even knock sensors are prone to excessive wear and tear, which can render them useless after a specific period. In such circumstances, you may have to replace it to ensure smooth functioning of the engine. In a vehicle with worn out sensor, you may observe abnormally high knocking, the sound of which will be louder than the sound of engine itself. On an average, a knock sensor will cost you in the range of $20-$100, while the replacement cost will depend on a range of factors including the model and where you go to fix the problem.

At the end of the day, even though it may seem to be a bit costly, it can save you a significant amount of your money which you would have to spend on a damaged engine, and hence a knock sensor is a must for your vehicle.