What Does a Knock Sensor Do?

One of the car parts that you may have heard about is the car knock sensor. The car knock sensor is located on the intake manifold, engine block or sometimes the cylinder.

What Does a Knock Sensor Do?

The knock sensor is aptly named, as its job is to determine if the pulsations – or knocks – that are coming from engine detonation are abnormal or not.

It is basically a computer with its own ear that helps you determine if your engine is working properly.

Here are more details that may help you understand better how it knock sensor works, and especially how a faulty knock sensor reacts.

Problems With Your Knock Sensor

If you have a bad knock sensor, you will notice that the engine does not feel right when you’re driving.

This is especially discernible when you’re driving at high speeds or when you have something heavy loaded into your vehicle.

Even if your check engine light does not come on, if you feel like there is something off with your vehicle then you should definitely have your car checked out by a mechanic.

It may be a bad knock sensor or it may be a bigger problem that is not being identified because of a faulty knock sensor.

You also may not be able to accelerate properly when you’re driving on the highway.

A bad knock sensor will cause your car to get lower gas mileage. If you feel like you are not getting as much out of your gasoline is used to, or you are having trouble accelerating when you’re a high speeds, and you definitely want to have your knock sensor checked out.

Even if it is not a knock sensor problem, not being able to accelerate properly on the highway is a big problem that you should definitely get fixed.

The Roll Of The Computer

Your vehicles computer is able to discern different sounds coming from the vehicle’s engine. If there is a specific sound that the computer does not recognize and already have in its database, then the check engine light will go on.

This is the same way that a knock sensor works as well. If the knock sensor detects some sort of abnormal vibration, then your check engine light is going to go on.

That’s why it is so important to have your car checked out if your light goes on.

When the computer realizes that the sensor is not working properly, your vehicle is going to reduce power.

The amount of power that you lose will depend upon the octane limit of your car.

It also depends upon how much your engine relies on input from the knock sensor. High compression vehicles and flex fuel vehicles are going to be the ones that will lose the most power.

This happens because the loss of power slows the timing of the engine and keeps the transmission out of the drive function.

The slow timing is a safety feature that is designed to notify you that you need to get the vehicle fixed.

You will still be able to travel short distances, but you will not be able to go very far until you get your sensor fixed.

Replacing A Knock sensor

The knock sensor listens to the vibrations of the engine and will decrease your acceleration until you replace it.

When you have a faulty sensor, there is a good chance that higher emissions are going to come from the engine because the engine may run hotter than normal.

The EPA has rules against engines that are running now hot, and you will not be able to pass an emissions test from your state – if your state is one of the ones that require an emissions test.

What Does A Knock sensor Do – Conclusions

The bottom line is that if you think that your knock sensor might need to be replaced, then you definitely should get your car checked out by a certified mechanic and find out for sure.

Even if it is not the sensor that is the problem, you may have another problem that will cause you higher repair costs down the road.

The knock sensor is a vital component of your car and needs to be in working order in order for your vehicle to run properly.

You can run for a short time without it, we should get fixed as soon as possible.

So, next time someone asks “what does a knock sensor do?”, you should be able to answer.

Was that helpful?  let us know below.

Here is another informative article on knock sensors.

Why not check out our latest post on working out how much oil to put in your car here.

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