How to Test a Knock Sensor

What You'll Need
Crescent wrench

Most vehicles nowadays are equipped with an automatic knock sensor. This is an important device that helps notify you that there is overheating in the engine and can help prevent engine detonation. It helps in regulating the air-fuel fusion in the vehicle’s engine. If you are unfamiliar with your vehicle’s knock sensor and you want to know if it’s working perfectly you can follow these simple steps.

Step 1 - Prep Work

Park your vehicle on an even surface, start your engine, set the emergency brake and open the hood.

Step 2 - Locate the Knock Sensor

Trace your knock sensor. This is commonly located underneath the intake manifold which is in the middle of the vehicle’s engine.

Step 3 - Checking

Simply smack the intake manifold using a crescent wrench and listen to the sound of your engine. If you can hear a slight change on the engine’s sound, then your knock sensor is working.

Step 4 - Another Way to Check

Another way of checking the knock sensor is by listening to and feeling your car’s engine while you are driving. There shouldn’t be a continual knocking sound and the engine should reach desired speed instantly. If not, you should bring your car to a mechanic for a simple diagnostic test.