How to Replace the Knock Sensorby Thomas West
Automakers begin using computerized engine controls starting in the 1980s. Modern computerized engines utilize a spark knock sensor to detect detonation. Detonation is the premature ignition of the air and fuel mixture in your engine's cylinders, which you may know as pinging or knocking coming from the engine compartment. The spark knock sensor will adjust your engine's timing automatically when detonation is detected. If your engine is knocking or pinging, you may need to replace your spark knock sensor.
Open the hood of your vehicle. Let the engine cool since you will be working near the engine block, which can be very hot if the vehicle has been run recently.
Locate the knock sensor, which will be mounted on the engine block near the intake manifold with a wiring harness attached to it. Have your new sensor handy to use for comparison purposes when looking for the location of the old sensor.
Remove any engine components or brackets that may hinder the access for removing your spark knock sensor by backing out the holding bolts in a counterclockwise direction with an adjustable wrench. Use a digital camera to take pictures of components before disassembly to aide in their reinstallation.
Remove the wiring harness from the knock sensor by squeezing in on the tabs that hold the connector in place and pulling the harness away from the sensor. Move the wiring harness to one side.
Remove the sensor holding bolt with an adjustable wrench turned in a counterclockwise direction. Pull the sensor from the engine block by hand.
Push the new sensor into place on the engine block. Place the holding bolt backing into the sensor mounting hole and tighten it with an adjustable wrench in a clockwise direction. Push the wiring harness back onto the sensor until it snaps into place.
Replace any other components or brackets removed to access the sensor. Tighten the holding bolts with an adjustable wrench in a clockwise direction. Close the hood.
- Prolonged spark knock may damage your engine’s internal components. Replace a faulty spark knock detector as soon as possible to avoid costly repair bills.