The knock sensor is a device that is designed to sense vibrations coming from the engine. It is located on the engine block. The Jeep Wrangler's computer takes the signals from the sensor and alters the the ignition timing to prevent misfires and detonation. If your knock sensor is going bad, you will experience a loss in MPG and a lack of acceleration at higher speeds. Replacing this sensor is not hard, it just requires you to slide under the car and get a bit messy. If your engine's timing is off, your MPG has decreased, or your acceleration doesn't feel normal, then connect an OBD-II to your Wrangler and see if the knock sensor is in fact faulty. Read on to learn how you can replace it yourself.
Materials Needed
This is not required; however, raising your Jeep's front will give you much more room to work in. Raise the front of the car from the axles, and secure it with jack stands.
Figure 1. Raise the Jeep.
Step 2 – Remove knock sensor
The knock sensor is located on the engine block. It is located just behind the right side engine mount (passenger's side). The engine mount holds the engine to the frame. So find the sensor between the mount, the transmission, and the oil pan.
Remove the electrical connection by squeezing it and pulling it out. Then remove the bolt holding it to the engine block.
Figure 2. Knock sensor.
Step 3 – Install the new knock sensor
Installation is the reverse of removal.
Connect the electrical harness to the sensor and tighten its bolt to 176 in. lbs (15 ft./lbs).
In Figure 3, number 1 is the electrical connection, number 2 is the bolt holding the sensor to the block, and number 4 is the sensor itself.
Figure 3. Install new sensor.
Materials Needed
- 12mm wrench
- New knock sensor
- Jack and jack stands
This is not required; however, raising your Jeep's front will give you much more room to work in. Raise the front of the car from the axles, and secure it with jack stands.
Figure 1. Raise the Jeep.
Step 2 – Remove knock sensor
The knock sensor is located on the engine block. It is located just behind the right side engine mount (passenger's side). The engine mount holds the engine to the frame. So find the sensor between the mount, the transmission, and the oil pan.
Remove the electrical connection by squeezing it and pulling it out. Then remove the bolt holding it to the engine block.
Figure 2. Knock sensor.
Step 3 – Install the new knock sensor
Installation is the reverse of removal.
Connect the electrical harness to the sensor and tighten its bolt to 176 in. lbs (15 ft./lbs).
In Figure 3, number 1 is the electrical connection, number 2 is the bolt holding the sensor to the block, and number 4 is the sensor itself.
Figure 3. Install new sensor.