GM Service Manual Online
For 1990-2009 cars only

Caution: Hot engine coolant may cause severe burns. Although the cooling system has been drained, coolant still remains in the engine water jacket. This coolant will drain with the removal of the knock sensor.

Removal Procedure


    Object Number: 12755  Size: SH
  1. Remove the negative battery cable.
  2. Caution: Unless directed otherwise, the ignition and start switch must be in the OFF or LOCK position, and all electrical loads must be OFF before servicing any electrical component. Disconnect the negative battery cable to prevent an electrical spark should a tool or equipment come in contact with an exposed electrical terminal. Failure to follow these precautions may result in personal injury and/or damage to the vehicle or its components.

  3. Raise vehicle.
  4. Remove the splash shield, drain cooling system. Refer to Cooling and Radiator.
  5. Remove the knock sensor heat shield mounting bolt located under freeze plug (or block heater if equipped).
  6. Remove the knock sensor wiring harness connector from knock sensor.
  7. Remove the knock sensor from the engine block.

Installation Procedure

Important: Do Not apply thread sealant to sensor threads. The sensor is coated at factory and applying additional sealant will affect the sensors ability to detect detonation.


    Object Number: 12755  Size: SH
  1. Install the knock sensor into engine block.
  2. Tighten
    Tighten the knock sensor to 19 N·m (14 lb ft).

  3. Install the knock sensor heat shield mounting bolt located under the freeze plug (or block heater if equipped).
  4. Install the knock sensor wiring harness connector to the knock sensor.
  5. Install the splash shield.
  6. Lower the vehicle.
  7. Fill the cooling system. Refer to Cooling and Radiator.
  8. Connect the negative battery cable.