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

    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.

  1. Disconnect the negative battery cable.
  2. Caution: To avoid any vehicle damage, serious personal injury or death when major components are removed from the vehicle and the vehicle is supported by a hoist, support the vehicle with jack stands at the opposite end from which the components are being removed and strap the vehicle to the hoist.

  3. Raise and support the vehicle.
  4. Remove the splash shield. Refer to Engine Splash Shield Replacement in Body Front End.
  5. Drain the cooling system. Refer to Cooling System Draining and Filling in Engine Cooling.
  6. Remove the mounting bolt located under the freeze plug (or the block heater, if equipped) from the knock sensor heat shield.
  7. Remove the wiring harness connector from the knock sensor.
  8. Remove the knock sensor from the engine block.

Installation Procedure

Important:  DO NOT apply thread sealant to the sensor threads. The sensor is coated at the factory and applying additional sealant affects the sensor's ability to detect detonation.


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

  3. Install the mounting bolt to the knock sensor heat shield.
  4. Connect the wiring harness connector to the knock sensor.
  5. Install the splash shield. Refer to Engine Splash Shield Replacement in Body Front End.
  6. Lower the vehicle.
  7. Fill the cooling system. Refer to Cooling System Draining and Filling in Engine Cooling.
  8. Connect the negative battery cable.