GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Buick 🢒 2003 🢒 LeSabre 🢒 Engine 🢒 Engine Controls - 3.8L 🢒 Knock Sensor 2 Replacement

Removal Procedure

    Object Number: 381311 Size: SH
  1. Turn OFF the ignition switch.

    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.

  2. Raise the vehicle. Refer to Lifting and Jacking the Vehicle in General Information.
  3. Remove the bolts from the splash shield.

    4. 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.

  4. Drain the cooling system. Refer to Cooling System Draining and Filling in Engine Cooling.
  5. Remove the bolts (2) from the knock sensor heat shield (1) located under the freeze plug, or the block heater if equipped.
  6. Disconnect the electrical connector (3) from the knock sensor (4).

    7. Object Number: 389301 Size: SH
  7. Remove the knock sensor (2) from the engine block (1).

Installation Procedure

    Object Number: 389301 Size: SH

    Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

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

  1. Install the knock sensor (2) into the engine block (1).

    2. Tighten
    Tighten the knock sensor to 19 N·m (14 lb ft).

  2. Install the knock sensor heat shield

    3. Tighten
    Tighten the bolts to 60 N·m (44 lb ft).

  3. Connect the electrical connector to the knock sensor.
  4. Install the splash shield.
  5. Lower the vehicle.
  6. Fill the cooling system. Refer to Cooling System Draining and Filling in Engine Cooling.
  7. Check the coolant level.