GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Buick 🢒 1996 🢒 Park Avenue 🢒 Engine 🢒 Engine Cooling 🢒 Engine Coolant Thermostat Replacement

Removal Procedure

    Notice: When adding coolant, use DEX-COOL® coolant. If silicated coolant is added to the system, premature engine, heater core or radiator corrosion may result. In addition, the engine coolant will require change sooner-at 50 000 km (30,000 mi) or 24 months.

  1. Remove the engine cover.
  2. Disconnect the negative battery cable. Refer to

    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.

    in General Information.
  3. Partially drain the coolant to a level below the thermostat. Refer to Cooling System Draining and Filling .

    4. Object Number: 46166 Size: SH
  4. Disconnect the upper radiator hose.

    5. Object Number: 46168 Size: SH
  5. Remove the thermostat housing bolts (1) and the thermostat housing(2).
  6. Remove the gasket (3) and the thermostat (4).
  7. Clean the gasket mating surfaces.

Installation Procedure

    Object Number: 46168 Size: SH
  1. Install the thermostat (4) using a new gasket (3).
  2. Install the thermostat housing (2) and the thermostat housing bolts (1).

    3. Tighten
    Tighten the thermostat housing bolts to 20 N·m (15 lb ft).

    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.


    Object Number: 46166 Size: SH
  3. Connect the upper radiator hose and clamp to the thermostat housing.
  4. Refill the cooling system. Refer to Cooling System Draining and Filling .
  5. Connect the negative battery cable.

    6. Tighten
    Tighten the negative battery cable bolt to 15 N·m (11 lb ft).

  6. Install the engine cover.
  7. Start the engine. After the engine reaches normal operating temperature, check for coolant leaks.