GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 1999 🢒 Corvette 🢒 Engine 🢒 Engine Cooling 🢒 Coolant Heater Replacement

Coolant Heater Replacement Dealer Installation

Removal Procedure
  1. Drain the engine coolant from the engine block into an approved container.

    2. Object Number: 581687 Size: SH
  2. Disconnect the engine coolant heater cord from the engine coolant heater.

    3. Object Number: 65332 Size: SH
  3. Take care not to damage the surface of the opening in the engine block.

    4. Remove the engine coolant heater from the engine block.

  4. Clean the opening in the engine block, remove any burrs, sealing compound, or paint.

Installation Procedure

    Important: The engine coolant heater sealing washer may be reused if not bent, scored or otherwise damaged.


    Object Number: 65332 Size: SH
  1. Apply a 3.175 mm (0.125 in) bead of sealant GM P/N 12346004 or equivalent to the face of the engine coolant heater sealing washer.
  2. Install the engine coolant heater sealing washer to the engine coolant heater.
  3. Insert the engine coolant heater into the engine block.

    4. 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.

  4. Tighten the engine coolant heater to the engine block.

    5. Tighten
    Tighten the engine coolant heater to 40 N·m (30 lb ft).


    Object Number: 65332 Size: SH

    Important: The engine coolant heater cord (2) must not touch the engine, hot pipes, manifold or any moving parts. Always keep the electrical cord neatly rolled up with the end of the cord (1) tucked in the center of the coil and secured in place with the fastener supplied.

  5. Push the engine coolant heater cord eletrical connector firmly into the engine coolant heater.
  6. Refill the cooling system. Refer to Cooling System Draining and Filling .
  7. Inspect the area around the engine coolant heater for coolant leaks.