Coolant Heater Replacement 3.1L

1. Drain the cooling system. Refer to Cooling System Draining and Filling .
2. Raise and suitably support the vehicle. Refer to Lifting and Jacking the Vehicle in General Information.
3. Disconnect the engine coolant heater cord from the engine coolant heater.
4. Loosen the engine coolant heater bolt. Do not remove the engine coolant heater bolt.
5. Remove the engine coolant heater.
6. Clean the engine coolant heater opening.

1. Coat the following components with the lubricant GM P/N 12345996 or the equivalent:

•	The engine block heater seal

•	The cleaned surface of the engine block heater hole

2. Install the engine coolant heater. Position the engine coolant heater element at the 3 o'clock position (2), as shown.

Final installed position between 2 o'clock (1) and 4 o'clock (3) is acceptable.

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.

3. Tighten the engine coolant heater bolt.

Tighten
Tighten the engine coolant heater bolt to 2 N·m (18 lb in).

4. The engine coolant heater cord must not touch the engine , hot pipes, manifold, or any moving parts. Secure the engine coolant heater cord with tie straps as required.

Connect the engine coolant heater cord to the engine coolant heater.

5. Lower the vehicle.
6. Fill the cooling system. Refer to Cooling System Draining and Filling .
7. Inspect for leaks.

Coolant Heater Replacement 3.8L

1. Drain the engine coolant. Refer to Cooling System Draining and Filling .
2. Raise and suitably support the vehicle. Refer to Lifting and Jacking the Vehicle in General Information.
3. Remove the coolant heater cord from the coolant heater.



4. Loosen the bolt at the coolant heater but do not remove.
5. Remove the coolant heater.
6. Remove and clean any burrs, compound, paint, or rough spots from the core plug hole.

1. Apply a coat of Permatex® Thread Sealant with Teflon to the O-ring and clean the surface of the plug opening.
2. Install the coolant heater by pushing tight to the block.



3. Install the coolant heater so the element is positioned as shown.

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 coolant heater bolt until both locking wings draw tight against the inner wall of the engine block.

Tighten
Tighten the coolant heater bolt to 2 N·m (18 lb in).

Notice: The heater cord must not touch the engine, hot pipes, manifold, or any moving parts. Route the cord to the left front of the engine compartment securing with tie straps as necessary to prevent damage.

5. Install the coolant heater cord to the coolant heater.
6. Fill the cooling system. Refer to Cooling System Draining and Filling .
7. Inspect for leaks.