How to replace heater core on 2006 Chevy Cobalt?

HEATER CORE.

Removal & Installation

With a pressurized cooling system, the coolant temperature in the radiator can be considerably higher than the boiling point of the solution at atmospheric pressure. Removal of the surge tank cap, while the cooling system is hot and under high pressure, causes the solution to boil instantaneously with explosive force. This will cause the solution to spew out over the engine, the fenders, and the person removing the cap. Serious bodily injury may result.

1. Before servicing the vehicle, refer to the Precautions Section.
2. Drain the cooling system.
3. Raise and support the vehicle.
4. Place a drain pan under the water pump drain port.
5. Loosen the water pump drain bolt and drain the coolant from the water pump.
6. Close and tighten the water pump drain bolt. Tighten the water pump drain bolt to 88 inch lbs. (10 Nm).
7. Lower the vehicle.
8. Reposition the heater outlet hose clamp at the heater core.
9. Remove the heater outlet hose from the heater core.
10. Reposition the heater inlet hose clamp at the heater core.
11. Remove the heater inlet hose from the heater core.
12. Remove the right console extension panel.
    
    
    

    

    Fig. Body control module
13. Remove the Body Control Module (BCM) from the vehicle.
14. Remove the front floor console left side extension panel.
15. Pull back the carpet at the bottom of the left Instrument Panel (I/P) center support bracket and remove the left I/P center support bracket nuts.
16. Remove the left I/P center support bracket.
17. Remove the accelerator control pedal from the front of the dash and position out of the way.
18. Raise the center floor outlet duct while pushing the floor ducts down to disengage the ducts.
19. Rotate the center floor outlet duct forward in the vehicle and pull down to disengage it from the HVAC module.
    
    
    

    

    Fig. Heater core cover removal
20. Remove the heater core cover heat stakes with a small chisel.
21. Loosen the nut that is behind the fuel line bracket and remove the stud from the dash panel at the heater hoses.
    
    NOTE

    Make certain that all of the heater core cover screws are removed before attempting to remove the heater core cover.
22. Pull the heater core cover down just enough to clear the locating pins from the HVAC module. Slide the heater core cover rearward until the drain tube clears the front of dash. Slide the heater core cover down, rearward, and to the right to remove.
    
    
    

    

    Fig. Heater core removal
23. Remove the heater core.

To install:

1. Inspect the foam heater core seal on the lower HVAC case. If damaged, replace using Kent Industries adhesive black foam tape P/N 46480, or equivalent.
2. Install the heater core into the HVAC module.
3. Install a new drain tube seal onto the drain tube.
   
   NOTE

   Spraying the heater core seal and the dash mat with a soap and water mixture will ease installation.
4. Install the heater core cover from the right side. Slide up and forward into position. Align the drain tube with the hole in the front of dash. Raise the heater core cover into position while aligning holes with the locating pins from the HVAC module.
5. Cut the sound insulator at the cowl near the center screw approximately 3 inch (76mm) and fold the sound insulator back to ease in installation of the screw. Ensure the sound insulator is positioned back after the screws are tightened.
   
   NOTE

   Make certain that the heater core cover is properly positioned and is fully seated on the HVAC module before installing the screws. Be sure to install all heater core cover screws.
6. Install the heater core cover screws. Tighten the heater core cover screws to 15 inch lbs. (2 Nm).
7. Install the stud into the dash panel at the heater hoses and tighten the nut that is behind the fuel line bracket.
8. Align the center floor duct with the HVAC module.
9. Push the center floor duct up while rotating rearward in the vehicle to install on the HVAC module.
10. Push down on the floor duct while rotating the center floor outlet ducts to align the ducts.
11. Slide the center floor outlet duct down into position in the floor ducts.
12. Install the accelerator control pedal.
13. Pull back the carpet and place the left center support bracket into position.
14. Install the left center support bracket nuts. Tighten the left center support bracket nuts to 88 inch lbs. (10 Nm).
15. Install the left side front floor console extension panel.
16. Install the BCM to the vehicle.
17. Install the heater outlet hose to the heater core.
18. Install the hose clamp to secure the hose.
19. Install the heater inlet hose to the heater core.
20. Install the hose clamp to secure the hose.
21. Fill the cooling system.