Saturn Coupes/Sedans/Wagons 1991-1998 Repair Guide

Heater Core

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REMOVAL & INSTALLATION



See Figures 1, 2, 3, 4, 5 and 6

The Saturn Heating Ventilation Air Conditioning (HVAC) module is the same basic unit on all models, regardless of whether or not they are equipped with air conditioning. The module contains the blower motor, heater core, A/C evaporator (if equipped) and various valve/seal assemblies which route fresh or passenger compartment air by the A/C evaporator and/or the heater core.

  1. Disconnect the negative battery cable, then drain the engine cooling system into a suitable container.
  2.  
  3. Raise the front of the vehicle and support it safely using jackstands.
  4.  
  5. While squeezing the retaining tabs, move the heater core clamps up the hoses and off the fittings, then remove the jackstands and carefully lower the vehicle.
  6.  
  7. For the DOHC engine, remove the air cleaner housing cover and disconnect the air induction hose at the intake manifold. For the SOHC engine, remove the air cleaner housing assembly.
  8.  
  9. Carefully remove the hoses from the heater core. Never pry hoses against the heater core pipes or the core may be damaged. Using compressed air or a length of clean hose, blow the remaining coolant out of the heater core to prevent spilling it in the vehicle' interior.
  10.  
  11. Remove the left and right lower trim lower trim panel extensions by disconnecting the Velcro at the bottom of the panels and pulling them out of the upper retaining clips.
  12.  
  13. If equipped, remove the instrument panel lower closeout panel by pulling out at the top edge and rotating downward.
  14.  
  15. Remove the retaining screws and lower the heater duct straight downward. Carefully slide the duct to the side and remove it from the vehicle. Make sure the heater duct-to-rear floor duct seal is not damaged during removal.
  16.  
  17. Push down on the cable and lift the plastic tab to release the temperature cable hold-down clip, then disconnect the temperature cable by squeezing the valve pin and pulling the cable straight off the HVAC module.
  18.  
  19. Locate the heater core side cover, on the driver' side of the HVAC module, then remove the retaining screws and the side cover.
  20.  
  21. Remove the screws and the lower heater core cover. Remove the screw from the heater core pipe clamp.
  22.  
  23. Remove the screw and the lower core retainer, then carefully remove the heater core from the vehicle.
  24.  

To install:
  1. Install the heater core, being careful not to damage the pipe seal. Use a coating of petroleum jelly to ease installation of the pipes through the cowl.
  2.  
  3. Install the lower heater core retainer and the pipe clamp using the retaining screws. Install the lower and side covers.
  4.  
  5. Push the temperature cable over the pin and snap the cable hold-down clip over the cable holder.
  6.  
  7. Slide the heater duct in sideways and raise it into position, being careful not to damage the rear floor heater seal. Install the duct screws.
  8.  
  9. Install the left and right trim panel extensions.
  10.  
  11. Install the instrument panel closeout panel, if equipped.
  12.  
  13. Raise the front of the vehicle and support it safely using jackstands.
  14.  
  15. Install the heater hoses, positioning the left hose clamp tangs to the 7-8 o'clock position and the right hose clamp tangs to the 6 o'clock position.
  16.  



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Fig. Fig. 1: Slide the retaining clamps upward on the heater core hoses until they no longer compress the hoses on the fittings



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Fig. Fig. 2: After removing the lower duct fasteners, carefully drop the duct downward and slide it sideways, removing the duct from the vehicle



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Fig. Fig. 3: Remove the temperature cable from the HVAC module

  1. If not done already, install the radiator drain plug, then install the cylinder block drain plug and tighten the block plug to 26 ft. lbs. (35 Nm).
  2.  
  3. Remove the jackstands and carefully lower the vehicle, then install the air cleaner housing components, as applicable.
  4.  
  5. Connect the negative battery cable and properly fill the engine cooling system.
  6.  
  7. Pressure test the cooling system or start the engine and check for leaks.
  8.  



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Fig. Fig. 4: Remove the screw from the heater core pipe clamp



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Fig. Fig. 5: Remove the lower heater core retainer, then carefully remove the heater core from the HVAC module



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Fig. Fig. 6: The same basic HVAC module is used on all Saturn vehicles, regardless of whether or not they are equipped with A/C. On vehicles not equipped with A/C, the evaporator is absent

 
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