However, if you're determined to do it yourself, here's a general outline. This is not a complete, step-by-step guide, and specific instructions may vary slightly depending on your Cavalier's trim level. Always consult a repair manual specific to your year and model for precise instructions and torque specifications. A Haynes or Chilton manual is a good investment for this type of work.
General Steps (This is a simplified overview, actual steps are far more detailed):
1. Safety First: Disconnect the negative battery terminal. Wear safety glasses and gloves. Work in a well-ventilated area.
2. Drain Coolant: Locate the drain valve on the engine block (usually near the bottom of the radiator) and the coolant overflow tank. Open the drain valve and let the coolant drain completely into a suitable container.
3. Prepare the Dashboard: This is the most labor-intensive part. You'll need to remove significant portions of the dashboard, including the glovebox, possibly parts of the center console, and possibly the steering column shroud. This often involves removing many screws, clips, and potentially disconnecting electrical connectors. Carefully document everything as you go, taking pictures if necessary. Refer to a repair manual for precise instructions on dashboard disassembly.
4. Access the Heater Core: Once the dashboard is partially disassembled, you should gain access to the heater core, which is usually located behind the dashboard, within the HVAC housing.
5. Disconnect the Heater Core Hoses: Carefully disconnect the coolant hoses connected to the heater core. Have a container ready to catch any remaining coolant.
6. Remove the Heater Core: This often involves removing the HVAC housing or at least unbolting or unclipping the heater core from its mounting location. The access is usually very tight and awkward.
7. Install the New Heater Core: Carefully install the new heater core in the reverse order of removal, ensuring it's properly seated and aligned.
8. Reconnect the Hoses: Reconnect the coolant hoses, ensuring they are securely clamped.
9. Reassemble the Dashboard: Carefully reassemble the dashboard, ensuring all parts are properly aligned and secured. Reconnect any electrical connectors.
10. Refill Coolant: Refill the cooling system with the correct type and amount of coolant. Use a 50/50 mix of coolant and distilled water.
11. Bleed the Cooling System: This is crucial to remove air pockets from the system. Run the engine with the heater on high until the thermostat opens and the system is fully bled. Check for leaks.
12. Test: Test the heater to ensure it's working properly. Check for leaks again after driving the car for a while.
Crucial Considerations:
* Repair Manual: A repair manual is absolutely essential. The steps outlined above are a very general overview.
* Patience: This is a time-consuming job. Be prepared to spend several hours, possibly even a day or more.
* Tools: You'll need a variety of tools, including screwdrivers (Phillips and flathead), sockets, wrenches, pliers, and possibly specialized tools for removing dashboard clips.
* Coolant: Have enough coolant on hand to refill the system.
* Parts: Ensure you have the correct replacement heater core for your vehicle.
Again, this is a challenging repair. If you're not comfortable with this type of work, it's best to leave it to a professional mechanic. Improper installation can lead to further damage or even injury.
