Tools You'll Need:
* New Thermostat: Make sure you get the correct one for your specific engine (likely a 1.8L or 2.2L).
* Socket Set: Various sizes, including a deep well socket for the thermostat housing bolts.
* Wrench Set: May be needed for some bolts or hose clamps.
* Pliers: For hose clamps.
* Drain Pan: To catch coolant.
* Funnel: To refill the cooling system.
* Gloves: To protect your hands.
* Shop Rags or Paper Towels: For cleaning up spills.
* Coolant: 50/50 mix of coolant and distilled water (check your owner's manual for the correct type).
Procedure:
1. Safety First: Let the engine cool completely before starting. The coolant will be hot and under pressure.
2. Drain the Coolant: Locate the radiator drain petcock (usually at the bottom of the radiator). Place your drain pan underneath and carefully open the petcock to drain the coolant.
3. Locate the Thermostat Housing: The thermostat housing is usually located on the engine block, near the top of the engine. It's a metal or plastic housing with bolts holding it in place.
4. Disconnect the Upper Radiator Hose: Carefully disconnect the upper radiator hose from the thermostat housing. You may need pliers to loosen hose clamps. Have a rag ready to absorb any remaining coolant.
5. Remove the Thermostat Housing Bolts: Use your socket set to carefully remove the bolts holding the thermostat housing in place.
6. Remove the Thermostat Housing: Gently lift the thermostat housing off the engine block. The thermostat should be visible inside the housing.
7. Remove the Old Thermostat: The thermostat is usually held in place by a small spring clip. Carefully remove the old thermostat. Inspect the gasket for damage; replace if necessary.
8. Install the New Thermostat: Carefully install the new thermostat, ensuring the gasket is properly seated. Make sure the thermostat is oriented correctly (usually has an arrow indicating flow direction).
9. Reinstall the Thermostat Housing: Carefully reinstall the thermostat housing, ensuring the gasket is properly seated. Tighten the bolts to the manufacturer's specifications (consult your repair manual).
10. Reconnect the Upper Radiator Hose: Reattach the upper radiator hose to the thermostat housing, ensuring the hose clamp is securely fastened.
11. Refill the Cooling System: Carefully refill the radiator with the 50/50 coolant mixture using your funnel. Add coolant until it reaches the fill line.
12. Bleed the Air from the Cooling System: This is crucial to prevent overheating. Consult your repair manual for the specific bleeding procedure for your Cavalier. This usually involves running the engine for a few minutes, then checking the coolant level and adding more as needed.
13. Check for Leaks: After refilling and bleeding, carefully inspect all connections for leaks.
14. Test Drive: Once you're confident everything is secure and the cooling system is properly filled, start the engine and let it run for a while. Monitor the temperature gauge and check for any leaks. Take a short test drive to ensure the engine reaches operating temperature without overheating.
Important Considerations:
* Repair Manual: A repair manual specific to your 1998 Chevy Cavalier is highly recommended. It will provide detailed instructions, diagrams, and torque specifications.
* Coolant Type: Use the correct type of coolant recommended by your owner's manual. Mixing different types of coolant can damage your engine.
* Safety: Always wear safety glasses and gloves when working on your vehicle.
If you are not comfortable performing this repair yourself, it's best to take your car to a qualified mechanic. Improperly replacing a thermostat can lead to engine damage.
