Here's how to test it:
1. Visual Inspection (Easy and First):
* Location: Find the thermostat housing. This is usually located on the upper radiator hose, near the engine. Consult your repair manual for the exact location on your Cirrus.
* Check for Obvious Issues: Look for cracks, leaks, or damage to the thermostat housing itself. A damaged housing can lead to problems even if the thermostat is fine.
2. Testing the Thermostat (Requires Removal):
* Removal: You'll need to drain some coolant (consult your repair manual for the procedure). Then remove the thermostat housing. This usually involves removing a few bolts or clamps.
* Boiling Water Test (Most Common):
* Fill a pot with water and bring it to a rolling boil.
* Place the thermostat in the boiling water (carefully!).
* Observe: A functioning thermostat should fully open at its rated temperature (usually around 195°F or 90°C for a Cirrus, but check your specific thermostat). If it doesn't open fully, it's likely faulty.
* Note: Some thermostats are designed to open gradually, but there should be noticeable opening. If it's stuck completely closed, it's definitely bad.
* Alternative Test (Using a Thermometer and Pot): Use a thermometer to monitor the water temperature as it heats. You should see the thermostat open at its specified temperature.
3. Testing the Thermostat in the Vehicle (More Advanced):
This method tests the thermostat's operation *in situ* but requires more advanced knowledge and tools. It involves monitoring coolant temperature with a scan tool as the engine warms up. A properly functioning thermostat will show a consistent temperature rise until it opens, then the temperature will stabilize. This requires:
* OBD-II Scan Tool: To monitor coolant temperature.
* Knowledge of using the scan tool: This isn't a simple plug-and-play test.
Important Considerations:
* Repair Manual: A repair manual specific to your 2000 Chrysler Cirrus is invaluable. It will show you exactly where the thermostat is located, how to remove it, and the proper torque specifications for reassembly.
* Coolant: Use the correct type and amount of coolant when refilling the system. Mixing coolant types can be detrimental.
* Air Pockets: After replacing the thermostat, carefully bleed the cooling system to remove any air pockets that can impede cooling.
If you are not comfortable performing these tests or repairs yourself, it is best to take your vehicle to a qualified mechanic. Working on a cooling system involves hot coolant and can be dangerous if not handled properly. Incorrectly diagnosing or repairing a thermostat can lead to engine overheating and significant damage.
