Here's a general outline. This is not a complete guide, and specific steps may vary slightly depending on your exact engine (3.1L V6 or 3.8L V6). Always consult a repair manual specific to your vehicle's year and engine for precise instructions and diagrams.
Tools You'll Likely Need:
* Socket wrench set (metric)
* Wrenches (metric)
* Screwdrivers (Phillips and possibly flathead)
* Pliers
* Drain pan
* New thermostat (make sure it's the correct one for your engine)
* New thermostat gasket (if not included with the thermostat)
* Antifreeze/coolant (the correct type for your car)
* Rags or shop towels
* Funnel
General Steps:
1. Safety First: Let the engine cool completely before starting this job. Hot coolant can cause serious burns.
2. Drain the Coolant: Locate the radiator drain petcock (usually at the bottom of the radiator) and carefully open it to drain the coolant into your drain pan.
3. Remove the Upper Radiator Hose: Carefully detach the upper radiator hose from the radiator. Some coolant may still remain in the hose, so have rags handy.
4. Access the Thermostat Housing: This is the tricky part and varies depending on your engine. You'll likely need to remove some components to gain access. The repair manual will show you exactly what needs to be removed (potentially air intake components, hoses, etc.).
5. Remove the Thermostat Housing: Once you have access, carefully remove the thermostat housing bolts. The housing itself may contain the thermostat and gasket. Be prepared for some coolant to spill.
6. Replace the Thermostat and Gasket: Carefully remove the old thermostat and gasket. Inspect the housing for any damage. Clean the housing thoroughly. Install the new gasket (if needed) and the new thermostat, ensuring it's seated correctly.
7. Reinstall the Thermostat Housing: Carefully reinstall the thermostat housing and bolts, tightening them to the manufacturer's specifications (found in your repair manual).
8. Reattach the Upper Radiator Hose: Reconnect the upper radiator hose to the radiator.
9. Refill the Cooling System: Carefully add the correct type and amount of coolant to the radiator. Refer to your owner's manual for the proper coolant type and capacity. You may need to add coolant to the overflow reservoir as well.
10. Bleed the Air from the System: This is crucial to prevent overheating. Start the engine and let it run until the thermostat opens (you should see coolant flowing). Check for leaks. Top off coolant as needed. The procedure for bleeding the system might be different on various Intrigues, refer to your manual.
11. Test Drive: After everything is reassembled and the coolant is topped off, take the car for a short test drive to ensure the engine is operating at the correct temperature.
Important Considerations:
* Repair Manual: A repair manual specific to your 1999 Oldsmobile Intrigue is absolutely essential. It will provide detailed instructions, diagrams, torque specifications, and other vital information. You can find these online or at auto parts stores.
* Engine Differences: The 3.1L and 3.8L V6 engines in the 1999 Intrigue have different configurations. The access to the thermostat housing and the steps involved will differ slightly.
* Coolant Type: Use the correct type of coolant specified for your vehicle. Mixing different types of coolant can damage your engine.
This is a general overview, and it's strongly recommended to consult a repair manual before attempting this repair. If you're uncomfortable working on your car, it's always best to take it to a qualified mechanic. Improper repair can lead to engine damage.
