Safety First!
* Hot coolant burns severely. Let the engine cool completely before starting. This could take several hours.
* Wear safety glasses and gloves. Coolant is corrosive.
* Work in a well-ventilated area. Coolant fumes are toxic.
* Have a drain pan large enough to hold at least 8 quarts of fluid. (Capacity may vary slightly)
* Dispose of used coolant properly. Check your local regulations for proper disposal methods; most auto parts stores will accept used coolant for recycling.
Tools and Materials:
* New coolant (50/50 mix of coolant and distilled water, or pre-mixed coolant. Check your owner's manual for the correct type – usually Dex-Cool for GM vehicles)
* Drain pan
* Wrench for the radiator drain plug (usually 8mm or 10mm)
* Funnel
* Hose clamps (if replacing hoses)
* New coolant hoses (if needed)
* Clean rags
* Jack and jack stands (recommended, but not always necessary)
* Optional: Coolant flush kit (recommended for best results)
Procedure:
1. Locate the Radiator Drain Plug: This is usually located at the bottom of the radiator, on the driver's side.
2. Prepare for Draining: Place your drain pan under the radiator drain plug.
3. Drain the Coolant: Carefully loosen and remove the radiator drain plug. Let the coolant drain completely.
4. Locate the Engine Block Drain Plug: Many engines also have a drain plug on the engine block. If your Grand Prix does, locate and remove this plug as well, allowing the coolant to drain into your pan.
5. Remove Pressure (If applicable): Some vehicles have a pressure cap on the overflow tank. If your Grand Prix has one, carefully release pressure by slowly twisting the cap counterclockwise *after* the engine is cold. If it's pressurized, it might hiss or spit a little coolant, so be careful.
6. Optional: Flush the Cooling System: A coolant flush kit will circulate cleaner through the system, removing more sediment and old coolant. Follow the instructions for the kit you purchase. If skipping this step, you'll rely on multiple drain and refill cycles to remove as much old coolant as possible.
7. Refill the Radiator: Once draining is complete, carefully replace the drain plugs (engine block and radiator). Using a funnel, add the 50/50 mix of coolant and distilled water (or pre-mixed coolant) to the radiator until it's nearly full (check your owner's manual for the exact amount).
8. Run the Engine: Start the engine and let it run until the thermostat opens (usually around 180-200°F/82-93°C, monitor temperature gauge). This will circulate the new coolant through the engine block and heater core. Allow the engine to run for about 15-20 minutes.
9. Check Coolant Level: Turn off the engine and let it cool completely. Check the coolant level in the radiator and add more coolant if necessary. Check and top off the overflow reservoir as well.
10. Check for Leaks: Inspect for any leaks around the drain plugs, hoses, and clamps.
11. Repeat if Necessary: If you skipped the flush, repeat steps 6 through 10 to get as much of the old coolant out as possible.
Important Considerations:
* Air Pockets: Air pockets in the cooling system can cause overheating. Make sure to bleed the air out of the system as instructed in your owner's manual. Often, this involves squeezing hoses or opening bleed valves.
* Coolant Type: Use the correct type of coolant specified in your owner's manual. Mixing different types of coolant can lead to problems.
* Hose Condition: While you have the system open, inspect the hoses for cracks or deterioration. Replace any hoses that look worn.
Remember, this is a general guide. Refer to your owner's manual for year-specific instructions and torque specifications. If you are uncomfortable performing this task yourself, it's always best to take your vehicle to a qualified mechanic.
