How to Flush the Radiator in a Pontiac Grand Prix

How to Flush the Radiator in a Pontiac Grand Prix. When trying to keep a Pontiac Grand Prix in proper operating condition, it's necessary to perform regular maintenance. One example of this routine maintenance is the flushing of the radiator. If you can operate a wrench and follow directions, then you can complete this maintenance with relative ease.

Things You'll Need:

• Distilled water
• Crescent wrench
• Coolant
• Rags
• Bucket
• Sealable container

1. Move the Pontiac Grand Prix to a level area and set the parking brake

Move the Pontiac Grand Prix to a level area and set the parking brake. Then, pop the hood and touch the radiator. If it's warm to the touch, allow it to cool off before you continue.

2. Twist the radiator cap one full turn

Twist the radiator cap one full turn. Then, step back to make sure it doesn't erupt from internal pressure. Even when radiators are cool to the touch, they can still pose a risk of spewing coolant on anyone in the area.

3. Place a bucket underneath the radiator and blow the drain plug

Place a bucket underneath the radiator and blow the drain plug. Make sure the bucket can hold 2 gallons of liquid. The drain plug on a Pontiac Grand Prix is usually on the driver's side bottom of the radiator facing the engine. However, on some models the drain plug is on the front of the radiator.

4. Loosen the drain plug and allow the old coolant to drain completely

Loosen the drain plug and allow the old coolant to drain completely from the radiator into the bucket. You may need a crescent wrench to loosen the drain plug.

5. Dispose of the old coolant by pouring it into a sealable container

Dispose of the old coolant by pouring it into a sealable container. Place the bucket back under the drain plug when you finish. Because coolant is extremely toxic to people and pets, you need to very careful with it during the radiator flush.

6. Shut the radiator drain plug and fill the radiator with distilled water

Shut the radiator drain plug and fill the radiator with distilled water. Loosen the plug to drain the water and then, replicate this process of filling and draining until the water runs free of debris into the bucket. You can use tap water from a garden hose, but this water may damage your coolant system by leaving sediment behind in the radiator.

7. Close the drain plug and fill the radiator with fresh coolant

Close the drain plug and fill the radiator with fresh coolant until it's about an inch from overflowing. You will need 3 gallons of coolant for the regular Pontiac Grand Prix model and 4 for the GXP model. Be sure to check the drain plug for any leakage.

8. Start the Pontiac Grand Prix and turn the heating system to high

Start the Pontiac Grand Prix and turn the heating system to high. Allow the car to keep running until the cooling fan turns on twice. After that happens, switch off the engine and check the coolant level. If it went down, add more coolant. If not, put the radiator cap back on and close the hood.

Video showing how to flush the heater core of a Grand Prix:

Helpful comments on this video:

• You’re the man! Tried everything to get my heat back. This fixed it as soon as I started driving it after the flush. Easy instructions. Lifesaver
• This video helped me go from zero heat on my 2005 pontiac grand am, to blasting heat. Thank you so much. Lessons learned: 1. If your driveway is slanted up, back in instead of pull in. When I pulled the hose from the engine block (on grand am), the coolant leaked EVERYWHERE because of the slant on the hill. 2. The hose clamps by GM are a PITA without the right tool to move them. I ended up throwing one about a 100 feet after I finally got it off, and I put a replacement hose clamp on (2 for $3 at autozone) that simply screws tight.