How to Use Green Prestone in a GM Vehicle

Certain GM vehicles use Dex-Cool by Prestone, which is the orange antifreeze. GM requires this because many of its newer engines are aluminum. The green Prestone is used in the older engines (circa pre-1990), and it can be used in the newer engines, but is not recommended. If you would like to use the green antifreeze, you should change it every year.

Things You'll Need

• Drain pan
• Screwdriver
• Garden hose

Instructions

1. Slide the drain pan under the radiator petcock. Loosen the petcock and allow the radiator to drain. Dispose of the antifreeze in an acceptable manner. Place the drain pan under the top radiator hose. Loosen the clamp at the radiator, then aim the hose down to the drain pan.

2. Stick the garden hose into the radiator. Start the vehicle and allow it to come to normal operating temperature. When antifreeze starts draining from the upper hose, turn the water hose on. The water will circulate through the engine, flushing the old antifreeze out and into the drain pan. When the water runs clear, turn the engine and garden hose off.

3. Reinstall the top radiator hose. Tighten the petcock. Fill the radiator with 50 percent green Prestone antifreeze and 50 percent water if the antifreeze is full strength. If the antifreeze is labeled "50/50," fill the radiator with the mixture.

4. Start the vehicle and allow it to come to operating temperature. As it does, the thermostat will open and the water will begin circulating again. Top off the radiator as needed.

Tips & Warnings

• Always keep an eye on the engine temperature while doing this. If the engine temperature starts to higher than 225 degrees, shut the engine off.

• The water from a warm engine will be hot. Take appropriate precautions.

• Never open the radiator cap, petcock or loosen the hose when the engine is hot, as the system is under pressure. Wait until the engine is cool before beginning this process.