This vehicle has a newly developed engine coolant. GM Goodwrench® DEX-COOL® was developed to last for 240 000 km (150,000 mi) or 5 years, whichever occurs first. Follow the instructions in Draining and Filling Cooling System. Make sure only GM Goodwrench® DEX-COOL® (silicate-free) or Havoline® DEX-COOL® is used when coolant is added or changed.
A 50/50 mixture of ethylene glycol ( DEX-COOL®) and water will provide the following protection:
| Notice: Pure coolant can be added to raise the boiling point of the coolant, but too much will affect the freezing point. Do not use a solution stronger than 70 percent, as the freeze level rises rapidly after this point. Pure coolant will freeze at -22°C (-8°F). |
| • | Give freezing protection down to -37°C (-34°F). |
| • | Give boiling protection up to 129°C (260°F). |
| • | Protect against rust and corrosion. |
| • | Help keep the proper engine temperature. |
| • | Let the warning lights and gauges work correctly. |
Notice: Pure coolant can be added to raise the boiling point of the coolant, but too much will affect the freezing point. Do not use a solution stronger than 70 percent, as the freeze level rises rapidly after this point. Pure coolant will freeze at -22°C (-8°F).
The L47 uses a DEX-COOL® and GM coolant supplement (sealant) GM P/N 3634621 specifically designed for use in aluminum engines. Failure to use the engine coolant supplement (sealant) and the approved coolant antifreeze could result in major engine damage. When refilling the cooling system, add three pellets of the engine coolant supplement sealant GM P/N 3634621 to the lower radiator hose.
