GMC Terrain: Cooling System / What to Use

Warning

Plain water, or other liquids such as alcohol, can boil before the proper coolant mixture will. With plain water or the wrong mixture, the engine could get too hot but there would not be an overheat warning. The engine could catch fire and you or others could be burned.

Use a 50/50 mixture of clean, drinkable water and DEX-COOL coolant. If using this mixture, nothing else needs to be added. This mixture:

  • Gives freezing protection down to −37 °C (−34 °F), outside temperature.
  • Gives boiling protection up to 129 °C (265 °F), engine temperature.
  • Protects against rust and corrosion.
  • Will not damage aluminum parts.
  • Helps keep the proper engine temperature.

Caution

Do not use anything other than a mix of DEX-COOL coolant that meets GM Standard GMW3420 and clean, drinkable water. Anything else can cause damage to the engine cooling system and the vehicle, which would not be covered by the vehicle warranty.

Never dispose of engine coolant by putting it in the trash, pouring it on the ground, or pouring into sewers, streams, or bodies of water. Have the coolant changed by an authorized service center, familiar with legal requirements regarding used coolant disposal. This will help protect the environment and your health.

    Engine Coolant

    The engine cooling system in the vehicle is filled with DEX-COOL engine coolant mixture. This coolant needs to be checked and changed at appropriate levels...

    Checking Coolant

    The vehicle must be on a level surface when checking the coolant level. Check to see if coolant is visible in the coolant surge tank. If the coolant inside the coolant surge tank is boiling, do not do anything else until it cools down...

    Other information:

    GMC Terrain 2018-2025 Owners Manual: Tire Terminology and Definitions


    Air Pressure : The amount of air inside the tire pressing outward on each square inch of the tire. Air pressure is expressed in kPa (kilopascal) or psi (pounds per square inch). Accessory Weight : The combined weight of optional accessories. Some examples of optional accessories are automatic transmission, power windows, power seats, and air conditioning...

    GMC Terrain 2018-2025 Owners Manual: Filling the DEF Tank


    Caution Use only DEF that is GM approved, or fluid containing the API certified or ISO 22241 label. The use of other fluids could damage the system, requiring costly repairs that will not be covered by the vehicle warranty. Caution Do not mix fuel with DEF, and do not put DEF in the fuel tank...

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