GMC Terrain: Cooling System / Checking Coolant

The vehicle must be on a level surface when checking the coolant level.

GMC Terrain. Checking Coolant

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. If coolant is visible but the coolant level mark is not visible, add a 50/50 mixture of clean, drinkable water and DEX-COOL coolant at the coolant surge tank to the top rib on the middle of the tank, but be sure the cooling system is cool before this is done. See Engine Overheating.

The coolant surge tank is located in the engine compartment on the driver side of the vehicle. See Engine Compartment Overview.

    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...

    How to Add Coolant to the Coolant Surge Tank

    Warning Steam and scalding liquids from a hot cooling system are under pressure. Turning the pressure cap, even a little, can cause them to come out at high speed and you could be burned...

    Other information:

    GMC Terrain 2018-2026 Owners Manual: Manual Reclining Seatbacks


    Warning If either seatback is not locked, it could move forward in a sudden stop or crash. That could cause injury to the person sitting there. Always push and pull on the seatbacks to be sure they are locked. To recline a manual seatback: Lift the lever...

    GMC Terrain 2018-2026 Owners Manual: General Information


    Your vehicle is an important investment. This section describes the required maintenance for the vehicle. Follow this schedule to help protect against major repair expenses resulting from neglect or inadequate maintenance. It may also help to maintain the value of the vehicle if it is sold...

    Copyright © 2026 www.gmcterrain2.com