The cooling system in the vehicle is filled with DEX-COOL® engine coolant. This coolant is designed to remain in the vehicle for five years or 150,000 miles (240 000 km), whichever occurs first.
The following explains the cooling system and how to check and add coolant when it is low. If there is a problem with engine overheating, see Engine Overheating.
What to Use
Caution: Adding only plain water to the cooling system can be dangerous. Plain water, or some other liquid such as alcohol, can boil before the proper coolant mixture will. The vehicle's coolant warning system is set for the proper coolant mixture. With plain water or the wrong mixture, the engine could get too hot but you would not get the 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.
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 -34°F (-37°C), outside temperature. |
| • | Gives boiling protection up to 265°F (129°C), engine temperature. |
| • | Protects against rust and corrosion. |
| • | Will not damage aluminum parts. |
| • | Helps keep the proper engine temperature. |
Notice: If an improper coolant mixture is used, the engine could overheat and be badly damaged. The repair cost would not be covered by the vehicle warranty. Too much water in the mixture can freeze and crack the engine, radiator, heater core, and other parts.
Notice: If extra inhibitors and/or additives are used in the vehicle's cooling system, the vehicle could be damaged. Use only the proper mixture of the engine coolant listed in this manual for the cooling system. See Recommended Fluids and Lubricants for more information.
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 recovery tank. If the coolant inside the coolant recovery tank is boiling, do not do anything else until it cools down. If coolant is visible but the coolant level is not at or above the FULL COLD mark, add a 50/50 mixture of clean, drinkable water and DEX-COOL® coolant at the coolant recovery tank, but be sure the cooling system is cool before this is done. See Engine Coolant for more information.
How to Add Coolant to the Surge Tank
Caution: You can be burned if you spill coolant on hot engine parts. Coolant contains ethylene glycol and it will burn if the engine parts are hot enough. Do not spill coolant on a hot engine.
Notice: This vehicle has a specific coolant fill procedure. Failure to follow this procedure could cause the engine to overheat and be severely damaged.
Caution: An electric engine cooling fan under the hood can start up even when the engine is not running and can cause injury. Keep hands, clothing, and tools away from any underhood electric fan.
Caution: Steam and scalding liquids from a hot cooling system can blow out and burn you badly. They are under pressure, and if you turn the surge tank pressure cap -- even a little -- they can come out at high speed. Never turn the cap when the cooling system, including the surge tank pressure cap, is hot. Wait for the cooling system and surge tank pressure cap to cool if you ever have to turn the pressure cap.
If no coolant is visible in the surge tank, add coolant as follows:
- Turn the pressure cap slowly counterclockwise. If you hear a hiss, wait for that to stop. A hiss means there is still some pressure left.
- Keep turning the cap and remove it.
- With the coolant surge tank cap off, start the engine and let it run until you can feel the upper radiator hose getting hot. Watch out for the engine cooling fans.
- Replace the cap. Be sure the cap is hand-tight and fully seated.
Remove the coolant surge tank pressure cap when the cooling system, including the coolant surge tank pressure cap and upper radiator hose, is no longer hot.
Fill the coolant surge tank with the proper mixture to the FULL COLD mark on the side of the coolant surge tank.
4.6L L37 Engine shown, 4.6L LD8 Engine similar
By this time, the coolant level inside the coolant surge tank may be lower. If the level is lower, add more of the proper mixture to the coolant surge tank until the level reaches the FULL COLD mark on the side of the coolant surge tank.
Notice: If the pressure cap is not tightly installed, coolant loss and possible engine damage may occur. Be sure the cap is properly and tightly secured.
If coolant is needed, add the proper DEX-COOL® coolant mixture at the coolant recovery tank.
