Chevrolet Cobalt Owners Manual: Engine Coolant

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

WARNING:
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.

The coolant surge tank is located in the engine compartment on the driver's side of the vehicle.

See Engine Compartment Overview for more information on location.

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 is not at or above the COLD FILL mark, add a 50/50 mixture of clean, drinkable water and DEX-COOL® coolant at the coolant surge tank, but be sure the cooling system is cool before this is done.

The coolant level should be at the COLD FILL line.

If it is not, you may have a leak in the cooling system.

How to Add Coolant to the Surge Tank

WARNING:
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.

WARNING:
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.

WARNING:
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 coolant is needed, add the proper DEX-COOL® coolant mixture at the coolant surge tank.

1. You can 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. Turn the pressure cap slowly counterclockwise about two or two and one-half turns. If you hear a hiss, wait for that to stop.

This will allow any pressure still left to be vented out the discharge hose.

2. Then keep turning the pressure cap slowly,
and remove it.

3. Fill the coolant surge tank with the proper mixture, to the COLD FILL line on the tank. Wait about five minutes, then check to see if the level is below the COLD FILL line. If the level is below the line, add additional coolant to bring the level up to the line. Repeat this procedure until the level remains constant at the COLD FILL line for at least five minutes.

4. With the coolant surge tank pressure 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 fan.

By this time, the coolant level inside the coolant surge tank may be lower. If the level is lower than the COLD FILL line, add more of the proper mixture to the coolant surge tank until the level reaches the COLD FILL line.

5. Then replace the pressure cap. Be sure the pressure cap is hand-tight and fully seated.

See your dealer/retailer, if necessary.