GM Service Manual Online
For 1990-2009 cars only

Pickup Models

The cooling system in your vehicle is filled with DEX-COOL® engine coolant. This coolant is designed to remain in your vehicle for 5 years or 150,000 miles (240 000 km), whichever occurs first, if you add only DEX-COOL® extended life coolant.

The following explains your cooling system and how to add coolant when it is low. If you have a problem with engine overheating, see Engine Overheating .

A 50/50 mixture of clean, drinkable water and DEX-COOL® coolant will:

    • Give freezing protection down to -34°F (-37°C)
    • Give boiling protection up to 265°F (129°C)
    • Protect against rust and corrosion
    • Help keep the proper engine temperature
    • Let the warning lights and gages work as they should

Notice: Using coolant other than DEX-COOL® can cause premature engine, heater core, or radiator corrosion. In addition, the engine coolant may require changing sooner, at the first maintenance service after each 30,000 miles (50 000 km) or 24 months, whichever occurs first. Any repairs would not be covered by the vehicle warranty. Always use DEX-COOL® (silicate-free) coolant in the vehicle.

What to Use

Use a mixture of one-half clean, drinkable water and one-half DEX-COOL® coolant which won't damage aluminum parts. If you use this coolant mixture, you don't need to add anything else.

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 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.

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.

If you have to add coolant more than four times a year, have your dealer check your cooling system.

Notice: If you use extra inhibitors and/or additives in your vehicle's cooling system, you could damage your vehicle. 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


Object Number: 1657487  Size: B3

The coolant surge tank is located in the engine compartment on the passenger side of the vehicle. See Engine Compartment Overview for more information on its location.

Caution: Turning the surge tank pressure cap when the engine and radiator are hot can allow steam and scalding liquids to blow out and burn you badly. Never turn the surge tank pressure cap -- even a little -- when the engine and radiator are hot.

The vehicle must be on a level surface. When your engine is cold, the coolant level should be at the FULL COLD mark.

If your vehicle has a low coolant sensor and the COOLANT LEVEL LOW ADD COOLANT Driver Information Center (DIC) message comes on, and stays on, it means the vehicle is low on engine coolant. See COOLANT LEVEL LOW ADD COOLANT under "DIC Warnings and Messages" in the Index of your vehicle's owner manual.

Adding Coolant

If you need more coolant, add the proper DEX-COOL® coolant mixture at the surge tank , but only when the engine is cool. If the surge tank is empty, see Engine Overheating .

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.

When replacing the pressure cap, make sure it is hand-tight.

Van Models

The cooling system in your vehicle is filled with DEX-COOL® engine coolant. This coolant is designed to remain in your vehicle for 5 years or 150,000 miles (240 000 km), whichever occurs first, if you add only DEX-COOL® extended life coolant.

The following explains your cooling system and how to add coolant when it is low. If you have a problem with engine overheating, see Engine Overheating .

A 50/50 mixture of clean, drinkable water and DEX-COOL® coolant will:

    • Give freezing protection down to -34°F (-37°C).
    • Give boiling protection up to 265°F (129°C).
    • Protect against rust and corrosion.
    • Help keep the proper engine temperature.
    • Let the warning lights and gages work as they should.

Notice: Using coolant other than DEX-COOL may cause premature engine, heater core, radiator and fuel operated heater (FOH) corrosion. In addition, the engine coolant may require changing sooner, at 30,000 miles (50 000 km) or 24 months, whichever occurs first. Any repairs would not be covered by your warranty. Always use DEX-COOL (silicate-free) coolant in your vehicle.

What to Use

Use a mixture of one-half clean, drinkable water and one-half DEX-COOL® coolant which won't damage aluminum parts. If you use this coolant mixture, you don't need to add anything else.

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 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.

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.

If you have to add coolant more than four times a year, have your dealer check your cooling system.

Notice: If you use extra inhibitors and/or additives in your vehicle's cooling system, you could damage your vehicle. 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


Object Number: 1643081  Size: A3

The surge tank is located near the center of the engine compartment. See Engine Compartment Overview for more information on its location.

Caution: Turning the surge tank pressure cap when the engine and radiator are hot can allow steam and scalding liquids to blow out and burn you badly. Never turn the surge tank pressure cap -- even a little -- when the engine and radiator are hot.

The vehicle must be on a level surface. When your engine is cold, the coolant level should be at the COLD FILL mark.

Adding Coolant

If you need more coolant, add the proper DEX-COOL® coolant mixture at the surge tank , but be careful not to spill it.

Caution: You can be burned if you spill coolant on hot components in the engine compartment. Coolant contains ethylene glycol, and it will burn if the engine parts are hot enough. Do not spill coolant on a hot engine or components in the engine compartment.

When replacing the pressure cap, make sure it is hand-tight.

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 coolant surge tank is located in the engine compartment on the passenger side of the vehicle. See Engine Compartment Overview for more information on location.

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. 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 surge tank, but be sure the cooling system is cool before this is done.


Object Number: 1657487  Size: B3

The coolant level should be at or above the FULL COLD mark. If it is not, you may have a leak in the cooling system.

If the vehicle has a low coolant sensor and the LOW COOLANT LEVEL message comes on and stays on, it means you are low on engine coolant. See "LOW COOLANT LEVEL" under DIC Warnings and Messages.

How to Add Coolant to the Coolant Surge Tank for Gasoline Engines

If the vehicle has a diesel engine, see "Cooling System" in the DURAMAX® Diesel Supplement for the proper coolant fill procedure.

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 coolant surge tank pressure cap -- even a little -- they can come out at high speed. Never turn the cap when the cooling system, including the coolant surge tank pressure cap, is hot. Wait for the cooling system and coolant 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:


    Object Number: 809006  Size: A2

    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.

  1. Turn the pressure cap slowly counterclockwise about one full turn. If you hear a hiss, wait for that to stop. A hiss means there is still some pressure left.
  2. Keep turning the pressure cap slowly, and remove it.

  3. Object Number: 1690640  Size: B3
  4. Fill the coolant surge tank with the proper mixture to the FULL COLD mark.
  5. With the coolant surge tank pressure cap off, start the engine and let it run until the engine coolant temperature gage indicates approximately 195°F (90°C).
  6. 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.

  7. Replace the pressure cap. Be sure the pressure cap is hand-tight and fully seated.
  8. Verify coolant level after engine is shut off and the coolant is cold. If necessary, repeat coolant fill procedure Steps 1 through 6.

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.