GM Service Manual Online
For 1990-2009 cars only

The cooling system in your vehicle is filled with DEX-COOL® engine coolant. This coolant is designed to remain in your vehicle for five years or 100,000 miles (166 000 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 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 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 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.

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 retailer check your cooling system.

Checking Coolant


Object Number: 1222555  Size: A3

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.


Object Number: 1222558  Size: B3

The vehicle must be on a level surface. When your engine is cold, the coolant level should be at the Cold line (surge tank seam). When your engine is warm, the level should be at the Cold line or a little higher.

If the low coolant light comes on and stays on, it means you're low on engine coolant. See Low Coolant Warning Light .

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. See Engine Overheating for instructions on "How to Add Coolant to the Coolant 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.

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