GM Service Manual Online
For 1990-2009 cars only

When you decide it is safe to lift the hood, this is what you see:

V6 Engine


Object Number: 1970945  Size: G4
  1. Coolant Reservoir and Dipstick

  2. Radiator Pressure Cap

V8 Engine


Object Number: 1970946  Size: G4
  1. Coolant Reservoir and Dipstick

  2. Radiator Pressure Cap

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.

The coolant level should be at or above the top mark on the coolant reservoir dipstick. If it is not, you may have a leak at the radiator pressure cap or in the radiator hoses, heater hoses, radiator, water pump, or somewhere else in the cooling system.

Caution: Heater and radiator hoses, and other engine parts, can be very hot. Do not touch them. If you do, you can be burned.

Do not run the engine if there is a leak. If you run the engine, it could lose all coolant. That could cause an engine fire, and you could be burned. Get any leak fixed before you drive the vehicle.

If there seems to be no leak, with the engine on, check to see if the electric engine cooling fans are running. If the engine is overheating, both fans should be running. If they are not, your vehicle needs service.

Notice: Engine damage from running the engine without coolant is not covered by the warranty.

Notice: Using coolant other than DEX-COOL® can cause premature engine, heater core, or radiator corrosion. In addition, the engine coolant could 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 the vehicle.

How to Add Coolant to the Cooling System

Notice: This vehicle has a specific coolant fill procedure. Failure to follow this procedure could cause the engine to overheat and be severely damaged.

If no coolant is visible in the coolant reservoir, add coolant as follows:

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: In cold weather, water can freeze and crack the engine, radiator, heater core and other parts. Use the recommended coolant and the proper coolant mixture.

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.

  1. Check the engine coolant reservoir (A) level and, if required, top with coolant. See Engine Coolant.

  2. Object Number: 2028807  Size: G1
  3. Locate the radiator pressure cap (B).
  4. 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.

  5. Cover the cap with a thick cloth and turn it slowly counterclockwise and remove.
  6. If there is no coolant or the level is low, slowly fill the system through the radiator pressure cap opening with a 50/50 mixture of clean, drinkable water and a DEX-COOL® coolant until full. Wait 30 seconds for coolant to settle and top off if the level drops.
  7. Do not spill coolant on the accessory drive belts.

    If a spill occurs, rinse the belt with fresh water.

  8. Start the engine.
  9. With the engine idling, top off the coolant through the radiator pressure cap opening until full.
  10. Wait 30 seconds for the coolant to settle and top off, if the level drops.

  11. Once the system is full, put the radiator pressure cap back on by turning clockwise.
  12. Turn off the ignition.
  13. Check the coolant level in the reservoir and fill it until the level is at the top of the dipstick.