Grand Prix V6-191 3.1L VIN M SFI (1998)
Coolant: Service and Repair
Draining and Filling the Cooling System
Ethylene glycol/water fill ratios have been established to ensure a minimum of 50 percent ethylene glycol in the coolant flush and drain procedure, and
ensuring that all engine block drains and air bleeds were utilized.
The cooling system capacity for the 3100 engine is 10.9 liters (11.6 quarts); for the 3800 engine it is 10.1 liters (10.7 quarts). The coolant recovery
reservoir capacity is 0.65 liters (0.68 quarts) to the COLD mark on the reservoir. The quantities listed in the filling procedure include the additional
quantity to displace the air remaining in the coolant system after a static refill.
Using the correct fill ratio and the following procedures will ensure a minimum concentration of 50 percent ethylene glycol in the coolant system and
simplify the customer fill task. Refer to Specifications for static fill radiator capacities. Every five years or 240,000 km, (150,000 miles), whichever
occurs first, the cooling system should be drained and filled using the following recommended procedures.
CAUTION: As long as there is pressure in the cooling system, the temperature can be considerably higher than the boiling temperature of the
solution in the radiator without causing the solution to boil. Removal of the pressure cap while the engine is hot and pressure is high will cause the
solution to boil instantaneously - possibly with explosive force - spewing the solution over the engine, fenders and the person removing the cap.
NOTICE: When adding coolant, it is important that you use GM Goodwrench DEX-COOL or HAVOLINE DEX-COOL coolant. If Coolant other
than DEX-COOL or HAVOLINE DEX-COOL is added to the system the engine coolant will require change sooner - at 50,000 km (30,000 miles) or
24 months.
DRAINING PROCEDURE
IMPORTANT: This procedure significantly increases the amount of used coolant and diluted hazardous waste.
1. Park the vehicle on a level surface.
2. Remove and clean coolant recovery reservoir.
3. Remove the radiator cap when the engine is cool:
3.1. Slowly rotating the cap counterclockwise to detent. Do not press down while rotating pressure cap.
3.2. Wait until any residual pressure (indicated by a hissing sound) is relieved.
3.3. After all hissing stops, continue to rotate counterclockwise until the cap is removed.
IMPORTANT: Recover coolant and store in a used coolant holding tank and submit the used coolant for recycling on a regular basis. This
procedure significantly increases the amount of used coolant and diluted hazardous waste.
4. Place drain pan under vehicle to collect all drained coolant.
5. Open the radiator drain valve located at the bottom of the radiator tank. For procedures requiring the cooling system to be partially drained,
opening the radiator drain valve should provide sufficient draining and no further actions should be necessary.
6. Open the air bleed vent on the thermostat housing.
7. For the 3100 engine, remove both engine block drains. The front engine block drain is located between the starter and the engine oil filter. The
rear engine block drain is located by the engine crank sensor.
