The cooling fan come's on at 212 degree's here is a description of the fan operation.I also posted the draining and refilling of the coolant along with bleeding the air out of it. Let me know what happens after your done with thermostat replacement and the bleeding of the air in the coolant.
WARNING: An electric fan under the hood can start up even when the engine is not running and can injure you. Keep hands, clothing and tools away from any underhood electric fan.
All vehicles use two 360 mm (14.2 inch) fans to aid air flow through the radiator/condenser. Each fan is driven by an electric motor and is attached to the radiator. Electrical motor size varies with engine option. The fan motors are activated by a coolant temperature switch. A transducer can also activate the circuit, depending upon A/C request or A/C compressor head pressure to the condenser.
NOTE: This procedure significantly increases the amount of used coolant and diluted hazardous waste.
Park the vehicle on a level surface.
Remove and clean coolant recovery reservoir.
Remove the radiator cap when the engine is cool by:
Slowly rotating the cap counterclockwise to detent. Do not press down while rotating pressure cap.
Wait until any residual pressure (indicated by a hissing sound) is relieved.
After all hissing stops, continue to rotate counterclockwise until the cap is removed.
NOTE: 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.
Place drain pan under vehicle to collect all drained coolant.
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.
Open the air bleed vent(s): Open the air bleed vents on the thermostat housing and above water pump. The air bleed vents should be opened two to three turns.
Remove the engine block drains: 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 in the same area in the center of the block.
Disconnect inlet hose to engine oil cooler (if equipped).
Allow the coolant to drain completely.
WARNING: Dispose of used coolant in a proper fashion, i.E, in a used coolant holding tank. NEVER POUR USED COOLANT DOWN THE DRAIN! Ethylene glycol antifreeze is a very toxic chemical; disposing of it into the sewer system or ground water is both illegal and ecologically unsound!
Close the radiator drain valve. Reinstall all engine block drains.
Install the coolant recovery reservoir. Flush the reservoir with clean water, drain and reinstall.
Slowly fill the cooling system through the radiator neck using the following procedure:
If the coolant system has been flushed, first add 100 percent ethylene glycol in the amount listed for the appropriate engine application. Then slowly add clean water to the system until the level of the coolant mixture has reached the base-of the radiator neck. Wait for two minutes and recheck the level of the coolant mixture, add clean water if necessary to restore the coolant mixture level to the base of the radiator neck.
When refilling the engine cooling system, add three engine coolant supplement sealant pellets, GM P/N 3634621 or equivalent, and GM approved new Ethylene Glycol Coolant DEX-COOL GM P/N 9985809.
If the cooling system is being refilled ONLY (no flush), a 50 percent ethylene glycol and 50 percent clean water mixture should be used to fill the system. Fill the system until the level of the 50/50 mixture has reached the base of the radiator neck. Wait two minutes and recheck the level of the coolant mixture, add a 50/50 ethylene glycol/water mixture as necessary to restore the coolant mixture level to the base of the radiator neck.
Install the radiator cap making certain the arrows line up with the overflow tube.
Close all air bleeds. DO NOT over torque the air bleed valve. The air bleed valve is made out of brass.
Fill the coolant reservoir with a 50 percent ethylene glycol and a 50 percent clean water coolant mixture. The proper amount of this mixture to be installed into the coolant reservoir is listed below:
Add 0.65 liters (0.68 quarts) of a 50/50 mixture of ethylene glycol and clean water to the coolant recovery reservoir.
CAUTION: The low coolant indicator lamp may come on after this procedure. After operating the vehicle so that the engine heats up and cools down three times. If at any time the "TEMP" warning indicator comes on, immediate action is required.
Monday, April 4th, 2011 AT 7:39 PM