99 Grand Am GT overheating

[adita]

My 99 Grand Am has recently begun overheating. I replaced the thermostat and the intake manifold gaskets but it still overheats. Once the car overheats it cools down quickly and there is no heat only cold air from the vents. Please help!!!

[pcv]

Make sure there are no air bubbles is the system. Run the car, crack the bleeder screw above the waterpump area until fluid comes out of it. Verify radiator fan operation when hot and you are in business.
Good Luck.

[Slade901]

Could be your radiator cap is in need of replacement.
If the radiator cap has weaken it will open the radiator cap to allow the coolant overflow to the coolant reservoir.
The radiator cap has a PSI rating which will only open when the pressure of the cooling system reaches the PSI rating of the radiator cap and then it will allow the excess coolant fluid to the coolant reservoir. If the radiator cap is failing it will allow the coolant to escape to the coolant reservoir even though the cooling system pressure has not reached the rated PSI rating of the radiator cap.
Failing radiator cap lowers the max boiling point of the cooling system and so it overheats quickly.
Old cooling system also begins to lower its boiling point temperature.
New engine that uses the orange cooling system has 5 year flush maintenance requirements and while those that uses the green coolant has 2 year flush maintenance requirements.

[GMMerlin]

Originally Posted by adita

My 99 Grand Am has recently begun overheating. I replaced the thermostat and the intake manifold gaskets but it still overheats. Once the car overheats it cools down quickly and there is no heat only cold air from the vents. Please help!!!

If the engine is overheating and there is no hot air from your heater core, then 1 of 2 things is going on.
Did this start after you had done the intake gaskets? If so, then most likely you have an air pocket in the cooling system.
Remove the radiator cap (surge tank cap) and loosen the bleeder screws. Fill the cooling system until you get coolant running out the bleeders. Close the bleeders and start the engine and allow it to get to operating temp (if the engine begins to overheat or the temp gage starts reading over 200 and the upper radiator hose is cold, turn off the key and let the engine sit for a while...this will help purge the air pocket.

If this problem has been occuring for some time, you may have overheated the engine to the point of blowing the head gaskets.

[intillekt]

ok, i have the same exact problem with my grand am, but the dealer swears that it is supposed to run @ 220-230 degrees?? is this true???