Heat problem

I have a 2008 equinox 3.4 L. The problem is I have no heat when a car comes to standstill from driving the heat works fine I change the thermostat and I change the reservoir Or pressure cup all I can think of now is that my air-conditioning will come on now it all. I did have something come up on my dash saying car overheat but now it's gone again but the engine is not hot at all .

Number one cause of "no heat" complaint is lack of coolant- check the radiator as well as the recovery tank-

if full, then you must have an air pocket- to fix that, look for bleeders at thermostat housing to bleed off air--

if all that is ok- check for hot or cold heater hoses- if both hot, then air door issue inside, if both cold, then there is no flow- due to air or plugged up, or lack of coolant.

It sounds to me like the cooling system has air in it that needs to be bled out. The bleeder screw is located on top of the water pump housing on the 3400. You may need to remove the engine cover to see it.

It is normal for the A/C to be disabled when the overheat/hot engine message is displayed. It is also disabled when when ambient air temps drop below 40°F.

And when there is air in the system, it's usually because of a leak....

ok still have same issue , there no leak, did oil change it was all good, had coolant changed, new thermostat and new cap, I have bleed it out , but one thing I noticed is the recovery tank looks almost empty but if I remove the cap it fill up and sounds like a jug empting. please help lol
thanks tom

ok still have same issue , there no leak, did oil change it was all good, had coolant changed, new thermostat and new cap, I have bleed it out , but one thing I noticed is the recovery tank looks almost empty but if I remove the cap it fill up and sounds like a jug empting. please help lol
thanks tom

The cooling system isn't full. The reservoir should be filled up to or just above the seam when cold. When you open the cap while the engine is warm, you are releasing the pressure which is causing the coolant to boil.

Filling Procedure

Important: When the radiator is drained, a minimum of 5 liters (5.28 qts) of coolant is typically drained from the cooling system. During the fill procedure, a minimum of 5 liters (5.28 qts) of coolant should be added to the cooling system before the vehicle is returned to the customer.

1. Close the drain valve on the left radiator end tank.
2. Install the engine block drain plug, if removed.
3. Open the air bleed screw on the water pump tower.

Caution! All entrapped air must be purged from the powertrain cooling system before the final coolant level can be determined. Proper coolant level is critical to avoid engine damage.

Important: The vehicle must be level when filling the cooling system.

4. Slowly add a mixture of 50/50 DEX-COOL antifreeze and clean water to the surge tank. Refer to Approximate Fluid Capacities for cooling system capacity.
...4.1. As the system begins to fill, watch for coolant at the water pump tower.
...4.2. As coolant begins to seep from the air bleed, close the air bleed screw.
...4.3. Once the bleed screw is closed, continue to add coolant until a minimum of 5 liters (5.28 qts) is added to the cooling system. Start the engine and run at idle to add the remaining coolant.
5. Install the surge tank cap.
6. Run the engine and cycle the vehicle from idle to 3,000 RPM in 30 second intervals until the engine cooling fans come ON.
7. Return the engine to idle, idle for 30 seconds then turn the engine OFF.
8. Allow the vehicle to cool.
9. Add coolant to the surge tank until the level is approximately 25 mm (1 in) above the top of the Cold Fill Range at the surge tank seam.
10. Install the surge tank cap.

Ya I have done that, I almost lol

I am lost I ment to say lol