How to flush a heater core in a pontiac grand prix 2002

1. Remove the right instrument panel (I/P) insulator. Refer to Instrument Panel Insulator Panel Replacement - Right Side in Instrument Panel, Gages, and Console.



2. Remove the I/P compartment. Refer to Instrument Panel Compartment Replacement in Instrument Panel, Gages, and Console.
   
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4. Remove the screws that secure the mode actuator (1) to the HVAC module assembly.



5. Remove the mode actuator from the HVAC module assembly.



6. Disconnect the electrical connector from the mode actuator.

Instrument Panel Insulator Panel Replacement - Right Side



Remove 3 fasteners. Rotate the lamp. Remove the lamp from the insulator. Remove the insulator.



Instrument Panel Compartment Replacement



Using the finger opening, remove the access hole cover from the right instrument panel (I/P) compartment



Pull the I/P outboard trim plate rearward in order to release the retainers. Remove the I/P trim plate. Open the I/P compartment



Disengage the compartment door stop using the following procedure:







5.1.





Press the upper door stop (2) toward the center of the vehicle.














5.2.





Rotate the door away from the compartment.








Pull the I/P accessory trim plate rearward slightly for access to the I/P inboard trim plate. Refer to Instrument Panel Accessory Trim Plate Replacement .

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blend door actuator stuck on cold setting .... make sure ur not low on coolant to cause that will always mean no heat

The blend door is probably what is keeping the air from blowing across the heater core and picking up the heat. I hope your manual gives a description and procedure for it.

The blend door actuator and other heater case doors will be either vacuum operated with a few canister diaphragms situated around the heater case, or they may be operated with electric motors. If you pull off the lower sound insulator panels below the dash, you can see the bottom of the heater case, and then find the actuator for the blend door. If vacuum operated, check for vacuum. The vacuum for the heater/AC controls comes from a single line from the engine, through the firewall, and into the back of the control head or to a control module. Then, many vacuum lines branch out from this central point to the canisters- the heater/AC controls will direct vacuum to appropriate actuators, or servos.

The heater core is under the dash. Go to autozone.com and register with them. Look up heater core in repairs. They will give you free instructions on how to remove and install.

blend door actuator failing and sticking on cold setting

No. I don't think an oil change will solve your problem. Neither will a new battery. Likely, that the heater core is blocked up inside. Can try to remove the heater hose and flush it out, when cool. Or, else, the vacuum tube is disconnected from the blend door, or something like that. It's likely that the heater core is blocked up over time with sediment built up in the coolant fluid on a car that old, assuming it's not the blend door problem.

ether the blend door actuator is bad or the climate control module is failing. most likely the blend door actuator. would have to pull most of the under dash out to get to it to replace it. not fun at all.

Manual does not indicate you have a control valve, so problem is likely to be clogging of the core or stuck blend door. How hot are the heater hoses at the firewall? If not really hot, problem is likely clogging of the core. If they are hot, blend door is more likely stuck.
Look under the dash and see if you can see the temperature control actuator moving when you change the temperature setting. I think yours is an electric motor--a little black box attached to the heater box somewhere to the right of center. Let me know if you have questions.

check the temp control switch in the dash

Take off the hoses at the bulkhead/firewall that go to te heater core, use a garden hose and back flush the core by forcing water through the smaller of the 2 hose nipples, if the water runs right through then you have a heater air temp control door actuator problem