Replacement directions for Heater core

Hi,

The heater core is located on the inside of the vehicle under the dash. It's a little bit of a job but if you follow the directions, you can do it.

First, here is a link that shows how it's done in general. Use this as a guide.

https://www.2carpros.com/articles/replace-heater-core

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Here are directions specific to your vehicle. The two attached pics are the actual directions and an exploded view of the heater unit.

2008 Chevrolet Impala V6-3.5L
Heater Core Replacement
Vehicle Heating and Air Conditioning Heater Core Service and Repair Removal and Replacement Heater Core Replacement
HEATER CORE REPLACEMENT
Heater Core Replacement

pic 1

pic 2

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I hope this helps. Let me know if you have other questions.

Take care and God Bless,

Joe

Hello, I'm Danny.

Here is the information you requested. Here is a tutorial to get you started on how to replace a heater core:

https://www.2carpros.com/articles/replace-heater-core

I've attached picture steps below on how to remove and replace the heater core on your car. Hope this helps and thanks for using 2CarPros.

REMOVAL:
Disconnect the negative battery cable.
If equipped with a 3.1L engine, remove the air cleaner and duct assembly.
If equipped with a 3.8L engine, remove the fuel injector sight shield by performing the following procedures:
Clean the area around the oil filler cap/tube assembly location.
Rotate the oil filler cap/tube assembly counterclockwise from the valve cover.
Lift the fuel injector sight shield up at the front and slide it from the rear engine bracket.
Reinstall the oil filler cap/tube assembly in the valve cover.

CAUTION
Before draining the cooling system, allow the engine to cool to relieve the systems internal pressure and to avoid scalding coolant.

Drain the cooling system by performing the following procedure:
Raise and safely support the front of the vehicle.
Remove and clean the coolant recovery tank.
Place a 2 gallon pan under the radiator to catch the coolant.
At the bottom of the radiator, open the drain valve and drain the coolant to a level lower than the heater core.
Remove the radiator cap and open the air bleed screw (2-3 turns) located on top of the thermostat housing.
After sufficient coolant has been drained from the system, close the drain valve.

CAUTION
Engine coolant is a hazardous waste; it should be stored for reuse or submitted for recycling. NEVER dispose of it by dumping it into the environment.

Disconnect and plug the heater hoses at the heater core.
If equipped, remove the lower center console by removing or disconnecting the following:

Cigarette lighter
Automatic transaxle shift handle
Upper console trim plate from the front floor console by unsnapping it
Electrical connectors from the upper console trim plate and remove the trim plate
CD storage compartment from the front floor console by unsnapping it
Raise the front floor console armrest and remove the compartment mat
Console-to-chassis bolts and screws
Electrical connectors from the console and remove the console from the vehicle

Remove the lower instrument panel lower compartment by removing or disconnecting the following:

Lower right instrument panel insulator
Compartment-to-panel bolts and screws, from under the instrument panel compartment
Instrument panel compartment door screws and the door
Instrument panel compartment screws and plastic clips; then slide the compartment from the instrument panel
Electrical connector from the compartment
Ashtray and bracket, if necessary
Lower heater duct
Heater core cover and discard the cover seals Heater core mounting clip and bracket
Heater core

INSTALLATION:
Install and connect the following:

Heater core in the vehicle
Heater core mounting clip and bracket
New seals on the heater core cover
Heater core cover and torque the bolts to 13 inch lbs. (1.5 Nm)
Lower heater duct, if removed
Ashtray and bracket, if removed

Install the lower instrument panel lower by installing or connecting the following:

Electrical connector to the compartment
Slide the compartment into the instrument panel; then, secure it with screws and plastic clips Instrument panel compartment door and screws Compartment-to-panel bolts and screws, located under the instrument panel compartment
Lower right instrument panel insulator

If equipped, install the lower center console install or connect the following:

Console in the vehicle and connect the electrical connectors
Console-to-chassis bolts and screws, tighten in sequence beginning at the front right and continue in a clockwise order to 106 inch lbs. (12 Nm) Armrest compartment mat and lower the front floor console armrest C/D storage compartment into the front floor console
Electrical connectors to the upper console trim plate and snap the trim plate onto the console
Automatic transaxle shift handle and the cigarette lighter
Heater hoses to the heater core and secure with the clamps

Refill the cooling system by performing the following procedure:
Close the radiator drain valve.
If the air bleed screws (located at the top of the thermostat housing) is closed, open it by turning it 2-3 turns.
Slowly add coolant until it reaches the radiator neck.
Wait for 2 minutes and recheck the coolant level; then, add more coolant if necessary.
Fill the coolant reservoir to the COLD mark.
Close the air bleed screw.
WARNING
Do not over-tighten the air bleed screw for it is made of brass.

Install the radiator cap and make sure that the arrows align with the overflow tube.

If equipped with a 3.8L engine, install the fuel injector sight shield by performing the following procedures:
Remove the oil filler cap/tube assembly from the valve cover.
Slide the fuel injector sight shield into the rear engine bracket and lower it into place.
Reinstall the oil filler cap/tube assembly in the valve cover. Twist it clockwise to lock the detent on the tube into the notch in the valve cover.

If equipped with a 3.1L engine, install the air cleaner and duct assembly.
Connect the negative battery cable.

Thanks for using 2CarPros. Com!

The above procedures is the best way and recommended way of removing and replacing your vehicle's heater core. You will need to remove the instrument panel lower trim panel and remove the retaining screw and bolts to remove duct.

Hey BRIAN,

Doing a heater core is a big job but you can tackle it if you just stick to it. Here are some instructions and a diagram or two to help you through the job.

Remove the fuel injector sight shield.

Drain the cooling system. Refer to Draining and Filling Cooling System in Cooling System.
Use J 38185 in order to position aside the heater hose inlet and outlet clamps at the heater core.
Disconnect the inlet and outlet heater hose from the heater core.
Remove the RH Instrument Panel Closeout/Insulator panel.
Remove the LH Instrument Panel Closeout/Insulator panel
Remove the floor carpet.
Remove the rear floor air outlet duct from the holes in the floor reinforcement.
Disconnect the rear floor air outlet duct from the heater air outlet cover.
Remove the rear floor air outlet duct.
Remove the heater air outlet cover screws (2).
Remove the heater air outlet cover heat stakes (1) with a small chisel.
Remove the heater air outlet cover from the HVAC module assembly.
Remove the heater core cover screws (2).
Remove the heater core cover heat stakes (1) with a small chisel.
Remove the heater core cover from the HVAC module assembly.
Remove the heater core from the HVAC module assembly.
Remove the heater core foam seal (1) from the HVAC module assembly.

Please let us know happens so it will help others. Check out the diagram (Below)

Best, Ken

That description sounds like there is air in the system or you have a failing head gasket that is putting combustion gases into the system and causing pockets of air that way. It is also possible the cap is faulty but that usually will show as low coolant.
Are you removing the bleed screws on the engine while filling with coolant?

There should be one on each end of the engine. One on top of the upper radiator fitting over the thermostat housing, the other in above the water pump. 7MM that looks like a pipe plug.
Another option is to see if your local part store has a vacu-fill system you can rent. With that you drain the coolant down, then apply enough vacuum to pull out all the air, then it sucks the coolant into the system and you have no air pockets.

That should take care of the problem. The 3.1 and 3.4 both have a bad habit of holding air in the block. Once you get them "burped" they settle down. It is why I have the vacuum unit it pulls all the air out you do not need play with the bleeders. Many engine these days have bleeder valves.
Keep us informed please.

Good morning

Just to add what Steve has posted, do not open the bleeders with the engine running. It will draw air into the system. Only open the bleeders while filling.

Roy

Make sure it is antifreeze and not water if water check to make sure drain hose is going through firewall an drubber above cabin filter is draining correctly or not partially off. See pics for instructions.