REMOVE HEATER CORE 2007 CTS - 2007 Cadillac CTS-V Sedan

Question edited for clarity.
Question moved to model category.

It is a HUGE job, as the dash has to be removed.

https://www.google.com/search?q=2007+Cadillac+CTS.+How+to+remove+the+heater+core

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This is caused by a defective air temperature control blend door actuator motor or a jammed blend door or in most cases both..

2008 Pontiac G6 Heater Core Removal Very Confident My Heater Core

Not from what I am reading. Here is the procedure from the AutoZone repair guide.....

2.8L & 3.6L Engines

1. Before servicing the vehicle, refer to the Precautions Section.
2. Drain the cooling system.
3. Disconnect the heater hoses from the heater core.
4. Remove the thermostat housing bolts.
5. Remove the thermostat housing with the heater pipes, hoses and bolts.
6. Carefully clean the sealing surfaces with a plastic gasket scraper.
7. Remove the thermostat.

To install:

1. Assemble the heater pipes and hoses to the thermostat housing.
2. Install a new gasket to the thermostat housing.
3. Install the thermostat.
4. Install the thermostat housing bolts to the thermostat housing. Partially install the thermostat housing bolts in order to retain the gasket.
5. Install the thermostat housing with the heater pipes, heater hoses, gasket and bolts.
6. Install the thermostat housing bolts and tighten to 15 ft. lbs. (20 Nm).
7. Connect the heater hoses to the heater core.
8. Fill the cooling system.

THIS IS A VERY INVOLVED JOB. THE HEATER CORE IS IN THE EVAPORATOR CASE INSIDE THE DASH ON THE PASSENGER SIDE. TO ACCESS THIS CORE YOU MUST REMOVE THE GLOVEBOX AND ITS. LINER. REMOVE THE PASSENGER AIRBAG AND DISMANTLE THE EVAPORATOR HOUSING. REMOVE THE HEATER HOSES FROM THE FIREWALL UNDER THE HOOD AND THE BLOWER MOTOR.

Have someone else do it ... seriously ... some you replace through the engine compartment some from under the dash. Not sure about a Cadillac. Do a Google search on "How to replace a 2005 Cadillac heater core".

How to change a fuel filter on a 2003 Cadillac CTS - YouTube

? 11:01
https://www.youtube.com/watch?v=SRI7SPzVzvk
Jun 2, 2014 - Uploaded by 2LateIWon
How to change a fuel filter on a 2003 Cadillac CTS. ... Lately... my 2007 cadillac CTS (just hit 100,000 miles) tends to shake for may a second if ...

Hello raiderjoel,

This is a big job, it's 6.5 -7.0 hours. The heater core is right of center. If you open the hood and look at the right side of the engine compartment you can the heater hoses going into the firewall. the heater core is on the inside of the car rust behind where the hoses go thorugh.

Regards,
netvan

If it is necessary to remove the heater assembly, the cooling system must be drained before removing the heater core.
When a heater core leaks, a new heater core is installed or the old one repaired.
Heater Housing

• The heater housing is usually under the dash and must be removed to gain access to the heater core.
• Procedures for replacing the heater core vary with the year, make, and model of car. It threfore necessary to consult the manufacturer's repair manuals for the proper procedure for replacement.

The heater housing is disassembled to get to the heater core. Heater Core

• Remove the access panels(s) or the split heater/air conditioning case to gain acess to the heater core.
• Remove the heater coolant hoses.
• Remove the cable and/or vacuum control lines (if equipped).
• Remove the heater core securing brackets and/or clamps.
• Lift the core from the case. Do not use force. Take care not to damage the fins of the heater core when removing.
• To reinstall the heater core, reverse the removal steps.

When the heater core leaks and must be repaired or replaced, it is a very difficult and time-consuming job primarily because of the core's location deep within the firewall of the car. For this reason always leak test a replacement heater core before installation.

There are a couple of possibilities.
1. The heater core may be plugging up. Dirty coolant and lack of coolant services can contribute to this. Backflushing the heater more resolve the issue. If it does have the cooling system flushed to remove the rest of the contaminates from the cooling system.
2. The coolant level may be low. The heater core is usually the highest point in the cooling system. If the coolant where to get too low the heater core would starve for hot coolant at idle.

I’m happy to assist further over the phone at https://www.6ya.com/expert/jeremy_d728a59f986299fa