It is a tough job, you will need to remove your front seat, it will be nearly impossible if you don't have all the room that you will need. It will be difficult to work with the front seat in place but, if you do it, it can be done. I say remove the seat because it will be much easier to work without it. there are only four bolts holding it on anyhow. Okay, let's get down to it. You will need to remove your inner fender skirt (the plastic fender)You will need to remove all the bolts and or nuts holding your fan blower cover to the firewall, there are either eight or nine to remove. After those are removed, take off the housing, also take off the ground and your realay switch,go to the interior of the car and wiggle the interior plastic housing loose, now comes the tricky part, there are small screws holding an aluminum cover over the heater core, remove all these small screws, also remove any rubber grommets, now wiggle that loose, you can use a screw driver to get it loose where it is stuck, DON'T force it, now reach in a pull out the heater core, go in reverse to put it back together. Hope this helps, I just did one myself.
how do you change a heater core on a 2003 ss Monte Carlo
How do you install a new heater core on a 1979 chevy monte carlo?
Under the dash
heater core
To change the heater core in a 1972 Monte Carlo, first, disconnect the battery and drain the coolant from the system. Next, remove the dashboard and the heater box to access the heater core; this typically involves unscrewing various bolts and disconnecting the heater hoses. Once you have access, remove the old heater core and replace it with the new one, ensuring all connections are secure. Finally, reassemble the dashboard and refill the cooling system with coolant, checking for leaks before starting the vehicle.
Your heater core is likely bad
Low coolant? Bad thermostat? Heater control cable not adjusted properly? Heater core airbound? Heater core plugged?
They are on the backside of the engine and go into the firewall.jd
On the passenger compartment side of the firewall, up and under the dash.
To replace the heater core in a 2003 SS Monte Carlo, start by disconnecting the negative battery cable and draining the coolant. Remove the dashboard and center console to access the heater core housing, followed by disconnecting the heater hoses and any electrical connections. After removing the bolts securing the heater core, carefully extract it from the housing and install the new one, reassembling everything in reverse order. Finally, refill the coolant, bleed the system, and reconnect the battery.
This is sort of a difficult job. The black housing under the hood (on the passanger side) has to be removed. The heater core is mounted inside that housing.
Heater temperature control valve.