Q: How to remove a heater core on Toyota Matrix and Pontiac Vibe?
A: To remove the heater core, start by disconnecting the battery cable and draining the cooling system. Then, disconnect the heater hoses at the firewall and remove various components such as the center console, glove compartment, and instrument panel. Disconnect major electrical harnesses and remove the cross-cowl support tube. The heating/air conditioning components are in plastic housings connected to the interior side of the firewall, which must be unbolted and pulled out far enough for the heater core tubes to come through the firewall into the interior. Remove the heater core from the housing and keep towels or rags on the carpeting to catch any coolant that may drip. To install, simply reverse the removal steps and refill the cooling system, reconnect the battery, and check for leaks and proper system operation.