How to Replace the Heater Core in an Oldsmobile Alero

How to Replace the Heater Core in an Oldsmobile Alero. If your Oldsmobile Alero is one of the last models produced, replacing the heater core is best left to an expert. This is because the entire instrument panel must be removed from the inside to reach the heater assembly. If you have a slightly older model, 2002 or earlier, there's much less you must remove on the dashboard, making this repair easier. These steps are for the 2002 and older models only.

Disconnect the negative cable from the Oldsmobile Alero's battery. While the car is securely raised on jack stands, drain the engine coolant into a clean container. Most models don't have a drain plug on the bottom of the radiator, so you must take off the lower radiator hose to drain the system.

Remove the drain tube from the heater's housing and disconnect the heater hoses from the core. Take off the center console, if one is equipped. Then, take off the sound insulators on both sides of the car, the steering column's opening filler, the air outlet duct and the floor air outlet to reach the heater core.

Disconnect the heater core cover. Remove the core-to-housing mounting clamps and remove the heater core.

Install the replacement heater core. Connect the mounting clamps and replace the core cover.

Replace the rear floor air outlet, air outlet duct, steering column opening filler, sound insulators and center console (if equipped). Reattach the heater hoses to the core and the drain tube to the housing.

Fill the cooling system, using new coolant if the old liquid doesn't appear clean. Be sure the lower radiator hose is securely back in place before filling the radiator. Reconnect the negative battery cable.

Start up the Oldsmobile Alero's engine and let it run until it reaches normal operating temperature. Observe the climate control operation and check for any leaks in the system.