If you lack experience with automotive repair, strongly consider taking your vehicle to a qualified mechanic. It's far less likely to result in additional problems and ultimately save you money.
However, if you're determined to do it yourself, here's a *general* overview. Specific steps will vary slightly depending on the exact Malibu model and trim level. You'll need a detailed repair manual specific to your 1999 Chevrolet Malibu to accurately follow the procedure. A Haynes or Chilton manual is a good investment.
General Steps (Expect Variations):
1. Disconnect the Battery: This is crucial for safety to prevent electrical shorts.
2. Drain the Cooling System: Completely drain the coolant from the engine and radiator.
3. Access the Heater Core: This usually involves removing parts of the dashboard. This is the most labor-intensive part of the job. You'll likely need to remove:
* Steering column shrouds.
* Glove compartment.
* Possibly parts of the dashboard itself. This may require removing screws, clips, and potentially disconnecting electrical connectors.
4. Disconnect Heater Core Hoses: Carefully disconnect the heater core hoses. Be prepared for some coolant to spill, so have rags ready.
5. Remove the Heater Core: This often involves accessing the heater core from behind the dashboard, usually by removing the housing it's in. Expect this to be a tight squeeze.
6. Install the New Heater Core: Carefully install the new heater core, ensuring a proper seal.
7. Reconnect Heater Core Hoses: Reconnect the heater core hoses, tightening the clamps securely but not over-tightening.
8. Reassemble the Dashboard: Carefully reassemble the dashboard components in reverse order of removal. Take pictures as you disassemble it to help with reassembly.
9. Refill and Bleed the Cooling System: Refill the cooling system with the correct type and amount of coolant. Bleed the system to remove any air pockets. This is essential to prevent overheating and damage.
10. Test the System: Run the engine and test the heater to ensure proper operation and check for leaks.
Tools You'll Likely Need:
* Socket set
* Wrenches (various sizes)
* Screwdrivers (Phillips and flathead)
* Pliers
* Flashlight
* Repair manual specific to your 1999 Chevrolet Malibu
* Drain pan
* New heater core
* Coolant
* Rags
* Safety glasses
* Gloves
Again, this is a simplified overview. Refer to a repair manual specific to your 1999 Chevrolet Malibu for detailed instructions and diagrams. Attempting this repair without proper knowledge and tools can lead to significant damage and increased repair costs. If you have any doubts, take your car to a professional.
