Here's a general outline; however, this is not a substitute for a repair manual specific to your vehicle's year and engine. Always consult a repair manual for precise instructions, torque specifications, and safety precautions.
Tools You'll Likely Need:
* Jack and jack stands: Essential for safely lifting the vehicle.
* Wheel chocks: To prevent the vehicle from rolling.
* Socket set and wrenches: Various sizes to remove bolts and nuts.
* Ratchet and extensions: For accessing hard-to-reach fasteners.
* Wrench for serpentine belt tensioner: This is crucial to remove the serpentine belt. The type depends on your specific vehicle – some use a pivot bolt, others a locking mechanism.
* New idler pulley: Ensure you get the correct replacement part for your specific engine.
* Gloves: Protect your hands.
* Safety glasses: Protect your eyes.
* Shop rags: For cleaning.
* Possibly a pulley puller: Depending on how stubborn the old pulley is.
General Steps (Consult your repair manual for precise details):
1. Disconnect the battery: This is crucial to prevent electrical shorts and accidental activation of the engine.
2. Raise and support the vehicle: Securely lift the vehicle using a jack and place it on jack stands. Never work under a vehicle supported only by a jack.
3. Locate the idler pulley: It's part of the serpentine belt system and usually easily identifiable.
4. Remove the serpentine belt: This is the most challenging part. You'll need to use the appropriate tool to release tension on the belt tensioner. The belt may be routed in a complex path; carefully observe how it's routed before removing it so you can put the new one back on correctly.
5. Remove the idler pulley: This usually involves removing one or more bolts that hold the pulley to its bracket. You might need a pulley puller if the pulley is stuck.
6. Install the new idler pulley: Make sure the pulley is properly aligned and seated before tightening the bolts. Use the specified torque values from your repair manual.
7. Reinstall the serpentine belt: Follow the routing diagram carefully and ensure the belt is properly seated on all pulleys.
8. Lower the vehicle: Carefully lower the vehicle from the jack stands.
9. Reconnect the battery: Reconnect the battery terminals.
10. Check the belt tension: Make sure the serpentine belt has the correct tension.
11. Test the engine: Start the engine and check for any unusual noises or belt slippage.
Important Considerations:
* Belt routing: The serpentine belt has a specific routing. Incorrect routing can damage the belt and other components. Pay close attention to this step.
* Torque specifications: Always use the torque specifications provided in your repair manual. Over-tightening can damage the pulley or bracket. Under-tightening can lead to the pulley coming loose.
* Pulley puller: If the old pulley is stuck, you'll likely need a pulley puller to remove it without damaging the bracket.
This is a simplified explanation. Again, it's strongly recommended that you consult a repair manual specific to your 1999 Chevy Malibu V6 before attempting this repair. If you're not comfortable performing this repair yourself, take your vehicle to a qualified mechanic. Improper repair can lead to serious damage to your engine and potentially injury.
