Here's a general guide. Specific steps might vary slightly depending on your exact engine (likely a 3.8L V6). Consult a repair manual specific to your year and model for precise diagrams and torque specifications. A Haynes or Chilton manual is a good investment.
Tools You'll Likely Need:
* Wrench(es): Appropriate sizes to fit the tensioner pulley bolt and any other related bolts (likely metric). A socket wrench set with extensions and a ratchet will be very helpful.
* Socket wrench and ratchet: For easier removal and installation of bolts.
* Jack and jack stands: To safely lift and support the vehicle. Never work under a vehicle supported only by a jack.
* Wheel chocks: To prevent the vehicle from rolling.
* Pry bar or breaker bar: Might be necessary to break loose stubborn bolts.
* New serpentine belt tensioner: Make sure you get the correct replacement part for your specific vehicle.
* New serpentine belt (recommended): Since you'll be removing the belt to access the tensioner, it's a good idea to replace the belt at the same time. A cracked or worn belt is a potential failure point.
* Gloves: To protect your hands.
* Safety Glasses: To protect your eyes from debris.
General Steps:
1. Prepare the Vehicle: Park on a level surface, engage the parking brake, and chock the wheels. Lift the front of the car using the jack and secure it on jack stands.
2. Locate the Tensioner: The tensioner is usually located on the front of the engine, near the serpentine belt. It will have a pulley and a mechanism to apply tension to the belt.
3. Remove the Serpentine Belt: This is crucial before working on the tensioner. Consult your repair manual for the specific routing of the belt. Generally, you'll need to use a wrench or a specialized tool to release the tensioner's mechanism, allowing you to slip the belt off the pulleys.
4. Remove the Tensioner: This is where the specific steps can vary. You'll likely need to remove bolts holding the tensioner in place. There might be a bracket or mounting points involved. Pay close attention to the location of any washers or spacers.
5. Install the New Tensioner: Carefully install the new tensioner, ensuring it's properly aligned with the mounting points. Tighten the bolts to the manufacturer's specifications (found in your repair manual).
6. Install the New Serpentine Belt: Route the new belt around the pulleys according to the diagram in your repair manual. Make sure the belt is properly seated on all pulleys.
7. Lower the Vehicle: Carefully lower the vehicle from the jack stands.
8. Check for Proper Operation: Start the engine and check for any squealing or unusual noises from the belt or tensioner. Also, visually inspect the belt to ensure it's running correctly and not rubbing against anything.
9. Reconnect Battery: Reconnect the negative battery terminal.
Important Considerations:
* Repair Manual: Using a repair manual specific to your 1990 Buick Park Avenue is highly recommended. It will provide detailed diagrams, torque specifications, and other crucial information.
* Difficult Bolts: Some bolts might be rusted or seized. Use penetrating oil (like PB Blaster) to help loosen them. A breaker bar might be necessary.
* Professional Help: If you're not comfortable performing this repair yourself, take your vehicle to a qualified mechanic. Improperly installing the tensioner could damage the belt, pulleys, or even the engine.
This is a general guide; always consult your repair manual for the specific procedures for your vehicle. Improper repair can lead to serious damage. If you are unsure about any step, seek professional help.
