Here's a general outline of the process. Specific steps will vary depending on the year and engine of your Expedition. Consult a repair manual specific to your vehicle's year and engine for detailed instructions and torque specifications. These manuals often have diagrams and exploded views that are invaluable.
Tools You'll Likely Need:
* Repair Manual: Absolutely essential.
* Socket set (metric): Various sizes, including deep sockets.
* Wrench set (metric): Various sizes.
* Ratchet(s): Both 3/8" and 1/2" drive are recommended.
* Breaker bar: To loosen stubborn bolts.
* Exhaust manifold gasket set: Get the correct set for your Expedition.
* Penetrating oil (PB Blaster, etc.): Soak bolts liberally beforehand.
* Torque wrench: Crucial for proper tightening to avoid cracking the manifold or head.
* Jack and jack stands: Safety first!
* Wheel chocks: For extra safety.
* Pry bar (carefully): May be needed to help separate manifolds.
* Wire brush: To clean mating surfaces.
* Shop rags: For cleaning.
* Anti-seize compound: Apply to new bolts to prevent future seizing.
General Steps:
1. Safety First: Disconnect the battery negative terminal. Support the vehicle securely on jack stands. Chock the wheels.
2. Access: This varies significantly depending on the year and engine. You'll likely need to remove various components to access the manifolds, potentially including:
* Heat shields
* Catalytic converters (often requires unbolting O2 sensors)
* Oxygen sensors
* Exhaust pipes
* Possibly parts of the engine's intake system
3. Preparation: Generously apply penetrating oil to all the manifold bolts several hours (or even overnight) before attempting to remove them. This greatly increases your chances of success without breaking bolts.
4. Remove Manifold Bolts: Carefully remove all bolts securing the exhaust manifold(s) to the engine head. Use the appropriate tools and take your time. If a bolt breaks, you may need to extract it using an easy-out tool or drill it out.
5. Remove Manifold: Once all bolts are removed, gently separate the manifold from the engine head. A pry bar might be helpful, but use it cautiously to avoid damaging the manifold or engine head.
6. Clean Surfaces: Thoroughly clean the mating surfaces of the engine head and manifold using a wire brush. Remove all old gasket material.
7. Install New Gaskets: Carefully install the new exhaust manifold gaskets, ensuring they are properly seated.
8. Reinstall Manifold: Carefully align the manifold and install it onto the engine head. Tighten the bolts in a star pattern (or as specified in your repair manual), gradually increasing torque. Do not overtighten. Refer to your repair manual for the proper torque specifications.
9. Reassemble: Reinstall all components removed earlier, ensuring that everything is connected correctly.
10. Double Check: Double-check all connections and bolts before starting the engine.
11. Start Engine: Start the engine and check for leaks. Listen carefully for any unusual noises or exhaust leaks. Inspect the exhaust system for leaks visually.
Important Considerations:
* Broken Bolts: This is a common problem. Be prepared to deal with broken bolts. Easy-out tools and/or drilling may be necessary.
* Rust and Corrosion: Rust and corrosion can make this job significantly more difficult. The more time you spend on penetrating oil, the better.
* Torque Specifications: Following the correct torque specifications is crucial to prevent damage.
* Professional Help: If you are not comfortable performing this repair yourself, or encounter unexpected difficulties, it's best to take your vehicle to a qualified mechanic. This is a challenging repair and incorrect installation can lead to serious problems.
This information is for general guidance only. Always consult a repair manual specific to your Ford Expedition's year and engine for detailed instructions and torque specifications. Failure to do so could result in damage to your vehicle or personal injury.
