However, if you're determined to attempt this yourself, here's a general overview of the steps involved. This is not a complete, step-by-step guide, and you'll need a detailed repair manual specific to your Expedition's engine (4.6L or 5.4L V8) for precise instructions and torque specifications. Improper torque can lead to serious engine damage.
General Steps (This is NOT a complete guide):
1. Safety First: Disconnect the negative battery terminal. Work in a well-ventilated area. Wear safety glasses and gloves.
2. Drain the Oil: Completely drain the engine oil.
3. Remove Necessary Components: This will vary depending on engine access, but generally involves removing:
* Front engine cover: Provides access to the timing chain and oil pump.
* Timing chain cover: May need to remove timing chain tensioner, sprockets and/or guides. This is crucial and requires precise timing chain alignment during reassembly; otherwise, you risk catastrophic engine damage. Consult your repair manual for proper timing chain procedures.
* Oil pump access: This often requires removing other components that are in the way.
* Possibly the oil pan: Depending on the engine design, accessing the oil pump may require oil pan removal.
4. Remove the Oil Pump: This often involves removing bolts securing the pump to the engine block. Be careful not to damage the oil pump gasket or surrounding surfaces.
5. Clean Thoroughly: Clean the oil pump mating surfaces on the engine block.
6. Install the New Oil Pump: Install the new oil pump with a new gasket. Ensure proper alignment and carefully tighten bolts to the manufacturer's specified torque.
7. Reassemble Everything: Carefully reinstall all the components you removed in reverse order. Pay close attention to the timing chain alignment if you removed it.
8. Refill with Oil: Refill the engine with the correct amount and type of oil.
9. Check for Leaks: Check for leaks around the oil pump and other components.
10. Start the Engine: Start the engine and check the oil pressure gauge. Monitor for leaks.
Crucial Considerations:
* Repair Manual: A detailed repair manual specific to your 1999 Ford Expedition's engine is absolutely essential. This will provide detailed instructions, torque specifications, diagrams, and critical information to prevent damage.
* Tools: You'll need a comprehensive set of tools, including specialized tools for timing chain work if necessary.
* Timing Chain Alignment: Misalignment of the timing chain will cause severe engine damage.
* Gaskets and Seals: Use new gaskets and seals throughout the process.
* Oil Pump Pickup Tube: Be cautious not to damage this tube during the process.
Again, this is a complex job. If you're not comfortable with this level of automotive repair, take your Expedition to a qualified mechanic. The potential for costly engine damage from improper installation is extremely high.
