1. Safety First:
* Disconnect the negative battery terminal. This prevents accidental shorts and protects your vehicle's computer.
* Allow the engine to cool completely. Working on a hot engine is dangerous.
* Gather your supplies: You'll need throttle body cleaner (specifically designed for this purpose – *not* brake cleaner), clean rags or shop towels, a small brush (like a toothbrush), and optionally, compressed air. Gloves are also recommended.
2. Access the Throttle Body:
* Locate the throttle body. It's typically located on the intake manifold, near the air filter housing. Refer to your owner's manual or a repair manual with diagrams for the precise location on your specific Expedition model.
* Disconnect the air intake hose. This will expose the throttle body. The hose usually clamps onto the throttle body; loosen the clamp and carefully remove the hose.
* Disconnect any electrical connectors. There may be sensors or other components connected to the throttle body. Gently unplug them, noting their orientation so you can reconnect them correctly later. Take pictures if you need to.
3. Cleaning the Throttle Body:
* Spray the throttle body cleaner liberally. Focus on the butterfly valve (the plate inside the throttle body) and the surrounding area. Allow the cleaner to soak for a few minutes.
* Gently scrub with the brush. This helps loosen any built-up deposits of carbon, dirt, and oil. Avoid excessive force; you don't want to scratch any surfaces.
* Spray again with the throttle body cleaner. This second application will help rinse away loosened debris.
* Use compressed air (optional). If you have it, carefully blow out any remaining debris. Be mindful of the direction of the air flow to avoid blowing debris deeper into the engine.
* Wipe down the throttle body with clean rags. Thoroughly clean the entire surface, removing any remaining cleaner and residue.
4. Reassembly:
* Reconnect any electrical connectors. Ensure they're securely seated.
* Reconnect the air intake hose. Secure the clamp properly.
* Reconnect the negative battery terminal.
5. Post-Cleaning:
* Start the engine. The engine may idle roughly for a few minutes as the computer relearns the throttle position.
* Monitor the engine. Listen for any unusual sounds or notice any unusual running conditions. If problems persist, consult a mechanic.
Important Considerations:
* Never spray throttle body cleaner directly onto the Mass Airflow Sensor (MAF sensor). This sensor is delicate and can be damaged by the cleaner. If it's very dirty, clean it separately using a dedicated MAF sensor cleaner. The MAF sensor is usually located in the air intake tube *before* the throttle body.
* Be careful not to drop anything into the throttle body. This can cause serious damage to the engine.
* If you're not comfortable performing this task, consult a qualified mechanic.
This procedure provides a general guideline. Always consult a repair manual specific to your 1997 Ford Expedition for detailed instructions and diagrams. Taking pictures during disassembly will be extremely helpful during reassembly.
