Tools You'll Likely Need:
* Socket wrench set (metric)
* Ratchet and extensions
* Pliers (needle-nose and regular)
* Screwdrivers (Phillips and possibly flathead)
* Vacuum hose removal tool (optional, but helpful)
* New EGR valve (ensure you get the correct part number for your specific Aerostar)
* Shop rags or paper towels
* Safety glasses
* Gloves
Procedure (General Steps):
1. Safety First: Disconnect the negative battery terminal to prevent electrical shorts. Allow the engine to cool completely before starting.
2. Locate the EGR Valve: The EGR valve is typically located on the intake manifold, near the back of the engine. Your repair manual will show its exact location. It might be somewhat difficult to access due to its location.
3. Disconnect Vacuum Hose(s): Carefully disconnect any vacuum hoses connected to the EGR valve. Take note of how they are connected for reassembly. A vacuum hose removal tool can help prevent hose damage.
4. Disconnect Electrical Connector (if applicable): Some EGR valves have an electrical connector. Carefully disconnect it.
5. Remove the EGR Valve: The EGR valve is usually held in place by bolts. Use the appropriate socket to remove these bolts. Be careful not to drop the bolts into the engine bay. The valve itself may be somewhat stiff, requiring some gentle persuasion to remove it.
6. Inspect the Gasket: The EGR valve sits on a gasket. Inspect the gasket for damage. Replace it with a new gasket, even if it looks okay, to ensure a proper seal.
7. Install the New EGR Valve: Position the new EGR valve and gasket onto the intake manifold. Secure it with the bolts you removed earlier, tightening them to the manufacturer's specified torque (found in your repair manual). Do not overtighten.
8. Reconnect Everything: Reconnect the vacuum hoses and the electrical connector (if applicable) in the same manner they were removed. Double-check your connections.
9. Reconnect the Battery: Reconnect the negative battery terminal.
10. Clear the Engine Codes (optional but recommended): After replacing the EGR valve, use an OBD-II scanner to clear any trouble codes that may have been stored in the engine's computer. This is important because the old trouble code might remain, even after fixing the problem.
Important Considerations:
* Accessibility: Access to the EGR valve on the Aerostar can be tight. You might need to use extensions and swivel sockets to reach the bolts.
* Gasket: Replacing the gasket is crucial for a proper seal. A leak can lead to engine problems.
* Torque Specifications: Using the correct torque specifications is critical to prevent damage to the intake manifold or the EGR valve itself.
* Repair Manual: This is not a substitute for a proper repair manual. It's highly recommended to consult your manual for precise instructions and diagrams.
If you are not comfortable performing this repair yourself, it is best to take your vehicle to a qualified mechanic. Improper installation can lead to further engine damage.
