1. Preparation:
* Safety First: Disconnect the negative battery terminal. Use jack stands securely when working under the car. Wear safety glasses and gloves.
* Gather Tools and Parts: You'll need a comprehensive set of wrenches, sockets, screwdrivers, a torque wrench, jack and stands, an engine hoist or crane (highly recommended), possibly a transmission jack, new gaskets and seals, fluids (oil, coolant, etc.), and the replacement engine. Have your new engine ready to install. Consider disposable shop towels and engine degreaser.
* Workspace: Work in a well-lit, clean area with adequate space.
* Removal of Related Components: Before engine removal, you may need to disconnect and remove various components such as:
* Battery and battery tray: To gain access.
* Air intake system: Intake tube, air filter housing.
* Exhaust system: Exhaust manifolds and related components may need to be unbolted at least partially.
* Wiring harness: Carefully disconnect all electrical connectors related to the engine, labeling each connection as you go to aid in reassembly.
* Cooling system: Drain the coolant. Disconnect radiator hoses, heater hoses.
* Fuel lines: Disconnect the fuel lines; take precautions to prevent fuel spillage. May require fuel pressure relief.
* Transmission: Depending on the transmission type (automatic or manual), the transmission may need to be disconnected. This is often one of the most challenging parts of the process.
* Power Steering lines: Disconnect the power steering lines, if applicable.
2. Engine Removal:
* Support the Engine: Securely attach the engine hoist to the engine's lifting points. These points are usually on the engine block.
* Disconnect Remaining Components: Disconnect any remaining components that are still attached to the engine.
* Unbolt the Engine Mounts: Carefully unbolt the engine mounts that secure the engine to the chassis.
* Slowly Lift and Remove: Slowly lift the engine using the hoist, being mindful of any obstacles. Carefully maneuver the engine out of the engine bay.
3. Engine Installation (Reverse of Removal):
* Position the New Engine: Carefully lower the new engine into the engine bay using the hoist.
* Reconnect Components: Reconnect all previously disconnected components in the reverse order of removal, ensuring all connections are secure and properly torqued.
* Reconnect Transmission (if applicable): Carefully reconnect the transmission.
* Fill Fluids and Check Levels: Add the necessary fluids (oil, coolant, transmission fluid, power steering fluid) and check the levels.
* Check for Leaks: Inspect for any leaks after starting the engine.
* Test Drive: After a thorough inspection, take the vehicle for a short test drive to verify proper engine function.
Important Considerations:
* Transmission: Removing and reinstalling the transmission is often the most difficult part of this process, requiring specialized tools and knowledge.
* Torque Specifications: Accurate torque specifications are crucial to prevent damage. Use a torque wrench and consult your repair manual.
* Professional Help: If you're not comfortable with this level of auto repair, it's best to seek professional help from a qualified mechanic. This is a major job with potential for serious injury or damage if done improperly.
This is a simplified overview. The specifics will vary greatly depending on the exact engine in your 1990 Mustang (e.g., 2.3L, 5.0L). Always refer to a factory service manual or a reputable repair manual specific to your vehicle's year and engine.
