Here's a general outline of the process. This is not a substitute for a proper repair manual specific to your E46's year and engine. Variations exist between models and engine types. Consult a repair manual (like a Bentley manual) for detailed instructions and diagrams specific to your vehicle.
Tools You'll Likely Need:
* Socket set (metric) with various extensions and a ratchet
* Torque wrench
* Jack and jack stands (crucial for safety)
* Wheel chocks
* Pry bar or similar tool
* Wire brush
* Penetrating oil (like PB Blaster)
* New starter motor (ensure you get the correct one for your vehicle)
* Possibly a battery terminal cleaner
Steps (General Outline - Consult your repair manual for specifics):
1. Safety First: Disconnect the negative battery terminal. This is paramount to prevent electrical shocks and short circuits.
2. Access the Starter: This is the most challenging part. The starter motor is typically located on the transmission bell housing, near the bottom of the engine. Access varies depending on the engine (M54, M43, etc.). You'll likely need to:
* Raise the vehicle safely using a jack and jack stands.
* Securely chock the wheels.
* Remove the undertray (if equipped).
* Possibly remove some components to improve access. This might include the air intake system, heat shields, and potentially parts of the exhaust system. Your repair manual will show what needs to be removed.
3. Disconnect the Electrical Connections: Carefully disconnect the starter motor's electrical wiring harness connector(s). Take pictures or make notes to ensure you reconnect them correctly. The wires are usually held in place by clips or screws. Use a wire brush to clean the terminals for good contact.
4. Remove the Starter Bolts: The starter is typically held in place by two or three bolts. These bolts can be very stubborn, so apply penetrating oil liberally and let it sit for a while before attempting to remove them. Use the appropriate socket and ratchet to loosen and remove the bolts.
5. Remove the Starter: Once the bolts are removed, carefully remove the starter motor. It may be slightly tight against the bell housing. A gentle pry bar might be necessary, but be extremely careful not to damage any components.
6. Install the New Starter: Carefully install the new starter motor in reverse order of removal. Make sure it's seated correctly and aligned.
7. Reconnect Everything: Secure the starter with the bolts and torque them to the manufacturer's specifications (found in your repair manual). Reconnect the electrical wiring harness connectors. Double-check all connections.
8. Reassemble: Reinstall any components you removed to access the starter (undertray, heat shields, etc.).
9. Lower the Vehicle: Carefully lower the vehicle from the jack stands.
10. Reconnect the Battery: Reconnect the negative battery terminal.
11. Test the Starter: Attempt to start the engine.
Important Considerations:
* Repair Manual: This is absolutely essential. The steps above are a general overview, and specific procedures vary considerably between E46 models.
* Torque Specifications: Use a torque wrench to tighten the starter bolts to the manufacturer's specifications. Over-tightening can damage the starter or the bell housing.
* Cleanliness: Keep the area clean to prevent debris from entering the engine compartment.
* Professional Help: If you're not comfortable performing this repair yourself, take your car to a qualified mechanic.
This is a complex repair with potential for damage if not done correctly. Always consult a repair manual specific to your E46 before attempting this work. Improper repair could lead to further damage to your vehicle.
