Starter

Remove and replace the starter motor on a 2007-2013 Mercedes-Benz S65 AMG with 6.0L V12 BiTurbo engine, including proper disconnection of electrical connections and torquing to specification.

Warnings

Tools required

Parts

• Starter motor (remanufactured or new) × 1 — Use OEM specification or quality aftermarket
• Starter mounting gasket/O-ring (if equipped) × 1 — Check OEM parts diagram

Preparation

1. Park vehicle on level ground and engage parking brake
2. Allow engine and turbochargers to cool completely (at least 2 hours after operation)
3. Raise and securely support the front of the vehicle on jack stands
4. Remove engine undercover/splash shield if necessary for access
5. Locate the starter motor on the right side (passenger side) of the engine near the transmission bellhousing

Procedure

1. 1

   Disconnect battery
   Open hood and locate the battery. Using a 10mm socket, loosen and remove the negative battery terminal first, then the positive terminal. Secure cables away from battery posts to prevent accidental contact.
2. 2

   Access starter motor area
   From underneath the vehicle, identify the starter motor location on the right side of the engine between the engine block and transmission bellhousing. You may need to remove any heat shields or covers blocking access. Remove heat shield bolts if present.
   Torque spec

   Heat Shield Bolts10 Nm (7 lb-ft)
3. 3

   Disconnect starter electrical connections
   Locate the two electrical connections on the starter solenoid. First, remove the small trigger wire connector by pressing the release tab and pulling straight off. Then, using a 13mm socket, remove the nut securing the large B+ cable to the solenoid post. Remove the cable and position it away from the starter.
   ⚠Mark or photograph electrical connections before removal to ensure correct reassembly.
   Torque spec

   Starter Solenoid Nut12 Nm (9 lb-ft)
4. 4

   Remove ground connection if present
   Check for any ground strap or wire connected to the starter body or nearby mounting point. If present, remove the ground bolt using a 10mm or 13mm socket and position the ground wire away from the work area.
5. 5

   Remove starter mounting bolts
   Locate the starter mounting bolts (typically 2-3 bolts) securing the starter to the transmission bellhousing. The top bolt is usually longer and may require a 12-inch extension with universal joint for access. Using a 16mm socket with appropriate extensions, remove all starter mounting bolts. Support the starter weight as you remove the final bolt.
   ⚠The starter weighs approximately 10-15 lbs. Support it during removal to prevent dropping and causing injury or damage.
   Torque spec

   Starter Mounting Bolts50 Nm (37 lb-ft)
6. 6

   Remove starter motor
   Carefully maneuver the starter motor out of its mounting location. You may need to rotate it and angle it to clear the engine block, transmission, and any nearby components. Work slowly to avoid damaging electrical connectors or coolant lines in the area. Lower the starter down and out from underneath the vehicle.
7. 7

   Inspect mounting area and prepare new starter
   Clean the starter mounting surface on the bellhousing with a wire brush. Inspect the ring gear through the starter opening for damaged teeth. Check the condition of any locating dowels or alignment pins. Verify the new/remanufactured starter matches the old unit and install any gasket or O-ring if equipped.
8. 8

   Install new starter motor
   Position the new starter motor and carefully maneuver it into place, aligning it with the mounting holes and locating dowels on the bellhousing. Ensure any gasket remains properly positioned. The starter pinion gear should mesh correctly with the flywheel ring gear position.
9. 9

   Install and torque mounting bolts
   Thread all starter mounting bolts by hand first to ensure proper thread engagement. Using a torque wrench with appropriate extensions, tighten the mounting bolts to specification in a cross-pattern if multiple bolts are present. Note that the longer bolt may require a 12-inch extension to reach.
   Torque spec

   Starter Mounting Bolts50 Nm (37 lb-ft)
10. 10

    Reconnect electrical connections
    Position the B+ cable over the solenoid post and install the nut. Using a torque wrench with 13mm socket, tighten to specification. Reconnect the small trigger wire connector to the solenoid, ensuring it clicks into place securely.
    Torque spec

    Starter Solenoid Nut12 Nm (9 lb-ft)
11. 11

    Reconnect ground connection
    If a ground wire was removed from the starter or nearby location, reconnect it now and torque the ground bolt to specification using a torque wrench.
12. 12

    Reinstall heat shields and covers
    Reinstall any heat shields or covers that were removed for access. Torque heat shield bolts to specification if applicable.
    Torque spec

    Heat Shield Bolts10 Nm (7 lb-ft)
13. 13

    Reconnect battery
    Reconnect the positive battery terminal first, then the negative terminal. Torque both battery cable nuts to specification using a torque wrench with 10mm socket.

Reassembly

1. Ensure all electrical connections are secure and properly routed away from heat sources and moving parts
2. Verify no tools or parts were left in the engine compartment or under the vehicle
3. Reinstall engine undercover/splash shield if removed
4. Lower vehicle from jack stands

Verification

• Turn ignition to ON position (do not start) and verify no warning lights beyond normal pre-start indicators
• Attempt to start the engine. Starter should engage smoothly without grinding or excessive noise
• Engine should crank at normal speed and start readily
• Listen for any unusual noises from the starter area during cranking
• After engine starts, verify no warning lights on dashboard and that starter disengages properly
• Test start the vehicle 2-3 times from cold to verify consistent operation
• Check for any fluid leaks around the work area after test starts

Related trouble codes on this vehicle

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