Engine Mount - Front

This procedure covers removal and replacement of the front engine mount on the 2007-2013 Mercedes-Benz S65 AMG with the M275 6.0L V12 BiTurbo engine.

Warnings

Tools required

Parts

• Front engine mount assembly × 1 — Use OEM specification

Preparation

1. Park vehicle on level surface and engage parking brake
2. Allow engine to cool completely
3. Disconnect negative battery terminal
4. Raise front of vehicle and secure on jack stands
5. Remove engine undertray and splash shields for access

Procedure

1. 1

   Install engine support fixture
   Position engine support fixture across the engine bay or place a transmission jack under the oil pan with a block of wood to distribute load. Raise slightly to take tension off the front engine mount. The engine should be just barely supported, not lifted.
2. 2

   Remove mount cover if equipped
   Remove any plastic covers or heat shields covering the front engine mount. These are typically held by clips or bolts.
3. 3

   Disconnect electrical connections
   Locate and disconnect any electrical connectors attached to sensors on or near the front engine mount. On some S65 AMG models, there may be engine position sensors.
4. 4

   Remove mount-to-frame bolts
   Remove the bolts securing the lower portion of the engine mount to the subframe/crossmember. These bolts thread upward from below on most configurations. Note the orientation and number of any spacers or washers.
   Torque spec

   Engine Mount-to-Frame Bolts75 Nm (55 lb-ft)
5. 5

   Remove mount through bolt
   Remove the large center through-bolt that passes through the engine mount assembly. This bolt may require additional support of the engine as it provides the main connection point. Apply penetrating oil if bolt is seized.
6. 6

   Remove engine mount-to-block bolts
   Remove the bolts securing the upper portion of the mount to the engine block. Access may be limited due to turbocharger and exhaust manifold proximity. Use extensions and universal joints as needed.
   Torque spec

   Engine Mount-to-Block Bolts65 Nm (48 lb-ft)
7. 7

   Remove mount assembly
   Carefully extract the front engine mount from between the engine block and subframe. May require slight lifting or lowering of engine using support fixture. Use pry bar if necessary but avoid damaging surrounding components.
8. 8

   Inspect mounting surfaces
   Clean all mounting surfaces on the engine block and subframe. Inspect for cracks, damage, or elongated bolt holes. Check that threaded holes in engine block are clean and free of debris or damaged threads.
9. 9

   Install new mount assembly
   Position new front engine mount between engine block and subframe. Align all mounting holes. May require adjusting engine height slightly with support fixture to align properly.
10. 10

    Install and torque mount-to-block bolts
    Thread in the upper mounting bolts that secure the mount to the engine block. Start all bolts by hand, then torque to specification in a cross pattern.
    Torque spec

    Engine Mount-to-Block Bolts65 Nm (48 lb-ft)
11. 11

    Install and torque through bolt
    Insert the main through-bolt through the mount assembly and torque to specification. Ensure any washers or spacers are properly positioned.
12. 12

    Install and torque mount-to-frame bolts
    Install the lower mounting bolts that secure the mount to the subframe. Torque to specification. Verify all fasteners are properly seated.
    Torque spec

    Engine Mount-to-Frame Bolts75 Nm (55 lb-ft)
13. 13

    Reconnect sensors and covers
    Reconnect any electrical connectors to sensors. Reinstall any covers or heat shields removed earlier and torque cover bolts to specification.
14. 14

    Remove engine support and lower vehicle
    Carefully remove the engine support fixture or transmission jack. Reinstall undertray and splash shields. Lower vehicle from jack stands and reconnect battery negative terminal.

Reassembly

1. Ensure all electrical connectors are properly seated and secured
2. Verify all fasteners have been torqued to specification
3. Check that no tools or parts were left in engine bay

Verification

• Start engine and verify no abnormal vibration or movement
• With engine running, have assistant shift transmission through gears while monitoring engine movement - should be minimal
• Check for any unusual noises from mount area during engine start and shutdown
• Test drive vehicle and verify smooth acceleration with no excessive engine movement or clunking sounds

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