Engine Mount - Front

This procedure covers the removal and replacement of the front engine mount on a 2009 Aston Martin DB9 with the 6.0L V12 engine, requiring engine support and subframe access.

Warnings

Tools required

Parts

• Front engine mount assembly × 1 — Use OEM specification
• Engine mount hardware kit (if corroded) × 1 — Use OEM specification

Preparation

1. Park vehicle on level surface and engage parking brake.
2. Allow engine to cool completely if recently operated.
3. Disconnect negative battery terminal and secure cable away from battery post.
4. Raise vehicle using a lift or floor jack and support securely on jack stands at manufacturer-specified lift points.
5. Remove front undertray panels to access engine bay from below. These typically use Torx fasteners around the perimeter.
6. Inspect the front engine mount location to verify which mount requires replacement (driver or passenger side).

Procedure

1. 1

   Support the engine weight
   Install an engine support fixture across the engine bay, hooking to the engine lift points, or position an overhead engine hoist with chains attached to the engine lift brackets. Take up slack until the support fixture or hoist begins to bear the engine's weight, but do not lift the engine yet. The goal is to prevent engine movement once the mount is removed.
2. 2

   Locate the front engine mount
   From below the vehicle, identify the front engine mount assembly. The 2009 DB9 6.0L V12 on the VH platform uses left-side and right-side engine mounts (hydraulic isolators) that connect the engine to the subframe; there is no discrete single 'front' mount. Confirm which side mount is being serviced before proceeding, and treat the 'front engine mount' job as the forward/driver-or-passenger-side mount as applicable. The mount consists of a rubber isolator assembly with mounting brackets on both the engine side and frame side.
3. 3

   Remove engine mount through-bolt
   If the mount uses a central through-bolt design, locate the through-bolt that passes through the center of the mount assembly securing the engine bracket to the mount body. Verify the actual fastener layout against Aston Martin DB9 service data, as the VH-platform hydraulic mount may instead use separate bracket-to-mount bolts rather than a single through-bolt. Using a socket and breaker bar if necessary, remove this through-bolt completely. Note the orientation of any washers or spacers for reinstallation.
   Torque spec

   Engine Mount Through-Bolt85 Nm (63 lb-ft)
4. 4

   Remove engine-side mount bolts
   Identify the bolts securing the engine mount bracket to the engine block. These bolts secure the bracket to the block (verify exact bolt count against Aston Martin DB9 service data); they are accessed from below or through the wheel well. Remove these bolts completely using the appropriate socket. Support the mount assembly as you remove the final bolt to prevent it from falling.
5. 5

   Raise engine slightly
   Using the engine support fixture or hoist, carefully raise the engine approximately 10-15mm to relieve pressure on the mount and create clearance for removal. Monitor the engine position and ensure no hoses, wiring, or components are under tension.
6. 6

   Remove frame-side mount bolts
   Locate the bolts securing the lower portion of the engine mount to the subframe or crossmember. These bolts secure the lower mount to the subframe (verify exact bolt count against Aston Martin DB9 service data); they are accessed from below. Remove these bolts completely using the appropriate socket.
   Torque spec

   Engine Mount-to-Frame Bolts75 Nm (55 lb-ft)
7. 7

   Remove engine mount assembly
   With all fasteners removed and the engine slightly raised, carefully maneuver the engine mount assembly out from between the engine and subframe. It may be necessary to rotate or angle the mount to clear surrounding components. Use a pry bar gently if needed, but avoid damaging the engine block or frame surfaces.
8. 8

   Inspect mounting surfaces and hardware
   Clean the engine block mounting surface and subframe mounting surface using a wire brush or scraper to remove any corrosion, old thread locker, or debris. Inspect all bolt threads for damage or excessive corrosion. Inspect the engine bracket and frame bracket for cracks, deformation, or excessive wear. Replace hardware if threads are damaged.
9. 9

   Position new engine mount
   Position the new engine mount assembly between the engine and subframe, aligning the mounting holes. Ensure any locating pins or alignment features are properly engaged. The mount orientation is critical—verify the mount is not inverted or rotated incorrectly by comparing to the old mount.
10. 10

    Install frame-side mount bolts
    Install the bolts securing the lower portion of the engine mount to the subframe. Start all bolts by hand to ensure proper thread engagement. Tighten bolts in a cross pattern to the OEM-specified torque value (verify engine mount-to-frame torque in Aston Martin DB9 service data before final tightening).
    Torque spec

    Engine Mount-to-Frame Bolts75 Nm (55 lb-ft)
11. 11

    Lower engine onto mount
    Using the engine support fixture or hoist, carefully lower the engine onto the new mount until the engine bracket mounting holes align with the mount. Ensure the mount is not twisted or misaligned as the engine weight is transferred.
12. 12

    Install engine-side mount bolts
    Install the bolts securing the engine mount bracket to the engine block. Start all bolts by hand to ensure proper thread engagement. Tighten bolts in a cross pattern to the OEM-specified torque value (verify engine mount-to-block torque in Aston Martin DB9 service data before final tightening).
    Torque spec

    Engine Mount-to-Block Bolts49 Nm (36 lb-ft)
13. 13

    Install engine mount through-bolt
    Insert the through-bolt through the center of the mount assembly, ensuring any washers or spacers are installed in the correct orientation as noted during removal. Tighten the through-bolt to the OEM-specified torque value (verify engine mount through-bolt torque in Aston Martin DB9 service data before final tightening).
    Torque spec

    Engine Mount Through-Bolt85 Nm (63 lb-ft)
14. 14

    Remove engine support and verify installation
    Carefully remove the engine support fixture or hoist, allowing the engine weight to fully transfer to the mounts. Check that the engine sits level and that there is no visible misalignment. Inspect all bolts visually to ensure none have backed out.
15. 15

    Reinstall undertray and lower vehicle
    Reinstall the front undertray panels using the original Torx fasteners. Ensure all fasteners are secure. Lower the vehicle from jack stands or lift. Reconnect the negative battery terminal.

Reassembly

1. All fasteners must be torqued to specification using a calibrated torque wrench.
2. Ensure no tools, rags, or parts are left in the engine bay or under the vehicle before lowering.
3. Do not skip the engine support step—attempting to remove a mount without proper support is extremely dangerous.

Verification

• Start the engine and allow it to idle. Listen for abnormal vibrations or knocking sounds that would indicate improper mount installation.
• With the engine running, gently apply throttle while watching the engine for excessive movement. The engine should remain stable with minimal visible motion.
• Perform a test drive and note any changes in vibration at idle, during acceleration, or at highway speeds. Properly installed mounts should eliminate previous vibration issues.
• After the first 50-100 miles of driving, re-check all mount bolt torque values to ensure none have loosened.

Related trouble codes on this vehicle

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