Ignition Coils - All

This procedure replaces all twelve ignition coils on the 2009 Aston Martin DB9 6.0L V12 engine, requiring removal of engine covers and access to both cylinder banks.

Warnings

Tools required

Parts

• Ignition coil × 12 — Use OEM specification
• Spark plug × 12 — Use OEM specification (NGK recommended)

Preparation

1. Park vehicle on level surface and engage parking brake
2. Ensure engine is completely cold to the touch
3. Disconnect negative battery terminal and wait 10 minutes for capacitor discharge
4. Remove engine cover by releasing quick-release fasteners (typically twist-lock or pull-up style depending on production batch)
5. Photograph or label all electrical connectors for reference during reassembly

Procedure

1. 1

   Remove upper plenum covers
   Remove the upper engine aesthetic covers to expose the ignition coil area. These covers are typically secured with rubber grommets on posts and may have 2-4 Torx fasteners at the rear. Lift covers straight up once fasteners are released.
2. 2

   Access left cylinder bank (driver side)
   The left bank is accessed from the driver side. Identify all six ignition coils mounted individually over the spark plugs along the cam cover. Verify cylinder numbering and bank identification against factory service documentation before proceeding. Note: The left bank is accessed from the driver side. Identify the six ignition coils mounted individually on top of the cam cover, one per cylinder. Verify cylinder numbering against the Aston Martin workshop manual before proceeding, as bank/cylinder identification must be confirmed for this specific engine. Note: The left bank is accessed from the driver side. Identify all six ignition coils positioned along the top of the cam cover, one per cylinder. Confirm the cylinder numbering for this bank against Aston Martin service documentation before labeling fasteners, as bank/cylinder assignment is platform-specific.
3. 3

   Disconnect left bank coil connectors
   Disconnect the electrical connector from each of the six coils on the left bank. Press the release tab (typically on the side or top of connector) and pull straight up or away. Do not pull on wires. If connectors are stuck due to age, gently rock side-to-side while pulling.
4. 4

   Remove left bank ignition coils
   Each coil is secured by a single retaining bolt at its base (verify fastener type and size against factory documentation). Remove the bolt from each coil and store fasteners in organized manner by cylinder position. Pull coils straight up with steady pressure - they may resist due to spark plug boot seal. Do not twist excessively. Inspect coil boots for cracks or carbon tracking. Note: Each coil is secured by a single bolt at its base; verify the exact fastener type and size against the Aston Martin workshop manual before selecting a driver. Note: Each coil is secured by a single small bolt at its base (confirm fastener type and size against service documentation before removal).
   Torque spec

   Ignition Coil Bolt8 Nm (6 lb-ft)
5. 5

   Clean left bank spark plug wells
   Use compressed air or vacuum to remove all debris from each spark plug well before removing plugs. Any debris that falls into the cylinder can cause severe damage. Inspect wells for oil accumulation, which may indicate valve cover gasket leakage.
6. 6

   Remove left bank spark plugs
   Using a thin-wall spark plug socket of the correct hex size for this engine (verify against the workshop manual) with extension, carefully remove each spark plug. Turn counter-clockwise and maintain straight alignment to avoid cross-threading. If plugs are tight, apply penetrating oil and wait 15 minutes. Inspect plug condition and gaps for diagnostic information about engine health.
   ⚠Aluminum cylinder heads are easily damaged by cross-threading. If plug binds during removal, stop and reassess angle before continuing.
7. 7

   Install left bank spark plugs
   Do not apply anti-seize to modern plated spark plug threads unless specifically required; NGK plugs are pre-coated and adding anti-seize can lead to over-torque and thread damage. Thread each new plug clean and dry. Hand-thread each plug carefully until fully seated, then torque to specification using a torque wrench. Work methodically through all six cylinders. Note: Do not apply anti-seize to modern plated spark plug threads unless specified by the manufacturer; install plugs dry and torque to specification to avoid over-torquing aluminum heads. Note: Do not apply anti-seize to modern plated spark plugs unless specifically required by the plug manufacturer, as it can cause over-torquing and thread damage in aluminum heads. Install plugs with clean, dry threads.
   ⚠Critical: Do not over-torque spark plugs. Aluminum heads strip easily and repair requires helicoil installation or head removal.
   Torque spec

   Spark Plugs - Aluminum Head15 Nm (11 lb-ft)
8. 8

   Install left bank ignition coils
   Apply a small amount of dielectric grease to the inside of each coil boot. Install each coil by aligning with the spark plug and pressing firmly until fully seated - you should feel it snap onto the plug terminal. Install the coil retaining bolt and torque to specification. Reconnect electrical connectors, ensuring they click into place. Note: Install the coil hold-down bolt and torque to specification (confirm fastener type and torque against service documentation).
   Torque spec

   Ignition Coil Bolt8 Nm (6 lb-ft)
9. 9

   Access right cylinder bank (passenger side)
   Move to the right bank (passenger side). Access is similar to left bank. Verify the right bank cylinder numbering and order against the Aston Martin workshop manual before proceeding. Depending on vehicle configuration, additional hoses or wiring may need to be moved aside for access. Note: Move to the right bank (passenger side). Access is similar to left bank. Confirm this bank's cylinder numbering against Aston Martin service documentation before labeling fasteners, as bank/cylinder assignment is platform-specific.
10. 10

    Disconnect right bank coil connectors
    Disconnect the electrical connector from each of the six coils on the right bank using the same technique as left bank. Press release tabs and pull connectors straight off.
11. 11

    Remove right bank ignition coils
    Remove the coil retaining bolt from each coil on the right bank. Pull coils straight up from their wells. Inspect boots for damage as before.
    Torque spec

    Ignition Coil Bolt8 Nm (6 lb-ft)
12. 12

    Clean right bank spark plug wells
    Thoroughly clean each spark plug well using compressed air or vacuum, ensuring no debris remains that could enter cylinders during plug removal.
13. 13

    Remove right bank spark plugs
    Remove all six spark plugs from the right bank using the same careful technique as left bank. Maintain straight socket alignment and inspect each plug upon removal.
    ⚠Exercise the same care with aluminum threads as on left bank. Cross-threading risk is identical.
14. 14

    Install right bank spark plugs
    Install plugs with clean, dry threads (do not apply anti-seize to modern plated plugs unless the plug manufacturer requires it) and hand-thread into position. Torque each plug to specification using torque wrench. Note: Do not apply anti-seize to modern plated spark plug threads unless specifically required by the manufacturer; install plugs clean and dry. Hand-thread each new plug into position, then torque each plug to specification using a torque wrench.
    Torque spec

    Spark Plugs - Aluminum Head15 Nm (11 lb-ft)
15. 15

    Install right bank ignition coils
    Apply dielectric grease to coil boots and install each coil, pressing firmly until seated on spark plug terminal. Install and torque the coil retaining bolts. Reconnect all electrical connectors with positive click confirmation.
    Torque spec

    Ignition Coil Bolt8 Nm (6 lb-ft)
16. 16

    Reinstall engine covers
    Reinstall the upper plenum covers and engine cover in reverse order of removal. Ensure all fasteners are properly seated and grommets are aligned with posts.
17. 17

    Reconnect battery and clear codes
    Reconnect the negative battery terminal. If available, use a diagnostic scanner to clear any stored ignition system fault codes that may have been present before the repair.

Reassembly

1. Verify all twelve electrical connectors are fully seated with audible clicks
2. Ensure no tools or parts are left in engine bay before closing covers
3. Double-check that all engine covers and fasteners are properly reinstalled

Verification

• Start engine and listen for smooth idle with no misfires or irregular firing
• Allow engine to reach operating temperature and verify no fault codes are present
• Perform a test drive including moderate acceleration to confirm all cylinders are firing correctly
• Inspect for any visible spark arcing around coils during darkness (engine running) if misfire symptoms persist
• Monitor for any oil seepage from valve covers into spark plug wells over next several days

Related trouble codes on this vehicle

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