Ignition Coil - Single

Replacement of a single ignition coil on the 2008 Dodge Viper 8.4L V10 engine, including removal of necessary components to access the coil pack.

Warnings

Tools required

Parts

• Ignition coil × 1 — Use OEM specification - Mopar 04606658AC or equivalent
• Spark plug (if damaged during removal) × 1 — Use OEM specification - Champion RC12YC or equivalent

Preparation

1. Park vehicle on level surface and allow engine to cool completely (minimum 2 hours after operation)
2. Disconnect battery negative terminal and wait 2 minutes for system capacitors to discharge
3. Identify which cylinder has the failed coil - cylinders are numbered 1-5 on passenger side (front to rear) and 6-10 on driver side (front to rear)
4. Remove engine cover by releasing spring clips at corners and lifting upward
5. Clean debris from around the target coil area using compressed air to prevent contamination

Procedure

1. 1

   Access the failed ignition coil
   Visually locate the failed coil on the cylinder head. Note the routing of the coil harness connector and any adjacent components. On some cylinders, you may need to temporarily move wiring harnesses or vacuum lines aside for clearance - do not disconnect them unless absolutely necessary. The coils sit directly on top of the spark plugs with individual connectors.
2. 2

   Disconnect the coil electrical connector
   Press the locking tab on the coil connector and pull directly away from the coil body. The connector may be stiff due to heat cycling and dielectric grease. Do not pull on the wiring - grip only the connector body. Inspect the connector terminals for corrosion or damage.
3. 3

   Remove the coil mounting bolt
   Remove the single mounting bolt/fastener securing the coil (verify exact fastener type and size against service documentation for this vehicle). Use a socket or driver with appropriate extension to reach the fastener - access is tight and you may need a universal joint. Keep the fastener in a safe location for reinstallation. Note: Verify fastener type/size and torque against factory service manual; a typical M6 coil bolt is approximately 84-108 in-lb (7-9 ft-lb)
   ℹ️The bolt may have thread locker applied from the factory. Apply steady pressure - do not strip the head.
4. 4

   Extract the ignition coil
   Grasp the coil body firmly and pull straight upward with steady pressure. The coil may be held by the rubber boot seal around the spark plug. Use a twisting motion while pulling if necessary. Do not use excessive force or pry against the coil - this can damage the boot or spark plug ceramic. If the coil is seized, apply penetrating oil around the base and wait 10 minutes before attempting removal again.
5. 5

   Inspect the spark plug and coil boot
   Once the coil is removed, inspect the rubber boot inside the coil. It should be intact with no tears or carbon tracking. Look down into the spark plug tube and inspect the visible portion of the spark plug for fouling, damage, or oil contamination. If oil is present in the spark plug tube, the valve cover gasket may be leaking and should be addressed. Clean any debris from the spark plug tube using compressed air.
6. 6

   Prepare the new ignition coil
   Remove the new coil from packaging and inspect for shipping damage. Apply a thin coat of dielectric grease to the inside of the rubber boot where it will contact the spark plug ceramic insulator. Do not apply excessive grease - a light coating is sufficient to aid future removal and prevent arcing. Also apply a small amount to the coil electrical connector terminals.
7. 7

   Install the new ignition coil
   Align the new coil with the spark plug and mounting hole. Push down firmly and evenly until the coil seats fully onto the spark plug. The coil should sit flush against the valve cover mounting surface. Ensure the coil is properly oriented with the electrical connector facing the correct direction for harness routing.
8. 8

   Secure the coil mounting bolt
   Install the mounting bolt and tighten by hand until snug. Then tighten firmly using the socket and ratchet. The bolt does not require excessive torque - it secures the coil positioning but the boot-to-plug seal provides the primary retention. Overtightening can crack the coil body or strip the valve cover threads.
   ⚠Do not overtighten the mounting bolt. Snug plus approximately 1/4 turn is sufficient. The coil body is plastic and can crack.
9. 9

   Reconnect the electrical connector
   Push the coil connector onto the coil terminal until it clicks into place. Tug gently on the connector body to verify it is locked. Route any wiring or hoses that were moved back to their original positions. Ensure no wires are pinched or stretched.
10. 10

    Reinstall engine cover and reconnect battery
    Position the engine cover over the engine and press down at each corner to engage the spring clips. Reconnect the battery negative terminal. Clear any diagnostic trouble codes using a scan tool if available, or allow the ECM to clear them through normal drive cycle.

Reassembly

1. Ensure the coil connector is fully locked before starting the engine
2. Verify no tools or parts are left in the engine bay
3. The engine cover must be properly seated to prevent interference with moving components

Verification

• Start the engine and verify it runs smoothly without misfires on the replaced cylinder
• Listen for any unusual clicking or arcing sounds from the new coil area
• Use a scan tool to verify no misfire codes are present for the replaced cylinder
• Test drive the vehicle under light and moderate acceleration to confirm smooth operation
• If the check engine light was previously on, verify it does not return after several drive cycles

Related trouble codes on this vehicle

Codes that commonly send this job to the bay — tap one for symptoms, causes, and diagnostic steps.

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