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Mercedes-Benz E-Class AMG: How to Replace Ignition Coils

Modern distributor-less ignition systems utilize coil packs to electronically control spark to each spark plug. Generally, these ignition coil packs are robust and fairly reliable; however, they can occasionally fail and cause an engine misfire. Learn how to replace your ignition coils here.

By Joseph Coelho - June 2, 2015

This article applies to the Mercedes-Benz E-Class AMG w211 (2002-2009).

Modern ignition systems on today's engines utilize individual coils per cylinder. Individual coil packs are a vast improvement over a traditional distributor ignition system because they have fewer moving parts, are smaller, less bulky, and provide much improved spark for the engine. In turn, this allows for greater performance, cleaner emissions, improved fuel economy, and lengthened service intervals. While these coils are typically reliable, they can break down and fail from the continuous heat buildup and high voltage that is transferred through them. There are a variety of tools available to test the condition of ignition coils. Also, they can often be inspected for signs of cracking and deterioration. So, whether you have an engine misfire or are performing preventative maintenance, this article will guide you through ignition coil replacement for the Mercedes-Benz E63 and E55 AMG models.

Materials Needed

  • Torx bits or Torx drivers
  • Ratchet and extensions
  • Screwdriver
  • Torque wrench
  • Dielectric grease

It is highly recommended that spark plugs and spark plug wires (E55 only) also be replaced when installing new ignition coils. High resistance in an old spark plug or plug wire can cause premature ignition coil failure.

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Step 1 – Remove intake components

Both the E55 and E63 AMG models require the removal of air intake components.

  • Remove the front engine cover. Lift it straight up and out of the engine bay.

  • Figure 1. E63 AMG engine cover removal.
  • Figure 2. E55 AMG engine cover removal.
  • Disconnect the plastic air intake tubes running to each airbox.
  • Disconnect hose clamps on the backside of each airbox.
  • Disconnect both mass air flow (MAF) sensor plugs (E63 AMG only).
  • Figure 3. E63 MAF plugs and hose clamps.
  • Figure 4. E55 airbox removal points.

  • Lift the airbox assemblies out of the engine bay.

  • Figure 5. E63 airbox assemblies.
  • Figure 6. E55 airbox assemblies.

Step 2 – Remove ignition coils

With the engine cover and airboxes removed, the ignition coils are visible.

  • Figure 7. E63 coil locations.
  • Figure 8. E55 coil locations.

E63 Coils

The E63 uses a coil-on-plug design that does not utilize a spark plug wire.

  • Unclip the electrical connector at each coil you are replacing. Depress the locking tab, and release the clip to pull the plug away from the coil. This is typically best accomplished with the coil still mounted to the engine for more leverage.
  • Remove the (two) T30 Torx screws securing the coil in place.

  • Remove the coil from the engine. It may take a bit of wiggling to break free.

  • Figure 9. E63 coil electrical connector removal.
  • Figure 10. E63 coil being removed from engine.

E55 Coils

The E55 uses a dual coil/dual spark plug per cylinder configuration. This car also uses spark plug wires.

  • Remove each spark plug wire from its companion spark plug.
  • Remove the Torx fasteners securing the coil packs to the engine.

  • Lift the coil packs and spark plug wires up onto the top of the engine. The spark plug wires and electrical harness connector to each coil can now be removed. The coil should now be free and can be replaced.

  • Figure 11. E55 coils with spark plug wires removed.
  • Figure 12. E55 electrical harness connector removed from coil.

Step 3 – Install new coils and reassemble

E63

  • Install the new coil packs, making sure they are firmly attached to their adjoining spark plugs.
  • Install Torx fasteners and torque to 15 ft-lbs.
  • Reconnect electrical connector to its companion coil. Listen for the audible click of the locking tab of the connector to ensure it is properly installed.
  • Re-install airbox assemblies, reconnect mass air flow sensor plugs, tighten the hose clamps at the y-pipe, and reconnect plastic air intake tubes.
  • Re-install front engine cover.

  • Start the car to ensure the engine is running smoothly with no check engine lights.

Figure 13. E63 ignition coil.

E55

  • Install spark plug wires onto the new coil packs.
  • Reconnect electrical connector to each coil.
  • Install coils back onto the engine. Torque the Torx fasteners to 15 ft-lbs.
  • Reconnect spark plug wires to spark plugs, making sure they are fully seated.
  • Re-install the airbox assemblies, plastic air intake tubes, and tighten hose clamps at y-pipe.
  • Re-install front engine cover.

  • Start the car, and check that the engine is running smoothly with no check engine lights.

Figure 14. E55 ignition coil.

Pro Tip

It is recommended that dielectric grease be applied from the coil to spark plug connections to prevent corrosion as well as promote good continuity.

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