Ignition Coils - All

Complete replacement of all 12 ignition coils on the M275 6.0L BiTurbo V12 engine, including removal of engine covers and access components.

Warnings

Tools required

Parts

• Ignition coil × 12 — Use OEM Mercedes-Benz specification A0001587803
• Spark plug × 12 — Use OEM Mercedes-Benz specification (replace if needed)
• Engine cover grommets — Inspect and replace if damaged

Preparation

1. Park vehicle on level surface and engage parking brake
2. Turn ignition off and remove key
3. Allow engine to cool completely for at least 2 hours
4. Open hood and secure with prop rod
5. Disconnect negative battery terminal and wait 5 minutes for system discharge

Procedure

1. 1

   Remove engine covers
   Remove the upper engine cover by releasing the quick-release fasteners. Remove the T30 Torx screws securing the left and right side acoustic engine covers. Lift covers carefully to avoid damaging grommets. Set covers aside in clean area.
   Torque spec

   Cover Screws15 Nm (11 lb-ft)
2. 2

   Remove air intake components
   Disconnect the mass airflow sensor electrical connectors on both intake tracts. Loosen hose clamps on air filter housings. Remove air filter housings and intake ducts to gain access to the rear cylinders. Set components aside carefully to avoid sensor damage.
3. 3

   Disconnect ignition coil connectors - Right bank (cylinders 1-6)
   Locate ignition coils on right bank (passenger side). Press release tab on each coil electrical connector and disconnect. Work from front to rear: cylinders 1, 2, 3, 4, 5, 6. Use gentle rocking motion if connectors are tight - do not force.
   ⚠Electrical connectors may be brittle - apply gentle pressure to release tabs to avoid breaking
4. 4

   Remove ignition coils - Right bank
   Remove the single bolt securing each ignition coil using 10mm socket. Pull coils straight up with slight twisting motion to break seal. If coil is stuck, gently rock side-to-side - never pry against engine components. Inspect coil boots for cracks or oil contamination.
   Torque spec

   Ignition Coil Bolts8 Nm (6 lb-ft)
5. 5

   Disconnect ignition coil connectors - Left bank (cylinders 7-12)
   Locate ignition coils on left bank (driver side). Press release tab on each coil electrical connector and disconnect. Work from front to rear: cylinders 7, 8, 9, 10, 11, 12. Access to rear cylinders is tighter - may require working from underneath or side.
   ⚠Electrical connectors may be brittle - apply gentle pressure to release tabs to avoid breaking
6. 6

   Remove ignition coils - Left bank
   Remove the single bolt securing each ignition coil using 10mm socket. Pull coils straight up with slight twisting motion to break seal. Left bank access is more restricted - use 6-inch extension for rear cylinders. Inspect coil boots for cracks or oil contamination.
   Torque spec

   Ignition Coil Bolts8 Nm (6 lb-ft)
7. 7

   Clean spark plug wells
   Use compressed air to blow out debris from all 12 spark plug wells before proceeding. Remove any oil or moisture with clean shop towels. Inspect wells for signs of oil leakage from valve cover gaskets. Ensure wells are completely clean and dry before spark plug removal.
   ⚠Oil or debris in spark plug wells can fall into cylinders during plug removal - clean thoroughly
8. 8

   Remove and inspect spark plugs (if replacing)
   If replacing spark plugs, use spark plug socket with extension to remove all 12 plugs. Turn counterclockwise carefully. Inspect old plugs for wear patterns, carbon buildup, or oil fouling. Check gap on new plugs before installation - should be within Mercedes-Benz specification (typically 0.8-0.9mm for this engine).
   ⚠️Apply anti-seize compound to spark plug threads before installation - critical for aluminum heads to prevent seizure
   Torque spec

   Spark Plugs - Aluminum Head20 Nm (15 lb-ft)
9. 9

   Install new spark plugs (if replacing)
   Apply thin coat of anti-seize compound to spark plug threads, avoiding electrode area. Thread plugs by hand to avoid cross-threading. Once seated, torque to specification using torque wrench. Install all 12 plugs following proper sequence. Do not overtighten.
   ⚠️Do not exceed torque specification - aluminum cylinder heads are easily damaged by overtightening
   Torque spec

   Spark Plugs - Aluminum Head20 Nm (15 lb-ft)
10. 10

    Prepare new ignition coils
    Remove new ignition coils from packaging. Apply thin coat of dielectric grease to inside of coil boots where they contact spark plugs. This prevents moisture intrusion and aids future removal. Inspect each coil for damage before installation.
11. 11

    Install new ignition coils - Right bank
    Insert new ignition coils into wells on right bank (cylinders 1-6), ensuring coils seat fully onto spark plugs with firm downward pressure. Install and hand-tighten mounting bolts, then torque to specification. Reconnect electrical connectors - listen for positive click.
    Torque spec

    Ignition Coil Bolts8 Nm (6 lb-ft)
12. 12

    Install new ignition coils - Left bank
    Insert new ignition coils into wells on left bank (cylinders 7-12), ensuring coils seat fully onto spark plugs with firm downward pressure. Install and hand-tighten mounting bolts, then torque to specification. Reconnect electrical connectors - listen for positive click. Verify all connections are secure.
    Torque spec

    Ignition Coil Bolts8 Nm (6 lb-ft)
13. 13

    Reinstall air intake components
    Reinstall air filter housings and intake ducts. Tighten hose clamps securely. Reconnect mass airflow sensor electrical connectors on both sides. Ensure all connections are secure and hoses are properly seated.
14. 14

    Reinstall engine covers
    Inspect engine cover grommets for damage and replace if necessary. Position left and right acoustic covers and secure with T30 Torx screws to specification. Install upper engine cover, ensuring quick-release fasteners engage properly. Verify covers are secure.
    Torque spec

    Cover Screws15 Nm (11 lb-ft)
15. 15

    Reconnect battery and verify installation
    Reconnect negative battery terminal. Turn ignition to ON position without starting (listen for fuel pump priming). Check for warning lights on instrument cluster. Start engine and verify smooth idle with no misfires. Allow engine to reach operating temperature and verify no fault codes are present.

Reassembly

1. Ensure all 12 ignition coil electrical connectors are fully seated and locked
2. Verify all engine covers are properly secured to prevent rattles
3. Double-check that no tools or parts were left in engine bay
4. Clear any fault codes that may have been stored during the procedure

Verification

• Start engine and verify smooth idle with no misfires or hesitation
• Listen for any unusual noises or vibrations during idle and light acceleration
• Use scan tool to verify no active misfire codes (P0300-P0312) are present
• Perform test drive under various loads to confirm proper ignition system operation
• Verify all engine covers are secure and no rattles are present
• Check for proper seating of all coil connectors by visual inspection

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