Symptoms
Misfire codes, rough idle, hesitation under boost. Many owners don't know when the plugs were last done.
The fix, step by step
- Replace all 16 plugs (the M113 has twin plugs per cylinder) and inspect the wires and coil packs.
- VRP suggests heavier-insulated wires if the originals are tired.
- Fix any misfire before adding power.
Tools & part numbers
- Spark plug socket and extensions
- dielectric grease
- plugs
- wires
- coils if needed
Where to buy the parts
NGK ILFR6A spark plug (G 55 Kompressor, need 16)FCP Euro ↗Amazon ↗
Bosch FR8DPP33 spark plugs, set of 16FCP Euro ↗Amazon ↗
Bremi ignition wire set 112 150 00FCP Euro ↗Amazon ↗
Genuine Mercedes ignition coil 000 158 78 03FCP Euro ↗Amazon ↗
Hunting a used or discontinued part? Search eBay Motors for Mercedes-Benz G 55 AMG parts →
Rated for a competent home mechanic with a decent tool kit. Confirm torque figures, fluids and procedures against the factory service manual for your VIN, support the truck on stands rather than a jack, and work at your own risk (disclaimer). Some parts links are affiliate links, which pay us a small commission at no cost to you.