Ignition Coil + Spark Plugs for Mercedes Benz M-Class (2003-2005) 3.7L

OEM-Grade Direct-Fit Ignition Kit for 2003-2005 Mercedes Benz M-Class

What it Does: The Ignition Coil and Spark Plug Kit replaces degraded factory secondary ignition components on the 2003-2005 Mercedes Benz M-Class to eliminate cylinder misfires, restore clean combustion, and stabilize idle quality.

The Stock Mercedes Benz M-Class Secondary Ignition Degradation

Under-hood heat soak in the W163 engine bay causes chronic thermal fatigue to the factory ignition components of the 3.7L M112 V6. Over time, the internal epoxy resin and secondary copper windings within the factory coils break down, causing dielectric breakdown and voltage flashover. Compounding this issue, the twin-spark architecture demands reliable firing across twelve electrode gaps; worn plugs increase overall electrical resistance, overloading the coils and causing P0300 through P0306 misfire codes, hesitations under load, unburnt hydrocarbon wash, and catalytic converter damage.

The Engineering Solution

This comprehensive service kit restores ignition efficiency by matching six direct-fit coils with twelve calibrated spark plugs. Each ignition coil is built with high-dielectric epoxy potting, insulated copper windings, and high-temp PBT housings resistant to thermal arc tracking and micro-cracking. Paired with corrosion-resistant, pre-gapped spark plugs featuring dense alumina ceramic insulators, this setup ensures a rapid spark discharge across both flame fronts in each M112 cylinder chamber. The result is complete fuel atomization, prompt throttle response, and dependable cold-weather starting without electrical leakage.

Technical Specifications

Compatibility

• 2003 Mercedes-Benz M-Class ML350 3.7L V6 (W163, M112.970 Engine)
• 2004 Mercedes-Benz M-Class ML350 3.7L V6 (W163, M112.970 Engine)
• 2005 Mercedes-Benz M-Class ML350 3.7L V6 (W163, M112.970 Engine)

Frequently Asked Questions

Does this fit the W163 M-Class?
Yes, this is a direct fit for the 2003-2005 Mercedes Benz M-Class equipped with the M112 3.7L V6 engine.

Are spark plug wires included with this kit?
No, this kit includes 6 coils and 12 spark plugs; reuse your existing secondary ignition leads or replace them separately if inspecting shows boot deterioration.

The Mercedes Benz Precision Standard

Engineered to exact European OBD-II operational parameters, this ignition kit delivers factory-level resistance matching to maintain optimal primary current and prevent CEL fault codes while safeguarding your catalytic converters from rich-condition thermal degradation.