Ignition Coil + Iridium Spark Plugs for Mercedes Benz SLK-Class (2012-2016) 5.5L

Direct-Fit Ignition Coil and Spark Plug Tune-Up Kit for 2012-2016 Mercedes Benz SLK-Class 5.5L (R172 / M152)

What it Does: The Ignition Coil + Iridium Spark Plugs kit restores secondary ignition voltage and consistent flame kernel propagation on the 2012-2016 Mercedes Benz SLK55 AMG to eliminate cylinder misfires and erratic idle under load.

The Stock Mercedes Benz SLK-Class Thermal Degradation and Secondary Breakdown

In the tightly packaged engine bay of the R172 chassis, the naturally aspirated M152 5.5L V8 operates under extreme thermal soak. Over time, internal epoxy insulation and primary copper windings within factory coil packs degrade, leading to dielectric breakdown and micro-arcing. Simultaneously, cylinder deactivation cycles (AMG Cylinder Management) cause uneven electrode erosion and carbon deposits across OEM plugs, broadening the spark gap beyond factory tolerance. This increased resistance forces degraded coils to demand higher dwell energy, causing high-RPM spark blowout, rough running, and stored pending DTC misfire codes.

The Engineering Solution

This service kit replaces all eight coil-on-plug units and plugs with matched OE-specification components. The ignition coils feature high-temp magnetic cores and reinforced PBT thermoplastic housings resistant to dielectric breakdown. Matched with double iridium Bosch ZR6SII3320 spark plugs, the fine-wire center electrode lowers the required ionization voltage, ensuring clean direct-injection combustion across both 4-cylinder eco-mode and full 8-cylinder dynamic operation under 12.6:1 compression.

Technical Specifications

Compatibility

• 2012 Mercedes Benz SLK-Class SLK55 AMG 5.5L V8 (M152.980)
• 2013 Mercedes Benz SLK-Class SLK55 AMG 5.5L V8 (M152.980)
• 2014 Mercedes Benz SLK-Class SLK55 AMG 5.5L V8 (M152.980)
• 2015 Mercedes Benz SLK-Class SLK55 AMG 5.5L V8 (M152.980)
• 2016 Mercedes Benz SLK-Class SLK55 AMG 5.5L V8 (M152.980)

Frequently Asked Questions

Does this fit the R172 SLK-Class?
Yes, this is a direct fit for the 2012-2016 Mercedes Benz SLK-Class equipped with the M152 engine.

Do these spark plugs require manual gapping prior to installation?
No, the double iridium plugs are pre-gapped to OEM specification for the M152 direct-injection cylinder head; verify gap visually and do not alter the delicate fine-wire tip.

The Mercedes Benz Precision Standard

European direct-injection engines require precise secondary voltage to preserve ECU calibration and prevent catalytic converter fouling. This kit guarantees clean combustion, stable ignition timing, and zero check engine lights across the full RPM range.