Ignition Coil and Iridium Spark Plugs for BMW Z4 (2007-2010) 2.5L

Direct-Fit Ignition Coil and Iridium Spark Plug Service Kit for 2007-2010 BMW Z4

What it Does: Restores high-voltage secondary ignition output and precise combustion timing to resolve misfires, rough idle, and unburned hydrocarbon emissions on naturally aspirated 2.5L inline-six engines.

The Stock Z4 Ignition Breakdown and Thermal Fatigue

Factory coil packs situated deep inside the N52 cylinder head are subjected to continuous thermal cycling and valve cover radiant heat soak. Over time, internal epoxy insulation breaks down and primary copper windings develop microscopic dielectric fractures. This leads to secondary voltage leakage, degraded spark energy under high cylinder pressure, uneven flame front propagation, and inevitable DME misfire fault codes (such as 29CD through 29D2).

The Engineering Solution

This comprehensive refresh kit pairs six coil-on-plug units with fine-wire iridium spark plugs. The ignition coils feature premium reinforced copper windings and heat-resistant silicone boots designed to withstand high under-hood temperatures without dielectric breakdown. The matched iridium plugs deliver a low-voltage firing threshold, concentrated spark discharge, and robust resistance to carbon fouling, guaranteeing stable idle stability and peak thermodynamic efficiency across the entire RPM band.

Technical Specifications

Compatibility

• 2007-2008 BMW Z4 (E85 Roadster / E86 Coupe): 2.5L N52 Inline-6
• 2009-2010 BMW Z4 (E89 Roadster): sDrive23i 2.5L N52 Inline-6

The BMW Precision Caliber

Engineered to meet exact Bavarian DME signal tolerances, this direct-replacement ignition assembly ensures zero diagnostic trouble codes, smooth throttle modulation, and OEM-spec dwell times without requiring ECU adaptation resets.