{"product_id":"ignition-coil-and-iridium-spark-plugs-for-bmw-z4-2003-2005-2-5l","title":"Ignition Coil and Iridium Spark Plugs for BMW Z4 (2003-2005) 2.5L","description":"\u003ch2\u003eDirect-Fit Ignition Refresh Kit for 2003-2005 BMW Z4\u003c\/h2\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhat it Does:\u003c\/strong\u003e Restores factory secondary ignition performance by replacing degraded coils and spark plugs to eliminate misfires, rough idle, and unburned fuel waste in 6-cylinder applications.\u003c\/p\u003e\n\n\u003ch3\u003eThe Stock Z4 Thermal Degradation Failure Point\u003c\/h3\u003e\n\u003cp\u003eThe M54 engine bay subjects coil-on-plug modules to continuous high-temperature thermal cycling. Over time, factory coil insulation breaks down, causing internal dielectric breakdown and secondary resistance drift. Simultaneously, standard plug electrode erosion widens the spark gap, increasing the kilovolt demand on aging secondary windings. This typically manifests under heavy load as intermittent misfires (OBD-II codes P0300–P0306), degraded throttle response, and rough cold-start idle.\u003c\/p\u003e\n\n\u003ch3\u003eThe Engineering Solution\u003c\/h3\u003e\n\u003cp\u003eThis comprehensive ignition service kit features 6 heavy-duty ignition coils paired with 6 premium iridium-tipped spark plugs. The coil assemblies are engineered with high-purity internal copper windings and direct-fit, weather-sealed blade terminals that resist thermal fatigue and dielectric leakage. The fine-wire iridium spark plugs lower the required ionization voltage, ensuring crisp arc transfer, complete flame kernel propagation, and clean combustion across the M54 powerband.\u003c\/p\u003e\n\n\u003ch3\u003eTechnical Specifications\u003c\/h3\u003e\n\u003ctable width=\"100%\" style=\"border-collapse: collapse; border: 1px solid #e0e0e0; font-size: 14px;\"\u003e\n  \u003ctr style=\"background-color: #f9f9f9;\"\u003e\n\u003ctd style=\"padding:8px;\"\u003e\u003cstrong\u003eFitment\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding:8px;\"\u003e2003-2005 BMW Z4\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003ctd style=\"padding:8px;\"\u003e\u003cstrong\u003eEngine \/ Chassis\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding:8px;\"\u003eM54B25 \/ E85\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr style=\"background-color: #f9f9f9;\"\u003e\n\u003ctd style=\"padding:8px;\"\u003e\u003cstrong\u003eStock Output\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding:8px;\"\u003e184 hp \/ 175 lb-ft (Approx)\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003ctd style=\"padding:8px;\"\u003e\u003cstrong\u003ePart Number \/ Interchange\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding:8px;\"\u003eUF515, UF-515, UF522, UF-522\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/table\u003e\n\n\u003ch3\u003eCompatibility\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003e2003 BMW Z4 2.5i Roadster (2.5L L6 M54B25)\u003c\/li\u003e\n  \u003cli\u003e2004 BMW Z4 2.5i Roadster (2.5L L6 M54B25)\u003c\/li\u003e\n  \u003cli\u003e2005 BMW Z4 2.5i Roadster (2.5L L6 M54B25)\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eThe BMW Precision Standard\u003c\/h3\u003e\n\u003cp\u003eEngineered to exact DME signal parameters, this ignition kit maintains closed-loop factory tolerances, preventing erratic spark timing and avoiding check engine light illumination on European diagnostic systems.\u003c\/p\u003e","brand":"VelocityMax","offers":[{"title":"Default Title","offer_id":50451973505272,"sku":"DS-ERFNDA9QZ","price":101.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0800\/1290\/2648\/files\/ignition-coil-and-iridium-spark-plugs-for-bmw-z4-2003-2005-2-5l-1.jpg?v=1788715557","url":"https:\/\/performancechiptuning.com\/fr\/products\/ignition-coil-and-iridium-spark-plugs-for-bmw-z4-2003-2005-2-5l","provider":"Performance Chip Tuning","version":"1.0","type":"link"}