Ignition Coil + Iridium Spark Plugs for Mercedes Benz GLE-Class GLS-Class (2017) 4.7L 5.5L

Direct-Fit Ignition Coil & Iridium Spark Plug Service Kit for Mercedes Benz GLE-Class, GLS-Class 4.7L, 5.5L (W166/X166 M278/M157)

What it Does: The ignition coil and spark plug kit replaces aged ignition components on the Mercedes-Benz GLE-Class and GLS-Class to restore spark energy, prevent high-load misfires, and ensure clean combustion.

The Stock Mercedes Benz GLE-Class, GLS-Class Ignition Degradation Under Boost

In high-output twin-turbocharged platforms like the M278 and M157, elevated under-hood thermal cycles and cylinder pressures tax the primary and secondary ignition circuits. Over time, factory coil boots harden and crack, causing secondary voltage flashover against the spark plug wells. Concurrently, factory spark plugs experience accelerated center electrode gap widening due to sustained boost, forcing the coils to work beyond their designed insulation limits. This leads to hesitations under wide-open throttle, idle instability, reduced fuel efficiency, and P0300 through P0308 misfire codes.

The Engineering Solution

This comprehensive ignition service kit restores factory dwell efficiency and spark delivery. Engineered as a direct drop-in replacement for OEM reference A2769063700 and UF741, each coil features reinforced copper windings sealed in high-dielectric epoxy to resist heat soak and internal shorting. Paired with Bosch ZR6SII3320 double iridium spark plugs, the laser-welded fine-wire center electrode design lowers the required firing voltage, maintains stable electrode gaps under 20+ psi of boost, and maximizes flame front kernel expansion for total combustion stability.

Technical Specifications

Compatibility

• 2017 Mercedes Benz GLE-Class GLE63 AMG 5.5L V8 Biturbo (M157)
• 2017 Mercedes Benz GLS-Class GLS550 4.7L V8 Biturbo (M278)
• 2017 Mercedes Benz GLS-Class GLS63 AMG 5.5L V8 Biturbo (M157)

Frequently Asked Questions

Does this fit the W166 / X166 GLE-Class, GLS-Class?
Yes, this is a direct fit for the Mercedes Benz GLE-Class and GLS-Class equipped with the M278 4.7L or M157 5.5L Biturbo engine.

What is the proper spark plug installation torque?
Torque these M12 threaded plugs dry to the factory specification of 23 Nm (17 lb-ft); do not apply anti-seize compound.

The Mercedes Benz Precision Standard

High-performance European biturbo powertrains require exact electrical resistance and timing tolerances to prevent ECU torque-intervention and diagnostic faults. This direct-fit kit meets rigid German OE specifications, ensuring clean combustion and factory drivability with zero check engine lights.