Audi A4 S4 B6 B7 4.2 V8 Petrol Engine Ignition Coil 077905115T

Audi A4 S4 B6 B7 4.2 V8 Petrol Engine Ignition Coil is an ignition system component designed for 4.2 V8 petrol engines in Audi A4 and S4 models of the B6 and B7 generations. It ensures the precise generation of the high voltage required for proper ignition of the fuel mixture, which translates into stable engine operation, smooth idle, and correct throttle response.

Specifications and technical data

• SKU: 077905115T
• Mark: Audi
• Condition: Used
• OEM Part Number: 077905115T
• Substitutable numbers: 077905115T, 077 905 115 T
• Fuel type: Petrol
• Category: Leaf & Coil Springs

Purpose and function in the 4.2 V8 engine

The presented ignition coil operates within the ignition system of the petrol engine, responsible for generating high voltage for the spark plug in each cylinder's operating cycle. In Audi 4.2 V8 units, spark stability at high RPMs and under load is particularly important, which is why a properly selected coil has a direct impact on:

• even operation of all cylinders,
• smooth acceleration without jerking,
• easy cold and warm starts,
• reduction of misfires and engine control unit errors.

For V8 engines, using the correct type of coil is crucial for the durability of the powertrain and the proper operation of the exhaust system and catalytic converters.

Construction and technical characteristics

The ignition coil in this application is a component adapted to work with the ignition control system in an Audi petrol engine. The design allows for mounting directly onto the spark plug, which minimizes energy loss and improves spark quality. The use of appropriately selected insulating materials and windings allows for operation in the high temperatures of the engine bay and under variable loads.

The component has been designed to work with the factory Audi engine control unit, ensuring that the correct coil charging time characteristics and spark energy are maintained. Proper matching of electrical parameters reduces the risk of overloading both the coil itself and the control unit.

Benefits of using a dedicated ignition coil

Using an ignition coil designed for the 4.2 V8 engine in the Audi A4/S4 B6/B7 allows for maintaining the factory performance parameters of the powertrain. The most important advantages include:

• stable ignition spark across the full RPM range,
• better idle quality,
• reduced risk of misfires and the engine entering limp mode,
• proper compatibility with the OBD diagnostic system,
• maintenance of factory performance and torque characteristics.

In the case of symptoms such as jerking, power loss, uneven idle, or appearing ignition errors, replacing the coil with a functional unit is one of the basic diagnostic steps.

Component condition and practical application

The offered coil comes from dismantling and is a used component, which allows for an economical repair of the ignition system while maintaining compliance with Audi's factory specifications. This type of part is particularly attractive for 4.2 V8 engines, where the cost of new components can be high, and a well-selected used element can effectively restore the proper operation of the unit.

Before installation, a standard inspection of the ignition system (condition of spark plugs, wiring, grounds) and computer diagnostics are recommended to confirm that the coil is indeed the source of the problem. A properly selected and functional component helps reduce further stress on the exhaust system and catalytic converters resulting from misfires.

System expansion and related components

If you are planning a comprehensive repair or upgrade of the engine area in your Audi and need other elements from the same group, such as additional coils, mounting hardware, or related ignition system components, check the available parts in the Audi leaf springs and blades category.

If you are considering a wider use of parts from dismantling and want to better understand when used components are a good choice, it is worth reading the guide on our blog: The second life of electronics – when is it worth choosing used engine control units, comfort modules, and parking sensors?. You will find practical tips there that help you make informed purchasing decisions for other car components as well.