Preparation

• Gather tools such as a ratchet set with an extension, spark plug socket, and a torque wrench.
• Purchase the correct replacement spark plugs for the 2017 Audi A4.
• Make sure the engine is cool before beginning any work.

Disconnect the Battery

• Locate the car battery and use a wrench to disconnect the negative terminal. This will prevent any accidental electrical shocks while you’re working on the vehicle.

Remove the Engine Cover

• Carefully detach the plastic engine cover if your Audi A4 has one. This often involves gently pulling upwards until the cover pops free. Set it aside to access the coil packs.

Locate the Coil Packs

• Identify the coil packs, which are located on the engine's cylinder head. The Audi A4 typically has these located above the spark plugs.

Disconnect the Coil Pack Connectors

• Carefully unplug the electrical connectors from each coil pack. These may have a tab that needs to be pressed before they can be pulled off.

Remove the Coil Packs

• Using the appropriate tool, remove the screws or bolts that secure each coil pack. Gently pull the coil packs out and set them aside, being cautious not to damage them.

Remove the Old Spark Plugs

• Insert the spark plug socket and extension into the spark plug well.
• Carefully turn counter-clockwise to remove the old spark plug. Ensure you are gentle to avoid damaging the threads.
• Repeat the process for each spark plug.

Install the New Spark Plugs

• Inspect the new spark plugs for damage and make sure they match the ones you have removed.
• Using your hand, gently thread the new spark plug into the cylinder head to avoid cross-threading.
• Once it’s hand-tight, use a torque wrench to tighten the spark plug to the manufacturer’s specifications (usually around 20-25 Nm for many vehicles, but check your manual for specifics).

Reinstall the Coil Packs

• Carefully place each coil pack back onto the spark plugs, pressing down until they sit snugly.
• Secure the coil packs by re-installing the screws or bolts that were previously removed.

Reconnect the Coil Pack Connectors

• Reattach the electrical connectors to each coil pack, ensuring they are clipped back into place securely.

Reinstall the Engine Cover

• If an engine cover was removed, align it properly and press it down until it snaps back into place.

Reconnect the Battery

• Finally, reattach the negative terminal to the battery and tighten the connector securely.

Test the Vehicle

• Start the engine to ensure that it runs smoothly, which indicates the spark plugs are functioning correctly.
• Take the car for a short drive to confirm there are no misfires or unusual sounds.

Following these detailed steps will help ensure that the spark plugs on your 2017 Audi A4 are successfully changed.