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Autopapyrus · Audi A6 2.4 V6 BDW (2010)
https://autopapyrus.com/guides/audi/a6/spark-plug-replacement/
Compiled automatically from service literature and owner experience. Specs are for the typical configuration — check them against your exact car before you start.

Audi A6 2.4 V6 BDW (2010): Spark Plug Replacement

The BDW engine has 6 spark plugs, three per cylinder bank, and a separate ignition coil on each plug. The recommended replacement interval is about 60,000 km (37,000 miles). The front bank is easy to reach. The rear bank sits against the firewall and is partly covered by the intake tract and hoses, so most of the time goes into it.

Difficulty: Medium Time: 1.5-3 hours Steps: 10 Tools: 16 mm spark plug socket with rubber insert or magnet, extension and universal joint, torque wrench, screwdrivers (flat-blade and Torx), coil puller or long screwdriver, compressed air or shop vacuum, copper or ceramic anti-seize thread lubricant (optional, in a very thin layer), hose clamp pliers

Part

  • 🔩 6 spark plugs for the 2.4 V6 engine (M14x1.25 thread, 16 mm hex, gap about 0.9 mm). NGK, Champion, Denso, Beru and similar plugs are suitable when the catalog lists them for the BDW. The OE part number is not given here to avoid errors, so buy by catalog lookup for your engine. Also, if needed, coil seal rings or rubber coil boots
There's a full repair manual for this car Every system, wiring diagrams and torque specs — not just this job. Haynes AutoFix (online) and 3 more. See manuals →

Step by step

10 steps
  1. Work on a cold engine. Disconnect the negative battery terminal and remove the decorative plastic engine cover. It is held by six to ten fasteners that release with a quarter turn using a flat-blade screwdriver.
  2. Disconnect the air ducts and crankcase ventilation hoses that are in the way by carefully releasing the clips. Plastic at this age is brittle, so do not pull on it with force. If a hose blocks access to the spark plugs, you will have to remove it temporarily. Remember or photograph the routing of all hoses.
  3. Start with the front bank (the three cylinders closest to the radiator). First disconnect the connector from each coil by pressing the lock. Then remove the coil mounting bolt, if there is one. Pull the coil straight up, rocking it gently along its axis. Do not pull on the wire.
  4. Blow out the spark plug wells with compressed air or clean out the dirt with a vacuum so that debris does not fall into the cylinder. Unscrew the plug with the 16 mm socket, keeping the socket exactly in line with the well axis.
  5. Inspect the old spark plugs. The color of the deposits, oil on the threads, or an oily well will tell you about the condition of the engine. Oil in the wells indicates worn valve cover seals or gaskets.
  6. Check the gap on the new plugs (about 0.9 mm) with a feeler gauge. Do not bend the electrode sharply, especially on plugs with thin iridium or platinum electrodes. Buy plugs that come pre-gapped from the factory and adjust them only if the gap is clearly off.
  7. Thread the new plugs in by hand until snug, so you do not strip the threads in the aluminum head. Then tighten with a torque wrench to about 25 N·m (18 lb-ft). If the packaging specifies a different value, follow the packaging.
  8. Before installing the coils, inspect them and the rubber boots. Cracks and signs of arcing (dark tracks) mean the coil must be replaced. Install the coils, secure the mounting bolts and connect the connectors until they click.
  9. For the rear bank (against the firewall), remove everything that blocks access: air ducts, wiring clips and, if necessary, hose brackets. Then repeat steps 3-8 for the remaining three cylinders. If you cannot get access, use a universal joint and a long extension, but it is better to remove the obstruction whenever possible.
  10. Reinstall all hoses and ducts and the engine cover, then reconnect the battery. Start the engine, check that the idle is smooth, and make sure there are no warning lights on the instrument cluster and no air leaks (hissing, fluctuating RPM).

Common mistakes and warnings

  • Do not use excessive force when unscrewing the spark plugs. If a plug is tight, turn it back in slightly, apply penetrating oil and try again, so you do not strip the threads in the head. Do not let dirt get into the cylinders. Do not overtighten the plugs: the aluminum head is easily damaged. Check the exact torque values and the steps for removing intake parts against the manufacturer's specifications, since the design of the rear of the engine can vary by trim and equipment.