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Changing spark plugs on a 1996-2001 A4/S4

Spark plugs, replacing

Spark plugs used on all Audi engines are classified as "long life" by their manufacturers and generally need replacement only during scheduled maintenance services.

Spark plugs are generally pre-gapped by the manufacturer during production but should be checked before installation.

Specification

Spark plugs (AEB, 1.8L engine)

• Gap 0.70 to 0.90 mm (0.029 to 0.035 in)

Spark plugs (ATW, AWM, 1.8L engine)

• Gap 0.80 mm maximum (0.032 in)

Spark Plugs (AFC, ATQ, 2.8L engine)

• Gap 0.90 to 1.10 mm (0.035 to 0.043 in)

Spark Plugs (AHA, 2.8L engine)

• Gap 1.6 mm (0.063 in)

Audi specifies spark plugs made by several different manufacturers and some engines use different heat ranges depending on the model year. Specifications and part numbers can also change. For these reasons, it is advisable to always check with an authorized Audi Dealer's parts department or aftermarket parts specialist for the latest parts information. Spark plug specifications and part numbers may also be found in the applicable Fuel Injection and Ignition section, Repair Group 28.

Spark plug replacement depends on ignition system configuration. Four cylinder engines and some 6-cylinder engines use a system with the ignition coil mounted directly above the spark plug. With this version (individual coils), the coil must first be removed. Earlier 6-cylinder engines use 3 double ended coils mounted at the front of the engine with conventional spark plug wires.

Spark plug replacement, individual coils

Remove sound absorber panel(s) (see illustrations).

Disconnect harness connector (1) from cylinder #1 ignition coil (2). See illustration.

Remove coil securing bolts and ignition coil. If coil is stuck, use a twisting movement to remove.
Remove spark plug with a 5/8 inch (16 mm) spark plug socket and extension or with special tool 3122B.
Replace spark plug.
Reinstall ignition coil and harness connector for cylinder #1.
Repeat procedure for remaining cylinders.
Reinstall sound absorber(s) as required.

Spark plug replacement, double ended coils

Remove sound absorber panel(s) as previously described.
Remove first spark plug wire with a suitable puller. Do not pull directly on wires.
Remove spark plug with a 5/8 inch (16 mm) spark plug socket and extension or with special tool 3122B.
Replace spark plug and reinstall wire.
Repeat procedure for remaining cylinders.
Reinstall sound absorber(s) as required.

Tightening torque

Spark plug to cylinder head (all engines) 30 Nm (22 ft-lb)