Table of contents: 4-cylinder, two-valve ALZ engine… ↓ 4-cylinder, 5-valve AVJ engine with… ↓ 4-cylinder, 5-valve ALT engine with… ↓ 6-cylinder, 5-valve ASN engine with… ↓ 6-cylinder, 5-valve ASN engine with… ↓
In its maintenance plan, Audi recommends replacing spark plugs only after 60,000 km. As a rule, spark plugs withstand this interval without problems. However, if the engine starts poorly or jerks after starting, the cause may be in the spark plugs. Invisible cracks in the ceramic insulator during cold engine starting are filled with condensing fuel, which takes energy from the ignition spark. If you think that the spark plugs are not working as they should, replace them to be sure.
The spark plugs are replaced when the engine is cold, because if the spark plugs are removed when the engine is hot, the thread under the spark plug in the cylinder head, which is made of light metal, may break. To remove the spark plugs, you will need a 16 mm spark plug wrench (HAZET 900AKF; HAZET 2506 or HAZET 4766-1; in Audi workshops, they use the 3122B spark plug wrench). When removing spark plug tips, it is convenient to use the special HAZET 1849 pliers (3277 A).
4-cylinder, two-valve ALZ engine with a working volume of 1.6 l
1. Remove the engine cover.
2. With the ignition off, remove the spark plug tips 1.
Spark plugs in the ALZ engine
3. Remove the spark plugs with the 3122B key (or a similar spark plug wrench).
4. Screw in new spark plugs (30 Nm).
5. Check the tight fit of the high-voltage wires and spark plug tips.
6. If the engine is controlled by the Simos 3.4 control unit, check the sequence in which the high-voltage wires are connected to the ignition coil. If the wire is changed, it must be excluded that the new wire is connected incorrectly. In view of the above, pay attention to the connection of the wires to the ignition coil outputs (see picture).
Ignition coil for ALZ engine: output A on coil for cylinder 1, output B on coil for cylinder 2, output C on coil for cylinder 3, output D on coil for cylinder 4.
4-cylinder, 5-valve AVJ engine with a working volume of 1.8 liters
1. Remove the engine cover.
Spark plugs in the AVJ engine
2. With the ignition off, remove connectors 1 from the ignition coils.
3. Using a plastic wedge, separate the coils from the spark plugs.
4. Remove the spark plugs with the 3122B key (or a similar spark plug wrench).
5. Screw in new spark plugs (30 Nm).
6. Install the ignition coils; to do this, the coils need to be turned slightly so that they engage.
4-cylinder, 5-valve ALT engine with a working volume of 2.0 liters
1. Remove the engine cover.
2. Unscrew both screws 1 and, with the ignition off, remove connectors 2 from the ignition coils.
Spark plugs in the ALT engine
3. Using a plastic wedge, separate the coils from the spark plugs.
4. Remove the spark plugs with the 3122B key (or a similar spark plug wrench).
5. Screw in new spark plugs (30 Nm).
6. Install the ignition coils; to do this, the coils need to be turned slightly so that they engage.
6-cylinder, 5-valve ASN engine with a working volume of 3.0 liters (right bank of cylinders)
1. Turn off the ignition and remove the engine cover. Remove the upper part of the air filter housing.
2. Unscrew both screws 1 and remove connectors 2 from the ignition coils.
Spark plugs in ASN engine (right bank of cylinders)
3. Using a plastic wedge, separate coils 3 from the spark plugs.
4. Remove the spark plugs with the 3122B key (or a similar spark plug wrench).
5. Screw in new spark plugs (30 Nm).
6. Install the ignition coils; to do this, the coils need to be turned slightly so that they engage.
6-cylinder, 5-valve ASN engine with a working volume of 3.0 liters (left bank of cylinders)
1. Turn off the ignition and remove the engine cover. Remove the upper part of the air filter housing. Unscrew the expansion tank of the cooling system (arrow in the top picture), tie the tank together with the hoses attached to it somewhere to the side (1, 2 and 3).
Removing the expansion tank of the cooling system (aSN engine)
2. Remove both screws 1 (see picture below) and remove the connectors 2 from the ignition coils (see picture below).
3. Using a plastic wedge, separate coils 3 from the spark plugs (see picture below).
Spark plugs in ASN engine (left bank of cylinders)
4. Remove the spark plugs with the 3122B key (or a similar spark plug wrench).
5. Screw in new spark plugs (30 Nm).
6. Install the ignition coils, to do this the coils need to be turned a little, they should engage 8 times.
(The original version is on the portal AUDImanual.ru)