Removing and installing glow plugs: Audi A8 D3 (AFB, AKE, AKN, ASB, …)

🧭 Before you start

Fits: Audi A8 D3 (4E, 2002–2010)

• Special tools named: torque wrench
• Renewed: relevant ceramic glow plug

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• Before removing the ceramic glow plugs, always detach any ancillary components which restrict access (e.g. upper and lower sections of intake manifold).
• Before installing glow plugs, clean combustion deposits out of glow plug openings in cylinder head.
• IMPORTANT: always observe the precautions listed above.The threads in the cylinder head and on the ceramic glow plugs must be dry, and free of oil and grease. — Screw in ceramic glow plugs finger-tight.
• Reconnect electrical connectors on ceramic glow plugs. Make sure that connector engages properly.
• Erase fault memory of engine control unit. Do not start engine at this stage.

🔧 Engine codes this applies to

🔩 Torque settings

Values can differ between engine variants — check the code stamped on your block.

ℹ️ Always cross-check the exact figure against your vehicle's factory manual before final tightening — a wrong torque can damage the engine. These values are extracted from workshop data and may not cover every variant or revision.

📋 Procedure

1. ⚠ Due to the special properties of the material used, the ceramic glow plugs (Bosch type GSK3) are easily damaged and require extra care when handling and installing.Always install a new ceramic glow plug if you are not sure the old one is in perfect condition.If a ceramic glow plug has been damaged or the heater pin is broken, this will invariably cause engine damage.If the heater pin of the glow plug is broken, the fragments must be removed from the engine before starting for the first time, otherwise this will cause mechanical damage (piston seizure). Remove the relevant cylinder head if necessary. — Before removal, the ceramic glow plugs must be burnt clean using the final control diagnosis function in the diagnostic tester.
2. Clean glow plug openings in cylinder head; make sure no dirt gets into cylinder. [Note: Cleaning procedure:Use a vacuum cleaner to remove coarse dirt.Spray brake cleaner or suitable cleaning agent into glow plug openings, let it work in briefly, and blow out with compressed air.Then clean the glow plug openings using a cloth moistened with oil.]
3. When loosening and tightening ceramic glow plugs, use special tool U/J extension and socket, 10 mm3220 and a suitable torque wrench.
4. Before removing the ceramic glow plugs, always detach any ancillary components which restrict access (e.g. upper and lower sections of intake manifold).
5. Unplug the connector from the glow plug to be removed.

6. When loosening a ceramic glow plug, do not exceed the "“maximum release torque”" of 20 Nm. When loosening, always use U/J extension and socket, 10 mm3220 and a torque wrench. [Note: If the ceramic glow plugs are difficult to remove (release torque more than 20 Nm), use a suitable penetrating oil spray and try again.If one of the ceramic glow plugs cannot be loosened by applying the maximum release torque of 20 Nm, the cylinder head must first be removed 15 so the glow plug can be unscrewed.] — 20 Nm (15 lb-ft)
7. Then unscrew the ceramic glow plug carefully by hand or using a suitable length of hose (approx. 25 cm; Part No. N 020 150 5, sold by the metre). Keep the glow plug straight while unscrewing.
8. Carefully pull ceramic glow plugs out from above using a suitable tool (such as a length of hose). Take care to prevent glow plugs from contacting other parts. [Note: Before installing glow plugs, clean combustion deposits out of glow plug openings in cylinder head.]
9. ⚠ IMPORTANT: always observe the precautions listed above.The threads in the cylinder head and on the ceramic glow plugs must be dry, and free of oil and grease. — Screw in ceramic glow plugs finger-tight.
10. Check function of ceramic glow plugs after installation and before starting engine for the first time.
11. If this specification is not obtained (resistance greater than 1 Ohm), remove defective ceramic glow plug again and check whether heater pin is broken. If a broken heater pin is visible, it is very important to remove the fragments from the engine before starting for the first time. Remove cylinder head if necessary, otherwise this will result in mechanical damage to the engine.
12. Reconnect electrical connectors on ceramic glow plugs. Make sure that connector engages properly.
13. Install any ancillary units that were previously detached.
14. Erase fault memory of engine control unit. Do not start engine at this stage.
15. Perform final control diagnosis (automatic glow period control unit J179).
16. Interrogate fault memory again. Do not start engine at this stage.
17. The engine must not be started if the fault memory has registered a fault relating to the ceramic glow plugs. Check electrical connectors and renew relevant ceramic glow plug if necessary.
18. ⚠ Mixed installation of ceramic glow plugs and metal glow plugs on the same engine is not permissible. — Switch off ignition.
19. Detach glow plug connectors from glow plugs which are to be removed.
20. Clean glow plug openings in cylinder head; make sure no dirt gets into cylinder. [Note: Cleaning procedure:Use a vacuum cleaner to remove coarse dirt.Spray brake cleaner or suitable cleaning agent into glow plug apertures, let it work in briefly, and blow out with compressed air.Then clean the glow plug openings using a cloth moistened with oil.]
21. Before removal, always detach any ancillary components which restrict access.
22. To slacken the glow plugs use special tool U/J extension and socket, 10 mm3220
23. Before installing glow plugs, clean out combustion deposits from glow plug bores in cylinder head.
24. To tighten the glow plugs use special tool U/J extension and socket, 10 mm3220 with a suitable torque wrench.
25. Tighten glow plugs.
26. ⚠ If the ceramic glow plugs (Bosch) have been replaced with metal glow plugs (Beru) the software of the engine control unit must be flashed accordingly before connecting the glow plug connectors. If this is not done, the metal glow plugs will be IRREPARABLY DAMAGED when the ignition is switched on. — Attach glow plug connectors correctly and make sure they are securely fitted.
27. Install any ancillary units that were previously detached.

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