Overview - Valve Train

Fig 1: Overview Of Valve Train

Courtesy of AUDI OF AMERICA, LLC

1. Exhaust Valve
   • Do not rework, only lapping is permitted
   • Valve dimensions. Refer to VALVE DIMENSIONS .
   • Valve guides, checking. Refer to VALVE GUIDES, CHECKING .
2. Cylinder Head
3. Valve Guide
   • Checking. Refer to VALVE GUIDES, CHECKING .
4. Valve Stem Seal
   • Replacing: cylinder head installed. Refer to VALVE STEM SEALS, REMOVING AND INSTALLING, CYLINDER HEAD INSTALLED , cylinder head removed. Refer to VALVE SHAFT SEALS, REMOVING AND INSTALLING, CYLINDER REMOVED 
5. Valve Spring
6. Valve Spring Retainer
7. Valve Retainers
8. Hydraulic Adjusting Element
   • With roller rocker lever
   • Do not interchange
   • Lubricate contact surface
9. Exhaust Camshaft
   • Removing and installing. Refer to CAMSHAFT, REMOVING AND INSTALLING .
   • Check radial clearance using Plastigage® (roller rocker lever removed)
   • Radial clearance: 0.024 to 0.066 mm
   • Run-out: maximum 0.04 mm
10. Spring
    • No replacement part
11. Ball
    • For sliding bar
    • Installing. Refer to SLIDING BAR BALL, INSTALLING .
12. Cylinder Head Cover
    • With integrated camshaft bearings
    • Clean sealing surface, reworking is not permitted.
    • Remove old sealant residue.
13. Bolt
    • Replace
    • Loosening. Refer to Fig 2
    • Tightening sequence. Refer to Fig 3
14. O-Ring
    • No replacement part, part of the cam adjustment actuator -15-
    • Coat with engine oil
15. Cam Adjustment Actuator
16. Bolt
    • 5 Nm
17. O-Ring
    • Replace
    • Coat with engine oil
18. Sealing Plugs
19. Intake Camshaft
    • Removing and installing. Refer to CAMSHAFT, REMOVING AND INSTALLING .
    • Check radial clearance using Plastigage® (roller rocker lever removed)
    • Radial clearance: 0.024 to 0.066 mm
    • Run-out: maximum 0.04 mm
20. Cap
    • Replace
    • Removing: with the cylinder head cover installed, pierce through one side of the cover with an awl and pry it out
    • Installing. Refer to INSTALLING  - Drive the cap -1- in without sealant using the Seal Installer - Selector Shaft Oil Seal T10174 (See Figure).
21. Intake Valve
    • Do not rework, only lapping is permitted
    • Valve dimensions. Refer to VALVE DIMENSIONS .
    • Valve guides, checking. Refer to VALVE GUIDES, CHECKING .

Fig 2: Cylinder Head Cover Bolt Loosening Sequence

Courtesy of AUDI OF AMERICA, LLC

-- Loosen the cylinder head cover in the order -1 through 6-.

Fig 3: Cylinder Head Cover Tightening Sequence

Courtesy of AUDI OF AMERICA, LLC

-- Replace the bolts.

-- Hand-tighten bolts in several steps in -1 to 6- sequence.

-- Tighten the bolts in a -1 to 6- sequence to 8 Nm using a torque wrench.

-- Tighten the bolts an additional 90° using a rigid wrench in the sequence -1 to 6-.