Valve Train Overview

WARNING: This page is about a different variant/trim than selected.

CAUTION:

Risk of damaging valves and piston heads after working on valve train.

The motor must not be started for about 30 minutes after Installation camshafts because the hydraulic equalization elements must seat themselves.
To ensure valves do not strike pistons when starting, carefully rotate engine at least 2 full revolutions.

NOTE:

The illustration shows the cylinder bank 2 cylinder head (left).

Fig 1: Identifying Valvetrain Overview

Courtesy of AUDI OF AMERICA, LLC

Valve
- Do not rework, only grinding is permitted.
- Mark the installed position for installation later.
- Checking. Refer to VALVES, CHECKING .
- Valve dimensions. Refer to VALVE DIMENSIONS .
Cylinder Head
- Valve Guides, Checking. Refer to VALVE GUIDES, CHECKING .
- The valve seat may not reworked due to a close tolerances.
Valve Stem Seal
- Replacing: With cylinder head installed, refer to VALVE STEM SEALS, CYLINDER HEAD INSTALLED, REMOVING AND INSTALLING . With cylinder head removed, refer to VALVE STEM SEALS, REMOVING AND INSTALLING WITH CYLINDER HEAD REMOVED .
Valve Spring
Valve Spring Retainer
Valve Keepers
Camshaft Seal
- Replacing. Refer to CAMSHAFT SEAL, REMOVING AND INSTALLING .
Bolt
- Tightening specification and sequence: left cylinder head, refer to Fig 2, right cylinder head Fig 3
Nut
- Tightening specification and sequence: left cylinder head Fig 2, right cylinder head Fig 3.
Guide Frame
- With integrated camshaft bearings.
- Removing and Installing: left cylinder head, refer to LEFT CYLINDER HEAD CAMSHAFT, REMOVING AND INSTALLING , right cylinder head, refer to RIGHT CYLINDER HEAD CAMSHAFT, REMOVING AND INSTALLING .
Intake Camshaft
- Removing and Installing: left cylinder head, refer to LEFT CYLINDER HEAD CAMSHAFT, REMOVING AND INSTALLING , right cylinder head, refer to RIGHT CYLINDER HEAD CAMSHAFT, REMOVING AND INSTALLING .
- Axial Play, Measuring. Refer to CAMSHAFT, MEASURING AXIAL CLEARANCE .
- Radial Play, Measuring. Refer to CAMSHAFT, MEASURING RADIAL CLEARANCE .
- Maximum run-out: 0.01 mm
Exhaust Camshaft
- Removing and Installing: left cylinder head, refer to LEFT CYLINDER HEAD CAMSHAFT, REMOVING AND INSTALLING , right cylinder head, refer to RIGHT CYLINDER HEAD CAMSHAFT, REMOVING AND INSTALLING .
- Axial Play, Measuring. Refer to CAMSHAFT, MEASURING AXIAL CLEARANCE .
- Radial Play, Measuring. Refer to CAMSHAFT, MEASURING RADIAL CLEARANCE .
- Maximum run-out: 0.01 mm
Roller Rocker Lever
- Removing and Installing: left cylinder head, refer to LEFT CYLINDER HEAD CAMSHAFT, REMOVING AND INSTALLING , right cylinder head, refer to RIGHT CYLINDER HEAD CAMSHAFT, REMOVING AND INSTALLING .
- Mark the installed position for installation later.
- Check roller for easy movement.
- Lubricate the running surfaces before Installation.
Hydraulic Adjusting Element
- Mark the installed position for installation later.
- Checking. Refer to HYDRAULIC ADJUSTING ELEMENTS, CHECKING .
- Lubricate the running surfaces before Installation.
Pressure Relief Valve 1.0 Bar
- For the lubricating points in the cylinder head.
- 25 Nm

Fig 2: Identifying Left Cylinder Head Guide Frame, Tightening Specifications and Sequence

Courtesy of AUDI OF AMERICA, LLC

-- Tighten the bolts and nuts in 2 steps in the sequence shown:

Stage	Bolts/Nuts	Tightening Specification
1.	-1 to 18-	Install all the way in by hand. The guide frame must touch the entire contact surface on the cylinder head.
2.	-1 to 18-	9 Nm

Fig 3: Identifying Right Cylinder Head Guide Frame, Tightening Specifications and Sequence

Courtesy of AUDI OF AMERICA, LLC

-- Tighten the bolts and nuts in 2 steps in the sequence shown:

Stage	Bolts/Nuts	Tightening Specification
1.	-1 to 17-	Install all the way in by hand. The guide frame must touch the entire contact surface on the cylinder head.
2.	-1 to 17-	9 Nm