Valvetrain Assembly Overview
Valvetrain Assembly Overview
• Cylinder head for bank 2 (left) is shown in illustration.
1 Sealing plug
2 Valve stem seal
• Replacing, refer to --> [ Valve Stem Seals ] Service and Repair.
3 Valve spring
• Installed location, refer to --> [ Installed Position of Valve Spring ]
4 Support element
• With hydraulic valve clearance compensation.
• Clipped into roller rocker lever - item 8 -
• Checking, refer to --> [ Support Element with Hydraulic Adjustment, Checking ] Testing and Inspection.
• Do not interchange.
• Lubricate contact surface.
5 Valve spring plate
6 Valve keys
7 Securing clip
• Check for secure seat.
8 Roller rocker lever
• Do not interchange.
• Check roller for easy movement.
• Lubricate contact surface.
• To assemble, clip onto support element - item 4 - with securing clip - item 7 -.
9 Intake camshaft
• Removing and installing, refer to --> [ Camshaft ] Service and Repair.
• Checking axial play, refer to --> [ Camshaft Axial Clearance, Checking ] Testing and Inspection.
• Check radial clearance using Plastigage (roller rocker lever removed).
• Radial play on bearing -24 mm diameter: 0.024 to 0.066 mm.
• Radial play on bearing -36 mm diameter: 0.032 to 0.078 mm.
• Run out: max. 0.04 mm
10 Gasket
• Replace
11 Bearing bracket
• With integrated camshaft bearings.
• Removing and installing, refer to --> [ Camshaft ] Service and Repair.
12 Bolt, 8 Nm
• Observe tightening sequence, refer to --> [ Camshaft ] Service and Repair.
13 Camshaft Position (CMP) sensor 2 (G163)
14 Bolt, 9 Nm
15 O-ring
• Replace
16 Bolt, 9 Nm
17 CMP sensor 4 (G301)
18 O-ring
• Replace
19 Compression ring
• For camshaft adjuster
20 Exhaust camshaft
• Removing and installing, refer to --> [ Camshaft ] Service and Repair.
• Checking axial play, refer to --> [ Camshaft Axial Clearance, Checking ] Testing and Inspection.
• Check radial clearance using Plastigage (roller rocker lever removed).
• Radial play on bearing -24 mm diameter: 0.024 to 0.066 mm.
• Radial play on bearing -36 mm diameter: 0.032 to 0.078 mm.
• Run out: max. 0.04 mm.
21 Cylinder head
• Check valve guides, refer to --> [ Valve Guide, Checking ] Testing and Inspection.
22 Intake valve
• Do not rework, only lapping is permitted.
• Mark installed position for reinstallation
• Valve dimensions, refer to --> [ Valve Dimensions ] [1][2]Specifications.
• Check valve guides, refer to --> [ Valve Guide, Checking ] Testing and Inspection.
23 Exhaust valve
• Do not rework, only lapping is permitted.
• Mark installed position for reinstallation
• Valve dimensions, refer to --> [ Valve Dimensions ] [1][2]Specifications.
• Check valve guides, refer to --> [ Valve Guide, Checking ] Testing and Inspection.
Installed Position of Valve Spring
• The tight spring coils - arrow - face toward cylinder head.