Camshaft, Lifters and Push Rods: Service and Repair
Valvetrain, Assembly Overview
1 Exhaust valve
• Do not rework, only grinding is permitted
• Valve dimensions => [ Valve Dimensions ]
• Check valve guides => [ Valve Guides, Checking ] Testing and Inspection
2 Cylinder Head
3 Valve guide
• checking => [ Valve Guides, Checking ] Testing and Inspection
4 Valve stem seal
5 Valve spring
6 Valve spring plate
7 Valve keepers
8 Hydraulic valve play balancing element
• Do not interchange
• Lubricate contact surface
9 Exhaust camshaft
• Check radial clearance using Plastigage (roller rocker lever removed)
• Radial play on bearing -dia. 24 mm: 0.024 to 0.066 mm
• Radial play on bearing -dia. 32 mm: 0.030 to 0.051 mm
• Run-out: max. 0.04 mm
10 Cylinder head cover
• With integrated camshaft bearings
• Clean sealing surface, reworking is not permitted.
• Remove old sealant residue.
11 Bolt
• Replace
• Tightening order => [ Cylinder head cover tightening sequence ]
12 O-ring
• Replace
• Coat with engine oil
13 Sealing plugs
14 Intake camshaft
• Check radial clearance using Plastigage (roller rocker lever removed)
• Radial play on bearing -dia. 24 mm: 0.024 to 0.066 mm
• Run-out: max. 0.04 mm
15 Sealing cap
• Replace
• Removing: With the cylinder head cover installed, pierce through one side of the cover with an awl and pry it out
• Installing: Without sealant, press in 1 to 2 mm using the thrust piece (3334)
16 Intake valve
• Do not rework, only grinding is permitted
• Valve dimensions => [ Valve Dimensions ]
• Check valve guides => [ Valve Guides, Checking ] Testing and Inspection
Cylinder head cover tightening sequence
- Replace bolts
- Hand-tighten bolts in several stages 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 -.
• Ensure guide frame is not tilted.
Valve Dimensions
• Intake and exhaust valves must not be refaced by grinding. Only grinding is permitted.
