Camshaft, Lifters and Push Rods: Service and Repair
Valvetrain Overview
• Only remove the plastic protectors installed to protect the open valves immediately before positioning the cylinder head.
• When replacing the cylinder head or cylinder head gasket, the coolant must be completely replaced.
• Cylinder heads with cracks between the valve seats can continue to be used without reducing service life, as long as the cracks have a Max. width of 0.5 mm.
• After installing the camshafts, the engine may not be started for approximately 30 minutes. The hydraulic equalization elements must seat themselves (otherwise the valves will crash into the pistons).
• After working on the valvetrain and lifters, carefully rotate the crankshaft by hand at least 2 full revolutions before starting to be sure that valves do not strike the pistons.
• Always replace gaskets and seals.
1 Seal
• Do not additionally oil or grease the sealing lip of the seal.
• Before installing, remove any remaining oil from the camshaft journal with a clean cloth.
• To install, tape over the groove on the camshaft taper.
• Removing and installing, refer to => [ Camshaft Seal ] Service and Repair.
2 Bolt
• 10 Nm
3 Nut
• 10 Nm
4 Bearing Frame
• Follow the sequence for loosening and tightening => [ Camshafts ] Service and Repair.
• Seal using silicone adhesive sealant (D 176 501 A1).
5 Exhaust Camshaft
• Removing and installing, refer to => [ Camshafts ] Service and Repair.
6 Intake Camshaft
• Removing and installing, refer to => [ Camshafts ] Service and Repair.
7 Roller Rocker Lever
• Mark the installed position.
• Do not interchange.
• Check the roller for ease of movement.
• Lubricate the running surfaces before installing.
8 Hydraulic Adjusting Elements
• Mark the installed position.
• Do not interchange.
• Lubricate the running surfaces before installing.
9 Valve
• Mark the installed position.
• Do not rework, only lapping is permitted.
• Valve dimensions, refer to => [ Valve Dimensions ].
• Checking valve guides, refer to => [ Valve Guide, Checking ] Testing and Inspection.
10 Cylinder Head
• See the note.
• Checking for distortion, refer to => [ Checking the Cylinder Head for Distortion ] Cylinder Head Overview.
• Removing and installing, refer to => [ Cylinder Head ] Cylinder Head.
• All of the coolant must be replaced after installation.
11 Valve Stem Seal
Replacing, refer to => [ Valve Stem Seals, Cylinder Head Installed ] Service and Repair.
12 Valve Spring
13 Valve Spring Plate
14 Valve Retainers
15 Cap
• Always replace
• Drive in using a suitable drift until it is flush.
Valve Dimensions
• Intake and exhaust valves must not be refaced by grinding. Only lapping is permitted.