Camshaft, Lifters and Push Rods: Service and Repair
Valvetrain Overview
• Cylinder heads with cracks between the valve seats, or the valve seat and the spark plug threads, can continue to be used without reducing the service life, as long as the cracks have a Max. width if 0.3 mm, or only the first 4 threads of the spark plug threads are cracked.
• The cylinder head and guide frame must be replaced together.
• Do not start the engine for approximately 30 minutes after installing the camshafts. The hydraulic lash adjusters must seat themselves (otherwise the valves will crash into the pistons).
• After working on the valvetrain and hydraulic lash adjusters, 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 the gaskets and seals.
1 Bolt
• 50 Nm + an additional 180° (1/2) turn.
• Always replace.
• Use the retainer (3036) to loosen and tighten.
2 Camshaft Sprocket
• Use the retainer (3036) to loosen and tighten.
3 Seal
• Removing and installing, refer to => [ Exhaust Camshaft Seal ] Service and Repair.
4 Cylinder Head
5 Valve Guide
• Checking, refer to => [ Valve Guide, Checking ] Testing and Inspection.
6 Valve Stem Seal
• Removing and installing, refer to => [ Valve Stem Seals ] Service and Repair.
7 Valve Spring
8 Spring Seat
9 Valve Retainer
10 Hydraulic Lash Adjuster
• Do not interchange.
• Lubricate the contact surfaces.
11 Woodruff Key
• Make sure it is secure.
12 Exhaust Camshaft
• Check the radial clearance using Plastigage(R) (the roller rocker arms are removed);
Wear limit: 0.1 mm
Run out: maximum 0.035 mm
13 Guide Frame
• With integrated camshaft bearings.
• Clean the sealing surface, reworking is not permitted.
• Remove any old sealant residue.
14 Bolt
• 8 Nm + an additional 90° (1/2) turn.
• Always replace.
15 Camshaft Adjuster
• Removing and installing, refer to => [ Camshaft Adjuster ] Camshaft Adjuster.
16 Bolt
• 20 Nm + an additional 45° (1/8) turn.
• Use the retainer (3036) to loosen and tighten.
17 Intake Camshaft
• Check the radial clearance using Plastigage(R):
Wear limit: 0.1 mm
Run out: maximum 0.035 mm
18 Chain Tensioner
• Secure using the locking pin (T10115) before removing.
19 Timing Chain
• Removing and installing, refer to => [ Camshaft Adjuster ] Camshaft Adjuster.
• Check for wear.
20 Bolt
• 10 Nm
21 Bolt
• 10 Nm
22 Camshaft Position Sensor (G40)
23 Exhaust Valve
• Do not grind, only hand lapping is permitted.
• Valve dimensions, refer to => [ Valve Dimensions ] [1][2]Specifications.
• Valve guide, checking. Refer to => [ Valve Guide, Checking ] Testing and Inspection.
24 Intake Valve
• Do not grind, only hand lapping is permitted.
• Valve dimensions, refer to => [ Valve Dimensions ] [1][2]Specifications.
• Valve guide, checking. Refer to => [ Valve Guide, Checking ] Testing and Inspection.
25 Sealing Cap
• Always replace.
• Removing: Insert a screwdriver into the center of the cap and pry out.
• Installing: Do not use sealant, press in 1 to 2 mm using the thrust piece (3334).