Valvetrain Overview
Valvetrain Overview
1 Intake Camshaft
• Check radial clearance with Plastigage, wear limit: 0.1 mm
• Runout: maximum 0.01 mm
• Checking axial play, refer to => [ Camshaft Axial Play, Checking ] Testing and Inspection.
• Identification, refer to => [ Camshaft Identification ] Application and ID.
• Removing and installing, refer to => [ Camshafts ] Service and Repair.
2 Camshaft Bearing Cap
• Installed position, refer to => [ Camshaft Bearing Caps
Installed Position ] Service and Repair.
• Installation sequence, refer to => [ Camshafts ] Service and Repair.
3 Exhaust Camshaft
• Check radial clearance with Plastigage, wear limit: 0.1 mm
• Runout: maximum 0.01 mm
• Checking axial play, refer to => [ Camshaft Axial Play, Checking ] Testing and Inspection.
• Identification, refer to => [ Camshaft Identification ] Application and ID.
• Removing and installing, refer to => [ Camshafts ] Service and Repair.
4 Nut
• 5 Nm + 45° (1/8) additional turn.
5 Seal
• If one seal is leaking, replace all of them.
• Lubricate the contact surfaces of the seal when installing the control housing.
• Do not spread the seals excessively when installing.
6 Control Housing
• Lubricate the contact surface of the seals before installing.
• Camshaft adjustment valves, removing and installing. Refer to => [ Camshaft Adjuster Valves ] Camshaft Adjuster Valves.
• Marks for valve timing, refer to => [ Marks on Control Housing ] Adjustments.
• Overview, refer to => [ Control Housing Overview ] Description and Operation.
• Check control housing strainer for contamination before installation. Refer to => [ Checking Control Housing Strainer for Contaminants ] Description and Operation.
• Removing and installing, refer to => [ Camshafts ] Service and Repair.
7 Bolt
• 8 Nm
• Install using locking fluid (D 000 600 A2).
8 Exhaust Camshaft Adjuster
• Identification: 32A
• Rotate the engine only with the camshaft adjuster and chain installed.
• Camshaft adjustor with timing chain, installing. Refer to => [ Camshaft Adjuster with Timing Chain, Installing ] Camshaft Adjuster with Timing Chain, Installing.
9 Intake Camshaft Adjuster
• Identification: 24E
• Rotate the engine only with the camshaft adjuster and chain installed.
• Camshaft adjustor with timing chain, installing. Refer to => [ Camshaft Adjuster with Timing Chain, Installing ] Camshaft Adjuster with Timing Chain, Installing.
10 Bolt
• 60 Nm + 90° (1/4) additional turn
• Replace
• Contact surface of the adjuster wheel and bolt head must be dry when installing.
• When removing and installing, counter hold the camshaft using a 27 mm open end wrench. Refer to => [ Camshafts ] Service and Repair.
11 Cylinder Head Height
• Minimum height: a = 139.9 mm
12 Drive Pinion for the High Pressure Pump
• Vehicles without a vacuum pump.
With needle bearing lying inside.
Lubricate the needle bearing before installing.
13 Bearing Shaft (without Input Shaft)
• Vehicles without a vacuum pump
Ring groove in the bearing shaft faces forward
• Vehicles with a vacuum pump
The input shaft only fits into the drive pinion in one position.
14 Valves
• Do not regrind, only lapping is permitted.
• Valve dimensions, refer to => [ Valve Dimensions ] [1][2]Specifications.
15 Alignment Bushing
16 Cylinder Head
• Check for distortion, refer to => [ Checking Cylinder Head
for Distortion ] Cylinder Head Overview.
• Removing and installing, refer to => [ Cylinder Head ] Service and Repair.
• Refacing valve seats, refer to => [ Valve Seat, Refacing ] Service and Repair.
• After replacing, replace the entire amount of coolant.
17 Pump Plunger
• Note the installed position.
18 Support Element
• Before installing, check the camshaft axial play. Refer to => [ Camshaft Axial Play, Checking ] Testing and Inspection.
• Do not interchange
• With hydraulic valve clearance compensation.
19 Valve Stem Seal
• Replacing, refer to => [ Valve Stem Seals ] Service and Repair.
20 Timing Chain
• Mark the direction of rotation before removing (installed position). Refer to => [ Identifying the Timing Chain ] Description and Operation.
• Camshaft adjustor with timing chain, installing. Refer to => [ Camshaft Adjuster with Timing Chain, Installing ] Camshaft Adjuster with Timing Chain, Installing.
21 Securing Clip
• Check clip for secure seating.
22 Roller Rocker Lever
• Before installing, check camshaft axial play. Refer to => [ Camshaft Axial Play, Checking ] Testing and Inspection.
• Do not interchange.
• Check the roller for ease of movement.
• Lubricate the contact surface.
• Use the securing clip to clip onto the support element when installing.
23 Valve Spring
• Note the installed position.
• Removing and installing, refer to => [ Valve Stem Seals ] Service and Repair.
24 Valve Spring Plate
25 Valve Retainers