11 31 ... Service solution - replacing intake camshaft (N20, N26)

WARNING: This page is about a different variant/trim than selected.

Special tools required:

WARNING: Risk of injury in event of incorrect use.

IMPORTANT: Improper handling. Risk of damage!

Necessary preliminary tasks:

Removal:

NOTE: Injector shafts shown removed for purposes of clarity.

IMPORTANT: Secure eccentric shaft (1) with open-end spanner (3) (risk of return stroke).

Fig 1: Adjusting Eccentric Shaft Using Hexagon Socket Wrench And Open-End Spanner

Slowly adjust eccentric shaft (1) to minimum lift via servomotor using 4-mm hexagon socket wrench (2) and open-end spanner (3).

Release bolt (1) on the oil spray nozzle.

Tightening torque 11 37 4AZ .

Unclip oil spray nozzle (2) from the bracket on the actuator drive (3) in direction of arrow.

Fig 2: Removing Oil Spray Nozzle From Bracket On Actuator Drive

Position special tool 11 7 110 on return spring (1) (see arrows).

Fig 3: Locating Return Spring

WARNING: Risk of injury in event of incorrect use.

IMPORTANT: Improper handling. Risk of damage!

Fig 4: Turning Knurled Screw

Place special tool 11 7 110 flat on cylinder head.

Turn knurled screw (1) in direction of arrow until both clamping levers secure return spring in gate.

Return spring is correctly preloaded when both clamping levers are parallel to guide block.

Fig 5: Installing Return Spring Using Special Tool (11 7 110)

IMPORTANT: Risk of damage!

Left and right return springs (1) must be positioned in lateral guide of special tool 11 7 110 .

Fig 6: Locating Return Springs Position In Lateral Special Tool (11 7 110)

Preload return spring with lever (1) on special tool 11 7 110 in direction of arrow.

Fig 7: Checking Preload Return Spring With Lever On Special Tool (11 7 110)

Lock special tool 11 7 110 with catch on lever (1).

IMPORTANT: Screw connection on throttle return spring can only be released with secured special tool 11 7 110 .

Fig 8: Locating Clamp Return Spring With Knurled Screw

Release screw (1).

Fig 9: Identifying Screw And Special Tool (11 7 110)

WARNING: Risk of injury in event of incorrect use.
Lever (1) is preloaded.

IMPORTANT: Improper handling. Risk of damage!

Fig 10: Pressing Back Latching Hook Using Special Tool (11 7 110)

Secure lever (1).

Press back latching hook (2).

Return spring tension can now be released.

Release knurled screw (1) on special tool 11 7 110 in direction of arrow.

Fig 11: Releasing Knurled Screw On Special Tool (11 7 110)

Release special tool 11 7 110 in direction of arrow from return spring (1).

Fig 12: Releasing Special Tool (11 7 110) From Return Spring

Return springs (1) remain on the engine.

Fig 13: Identifying Return Springs

NOTE: All bearing caps are identified with numbers from 1 to 4.

The front bearing cap is a thrust bearing and does not have an identification.

Release screws on all bearing caps (1 to 10).

Set down all bearing caps in a tidy and orderly fashion on special tool 11 4 481 .

Fig 14: Right Intake Camshaft Bearing Cap Bolts Tightening/Loosening Sequence (N20)

IMPORTANT: Do not remove intermediate levers (2). Mixing up the intermediate levers (2) will cause the engine to suffer idle-speed fluctuations.

Fig 15: Identifying Intake Camshaft

Remove intake camshaft.

Installation:

IMPORTANT: Marks of intake and exhaust camshafts are different.

Mixing up the intake and exhaust camshaft will result in engine damage.

A Exhaust camshaft.

E Intake camshaft

Fig 16: Identifying Intake And Exhaust Camshafts Marks

Insert intake camshaft so that data code (1) on mounting flats points upwards.

Fig 17: Identifying Camshaft Data Code

Position intake camshaft so that cams point downward at an angle and to the left.

Fig 18: Locating Cams Point

NOTE: All bearing caps are identified with numbers from 1 to 4.

The front bearing cap is a thrust bearing and does not have an identification.

Insert screws on all bearing caps from (10) to (1).

Tightening torque 11 31 3AZ .

Fig 19: Right Intake Camshaft Bearing Cap Bolts Tightening/Loosening Sequence (N20)

Position special tool 11 7 110 on return spring.

Fig 20: Positioning Special Tool (11 7 110) On Return Spring

Clamp throttle return spring with knurled screw (1) in direction of arrow.

Fig 21: Clamping Throttle Return Spring With Knurled Screw

Return spring (1) is positioned correctly when latching hooks surround return spring (1).

Fig 22: Positioning Return Spring

WARNING: Risk of injury in event of incorrect use.

IMPORTANT: Improper handling. Risk of damage!
Check return spring on intermediate lever to ensure correct installation position.

Fig 23: Pressing Special Tool (11 7 110)

Press special tool 11 7 110 to stop in direction of arrow.

Install return spring (2) on gate.

IMPORTANT: Insert return spring (2) in intermediate lever (1) (see arrow).
Check that rocker arm (3) is in correct installation position.

Fig 24: Inserting Return Spring In Intermediate Lever

IMPORTANT: Check that intermediate lever (1) is installed in correct position on eccentric shaft (2).

Fig 25: Identifying Eccentric Shaft Position

IMPORTANT: Observe thread on cylinder head. Risk of damage!

Tighten bolt (1).

Tightening torque 11 37 2AZ .

Fig 26: Identifying Bolt And Special Tool (11 7 110)

WARNING: Risk of injury in event of incorrect use.
Lever (1) is preloaded.

IMPORTANT: Improper handling. Risk of damage!

Fig 27: Pressing Back Latching Hook Using Special Tool (11 7 110)

Secure lever (1).

Press back latching hook (2).

Return spring tension can now be released.

Check installation position of intermediate lever and return spring again , remove special tool 11 7 110 .

Retract oil spray nozzle (2) on actuator drive (3).

Engage bolt (1) and release back to 90°.

For exact positioning of the oil spray nozzle (2) audibly clip it in at the top.

Tightening torque 11 37 4AZ .

Fig 28: Positioning Oil Spray Nozzle At Top

Required follow-up work:

Install INTAKE ADJUSTER .

Adjust VALVE TIMING .

Fit CYLINDER HEAD COVER .

Install DME CONTROL UNIT .