11 31... Service solution - replacing intake camshaft (N20)
Special tools required:
Necessary preliminary tasks:
- Remove DME CONTROL UNIT .
- Remove CYLINDER HEAD COVER
- Check TIMING
- Remove INTAKE ADJUSTER
Removal:
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.
Position special tool 11 7 110 on return spring (1) (see arrows).
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.
Left and right return springs (1) must be positioned in lateral guide of special tool 11 7 110 .
Preload return spring with lever (1) on special tool 11 7 110 in direction of arrow.
Lock special tool 11 7 110 with catch on lever (1).
Release screw (1).
Lever (1) is preloaded.
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.
Release special tool 11 7 110 in direction of arrow from return spring (1).
Return springs (1) remain on the engine.
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 .
Remove intake camshaft.
Installation:
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.
Insert intake camshaft so that data code (1) on mounting flats points upwards.
Position intake camshaft so that cams point downward at an angle and to the left.
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 .
Position special tool 11 7 110 on return spring.
Clamp throttle return spring with knurled screw (1) in direction of arrow.
Return spring (1) is positioned correctly when latching hooks surround return spring (1).
Check return spring on intermediate lever to ensure correct installation position.
Press special tool 11 7 110 to stop in direction of arrow.
Install return spring (2) on gate.
Check that rocker arm (3) is in correct installation position.
Tighten bolt (1).
Tightening torque 11 37 2AZ .
Lever (1) is preloaded.
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 .
Required follow-up work:
Install INTAKE ADJUSTER .
Adjust VALVE TIMING .
Fit CYLINDER HEAD COVER .
Install DME CONTROL UNIT .