Camshaft: Service and Repair
WM 150520 Removing and installing camshafts (includes setting timing) - Turbo
Tools
Technical values
Preliminary work
1. Remove engine.
=> 100119 Removing and installing engine.
2. Remove rear silencer.
=> 263319 Removing and installing rear silencer - Turbo.
3. Remove the engine carrier.
=> 103019 Removing and installing engine carrier - Turbo.
Engine carrier with holder for rear silencer (turbo)
4. Remove turbocharger.
=> 213019 Removing and installing turbocharger.
5. Remove exhaust manifold. Unscrew nine screws (M8 x 27) on each and remove manifold and seal.
=> 261019 Removing and installing exhaust manifold - Turbo.
6. Remove heat shield for ignition coils.
=> 261219 Removing and installing heat shield - Turbo.
7. Remove bar ignition modules.
=> 282019 Removing and installing bar ignition module - Turbo
7.1. Pull off cable plugs on bar ignition modules, hall sender and solenoid hydraulic valve (VVS) and unscrew two M6 x 12 cheese head bolts for the ground cables for the bar ignition modules.
7.2. In each case, unscrew one internal Torx (T30) countersunk screw (M6 x 16) and pull ignition coils out of the spark-plug recess.
8. Remove spark plugs.
=> 287020 Removing and installing spark plugs - Turbo.
9. Remove high-pressure pump.
=> 246319 Removing and installing high-pressure pump - Turbo.
10. Remove vacuum pump.
=> 477619 Removing and installing vacuum pump.
11. Remove cover for positive crankcase ventilation.
11.1. Cover on cylinder bank 1-3 -1- : Unscrew three external Torx screws (M6 x 20) -4- and replace O-ring -3- and moulded seal -2-.
Cover on positive crankcase ventilation 1-3
11.2. Cover on cylinder bank 4-6 -1- : Unscrew two external Torx screws (M6 x 20) -3- and replace O-ring -2-.
Cover on positive crankcase ventilation 4-6
12. Remove cylinder head cover.
=> 158219 Removing and installing cylinder head cover - Turbo.
Removing camshafts
NOTICE
Dirt and contamination
- Risk of damage to units or components
-> Protect components from dirt and contamination.
-> Clean or replace dirty components.
Information
Specifications for wrench sizes (a/f specifications) for screw heads are described as follows:
- Torx screws: (E.) for external Torx, (T.) for internal Torx.
- Hexagon-head bolts (internal and external hexagon): Wrench size (a/f)
Overview (view of cylinder bank 4-6):
Component overview for camshafts/cylinder head
Information
- The camshafts can only be removed in the overlapping position at the top dead centre of pistons 1 or 4.
- Only at this position can you be sure that the valves are not touching against the pistons and cannot be damaged when the engine turns.
1. Turn the engine at the assembly support so that the cylinder bank to be worked on is at the top.
2. Use special tool turning device 9773 -1- to turn the crankshaft clockwise at the vibration damper as far as the TDC marking on cylinder 1/4.
TDC marking on cylinder 1/4 on vibration damper
2.1. Fix the vibration damper in place above the staking bore using a locating pin 9595/1 -2-.
2.2. Check the position of the data matrix code on both camshafts. These must be facing the observer at overlapping position.
3. Check cam position on cylinders 1 and 4.
3.1. Overlap of cylinder 1: The cams must be facing downwards at an angle to the cylinder head wall -Arrows-.
Cam position on cylinder 1 at overlap
3.2. Overlap of cylinder 4: The cams are facing each other and are at a slight angle with respect to the spark-plug recess -Arrows-.
Cam position on cylinder 4 at overlap
4. Remove central screws on camshaft timing gears.
Central screws on camshaft timing gears
5. Loosen internal Torx central screw (T55, M12 x 1.5 x 60) on the outlet sprocket. To do this, counter with special tool holding wrench 9775 -1-.
Outlet sprocket threaded joint
6. Loosen internal Torx central screw (T55, M12 x 1.5 x 110) on the camshaft controller. To do this, counter with a long open-ended wrench (a/f 32) -1-.
Camshaft controller threaded joint
7. Remove chain tensioner.
7.1. Cylinder bank 1-3: Chain tensioner sitting on underside of the crankcase.
7.2. Cylinder bank 4-6: Chain tensioner sitting on top of cylinder head.
7.3. Replace sealing ring.
8. Loosen four external Torx screws (E10, M6 x 55) on the bearing saddle -2-.
8.1. Then loosen the external Torx screws (M6 x 37) for the mounting saddles from the outside to the inside -1-.
Camshaft mount
9. Lift camshafts out of the cylinder head. Lay the timing chain into the chain housing in the cylinder head.
9.1. Unscrew central screw on the camshaft controller.
9.2. Lift up the camshaft controller -1- with the intake camshaft and pull the shaft -2- to the flywheel side using one hand. Pay particular attention to the friction plate when doing so. Lift up the timing chain and remove the camshaft controller.
Intake camshaft with camshaft controller
9.3. Join the controller to the intake camshaft again for storage. Tighten screw only slightly.
9.4. Remove outlet camshafts complete with the sprocket.
Outlet camshaft with sprocket
10. Replace the friction plates in the sprocket and on the intake camshaft.
Information
- The camshaft controller must not be cleaned in a parts washer.
- Only the outside can be cleaned using a clean, lint-free cloth.
11. Clean components.
11.1. Do not clean the camshaft controller in a parts washer.
Installing camshafts
Component identification
1. Intake camshafts:
Intake camshafts
2. Outlet camshafts:
Outlet camshafts
3. Distinguishing features of outlet sprockets:
Outlet sprockets
4. Camshaft mount:
- Bearing saddle: Matching number for upper and lower part for cylinder head, engraved on front (chain box side).
- Bearing cover: Matching number for cylinder head and allocation to intake and outlet side of cylinder (e.g. A1 for outlet cylinder 1), engraved.
Installing camshafts, setting timing - cylinder bank 4-6
NOTICE
Dirt and contamination
- Risk of damage to units or components
-> Protect components from dirt and contamination.
-> Clean or replace dirty components.
Information
Before final tightening (torque angle) of the central screws, the special tool staking tool 9772 must be removed.
Information
Specifications for wrench sizes (a/f specifications) for screw heads are described as follows:
- Torx screws: (E.) for external Torx, (T.) for internal Torx.
- Hexagon-head bolts (internal and external hexagon): Wrench size (a/f)
1. Turn the crankshaft clockwise (running direction of engine) to 60° before TDC at the vibration damper.
1.1. This position is marked U 3/6 on the surface.
Position U 3/6 (60° before TDC)
1.2. Fix in place using a long locating pin 9595/1 -1-.
2. Turn the engine at the assembly support so that the cylinder bank to be fitted is at the top.
3. Fit lower part of bearing saddle -1-.
3.1. Check position of oil bores and position and fit the component on the dowel sleeves.
Lower part of bearing saddle 4-6
4. Oil the bearing surfaces of the camshafts with new engine oil. When rebuilding the engine, apply a light coating of Optimol Optipit grease (Part No. 000.043.204.17) on the bearings.
4.1. Check that all hydraulic tappets are installed correctly.
5. Fit the outlet camshaft and sprocket.
Fitting outlet camshaft and sprocket (view of cylinder bank 1-3)
5.1. Check that the friction plate -1- is fitted in the sprocket.
Friction plate in sprocket
5.2. Tighten the central screw only slightly so that the sprocket can still turn.
5.3. Lift the timing chain and position the camshaft and sprocket at the overlapping position of cylinder 4. The cams must be facing downwards at an angle with respect to the spark-plug recess and the camshaft must lie loosely in the bearing positions.
6. Fit the intake camshaft.
6.1. Check that the friction plate -2- is fitted on the shaft -1- ( -Arrow- ).
Position of friction plate on intake camshaft
6.2. Lift the timing chain and engage and secure the camshaft controller -1-. Guide the intake camshaft -2- into the controller and set it to the overlapping position of cylinder 4. The cams must be facing downwards at an angle with respect to the spark-plug recess and the camshaft must lie loosely in the bearing positions.
Fitting intake camshaft (view of cylinder bank 1-3)
6.3. Screw in internal Torx central screw (T55, M12 x 1.5 x 110) loosely by hand so that the controller can still turn.
7. Check cam positions for cylinder 4. The cams must be facing downwards at an angle with respect to the spark-plug recess.
Fitting camshafts for cylinder 4 at overlapping position
7.1. Another feature is a data matrix code marking on the reconditioned surface next to the dihedron -Lupe-. These markings must be facing the observer at overlapping position.
Marking on camshafts 4-6 at overlap
CAUTION
Timing chains positioned incorrectly
- Too much wear on sprockets and timing chains
- Engine damage
-> Perform a visual inspection to check the position of the timing chains on the tensioning and guide rails.
8. Use a torch to check that the timing chains are on the tensioning and guide rails between the guide pins -Arrow-.
Guide pins on tensioning and guide rails
9. Oil the bearing surfaces of the camshafts with new engine oil. When rebuilding the engine, apply a light coating of Optimol Optipit grease (Part No. 000.043.204.17) on the bearings.
10. Fit bearing saddle and bearing covers.
10.1. Fit bearing saddle and bearing covers and observe markings.
10.2. Fit four external Torx screws (E10, M6 x 55) on the bearing saddle.
10.3. Fit two external Torx screws (E10, M6 x 37) on each of the bearing covers.
10.4. Fit and tighten screws according to the specified tightening sequence -1 bis 16-.
=> Initial tightening: 5 Nm (3.5 ftlb.)
=> Subsequent tightening: 5 Nm (3.5 ftlb.)
=> Torque angle: 50°
Tightening sequence for mounting camshafts 4-6
11. Check axial bearing clearance by pulling and pressing on the camshaft controller and sprocket.
11.1. There must be perceptible clearance because otherwise the shafts will have to be fitted again.
12. Screw in and tighten chain tensioner with a new seal.
=> Tightening torque: 80 Nm (59 ftlb.)
Set the timing, cylinder bank 4-6:
13. Check cam position for cylinder 4 -Arrows-.
Cam position for cylinder 4 at overlap
Data matrix code is facing the observer.
Marking on camshafts 4-6 at overlap
14. The adjusting device is positioned on the reconditioned dihedron of the camshafts -Arrows-.
Position of dihedron of camshafts 4-6
14.1. Check the position of the intake and outlet side -Arrows-.
Fitting position of staking tool for cylinder bank 4-6
15. Fit special tool staking tool 9772 -1- on the cylinder head and camshafts.
15.1. Secure on the cylinder head with four screws (M6 x 25) -2-. Tighten screws only slightly.
Staking tool screws for cylinder bank 4-6
16. Tighten adjusting screw -Arrow- on the staking tool to the specified torque by turning it clockwise.
Tightening adjusting screw on staking tool
=> Tightening torque: 10 Nm (7.5 ftlb.)
17. Turn the crankshaft clockwise (running direction of engine) to the TDC marking at the vibration damper.
17.1. This position is marked TCD 1/4 on the surface.
17.2. Fix in place using a long locating pin 9595/1 -1-.
TDC marking on cylinder 1/4 on vibration damper
18. Tighten central screws for sprocket and camshaft controller to the prescribed initial tightening torque.
Central screws on camshaft timing gears
18.1. Tighten central screw on sprocket -1- initially and counter with a holding wrench 9775 while doing this.
=> Initial tightening: 30 Nm (22 ftlb.)
18.2. Tighten central screw on camshaft controller -2- initially and counter with a long open-ended wrench (a/f 32) at the driver -3- while doing this.
=> Initial tightening: 35 Nm (26 ftlb.)
19. Staking tool 9772 must now be removed.
19.1. Loosen the adjusting screw. A creaking noise is completely normal due to the tension in the tool.
19.2. Unscrew fastening screws on the cylinder head and remove the tool.
20. Tighten central screws on the sprocket and camshaft controller to the prescribed final torque using a torque angle wrench.
20.1. Tighten central screw on sprocket and counter with a holding wrench 9775 -1- while doing this.
Outlet sprocket threaded joint
=> Torque angle: 65°+/-5°
20.2. Tighten central screw on camshaft controller and counter with a long open-ended wrench (a/f 32) -1- while doing this.
Camshaft controller threaded joint
=> Torque angle: 125°+/-5°
Installing camshafts, setting timing - cylinder bank 1-3
NOTICE
Dirt and contamination
- Risk of damage to units or components
-> Protect components from dirt and contamination.
-> Clean or replace dirty components.
CAUTION
Timing chains positioned incorrectly
- Too much wear on sprockets and timing chains
- Engine damage
-> Perform a visual inspection to check the position of the timing chains on the tensioning and guide rails.
Information
Before final tightening (torque angle) of the central screws, the special tool staking tool 9772 must be removed.
Information
Specifications for wrench sizes (a/f specifications) for screw heads are described as follows:
- Torx screws: (E.) for external Torx, (T.) for internal Torx.
- Hexagon-head bolts (internal and external hexagon): Wrench size (a/f)
1. Continue to turn the crankshaft clockwise (running direction of engine) to 60° before TDC at the vibration damper.
1.1. This position is marked U 3/6 on the surface.
Position U 3/6 (60° before TDC)
1.2. Fix using a long locating pin 9595/1 -1-.
2. Turn the engine on the assembly support until cylinder bank 1-3 is at the top.
3. Fit lower part of bearing saddle -1-.
3.1. Check position of oil bores and position and fit the component on the dowel sleeves.
Lower part of bearing saddle 1-3
4. Oil the bearing surfaces of the camshafts with new engine oil. When rebuilding the engine, apply a light coating of Optimol Optipit grease (Part No. 000.043.204.17) on the bearings.
4.1. Check that all bucket tappets are installed correctly.
5. Fit the outlet camshaft and sprocket.
Outlet camshaft and sprocket (view of cylinder bank 1-3)
5.1. Check that the friction plate is fitted in the sprocket.
Friction plate in sprocket
5.2. Screw in the central screw but make sure that the sprocket can still turn slightly.
5.3. Lift the timing chain and position the camshaft and sprocket at the overlapping position of cylinder 1. The cams must be facing downwards at an angle with respect to the cylinder head wall and the camshaft must lie loosely in the bearing positions.
5.4. Another feature is the data matrix code marking on the reconditioned surface next to the dihedron -Lupe-. These markings must be facing the observer at overlapping position.
Marking on camshafts 1-3 at overlap
6. Fit the intake camshaft.
6.1. Check that the friction plate is fitted on the shaft.
Position of friction plate on intake camshaft
6.2. Lift the timing chain and engage and secure the camshaft controller. Guide the intake camshaft into the controller and set it to the overlapping position of cylinder 4. The cams must be facing downwards at an angle with respect to the spark-plug recess and the camshaft must lie loosely in the bearing positions.
Intake camshaft with camshaft controller
6.3. The square marking on the camshaft must be facing the observer.
6.4. Screw in the internal Torx central screw (T55, M12 x 1.5 x 110) loosely by hand so that the controller can still turn.
7. Check cam position of cylinder 1 before fitting the bearing saddle and bearing covers. The cams must be facing the cylinder head wall and must point downwards at an angle.
7.1. Check the position of the outlet sprocket again (position of driver for high-pressure pump).
8. Use a torch to check that the timing chains are on the tensioning and guide rails between the guide pins -Arrow-.
Guide pins on tensioning and guide rails
9. Oil the bearing surfaces of the camshafts with new engine oil. When rebuilding the engine, apply a light coating of Optimol Optipit grease (Part No. 000.043.204.17) on the bearings.
10. Fit bearing saddle and bearing covers.
10.1. Fit bearing saddle and bearing covers and observe markings.
10.2. Fit four external Torx screws (E10, M6 x 55) on the bearing saddle.
10.3. Fit two external Torx screws (E10, M6 x 37) on each of the bearing covers.
10.4. Fit and tighten screws according to the specified tightening sequence.
=> Initial tightening torque for bearing covers and bearing saddle: 5 Nm (3.5 ftlb.)
=> Re-tightening bearing covers and bearing saddle: 5 Nm (3.5 ftlb.)
=> Final tightening torque angle for bearing covers and bearing saddle: 50 °
Tightening sequence for mounting camshafts 1-3
11. Check axial bearing clearance by pulling and pressing on the camshaft controller and sprocket.
11.1. There must be perceptible clearance because otherwise the shafts will have to be fitted again.
12. Screw in and tighten chain tensioner with a new seal.
=> Tightening torque for chain tensioner: 80 Nm (59 ftlb.)
Set the timing, cylinder bank 1-3: Essentially, the timing for cylinder bank 1-3 is set in the same way as for cylinder bank 4-6.
13. Check cam position for cylinder 1 and markings again.
Cam position for cylinder 1 at overlap
Marking on camshafts 1-3 at overlap
14. The adjusting device is positioned on the reconditioned dihedron of the camshafts -Arrows-.
Position of dihedron of camshafts 1-3
14.1. Check the position of the intake and outlet side.
Fitting position of staking tool for cylinder bank 1-3
15. Fit special tool staking tool 9772 on the cylinder head and camshafts.
15.1. Secure on the cylinder head with four screws (M6 x 25) and tighten screws hand-tight.
Staking tool screws for cylinder bank 1-3
16. Tighten adjusting screw on the staking tool by turning it clockwise.
=> Tightening torque for adjusting screw: 10 Nm (7.5 ftlb.)
Tightening adjusting screw on staking tool
17. Turn the crankshaft clockwise (running direction of engine) to the TDC marking at the vibration damper.
17.1. This position is marked TCD 1/4 on the vibration damper.
17.2. Fix using a long locating pin 9595/1.
TDC marking on cylinder 1/4 at vibration damper
18. Tighten central screws for sprocket and camshaft controller to the prescribed initial tightening torque.
Central screws on camshaft timing gears
18.1. Tighten central screw on sprocket -1- initially, countering with a holding wrench 9775.
=> Initial tightening torque for central screw on outlet sprocket: 30 Nm (22 ftlb.)
18.2. Tighten central screw on camshaft controller -2- initially, countering with a long open-ended wrench (a/f 32) at the driver -3-.
=> Initial tightening torque for central screw on camshaft controller: 35 Nm (26 ftlb.)
19. Remove special tool staking tool 9772.
19.1. Loosen the adjusting screw. A creaking noise is completely normal due to the tension in the tool.
19.2. Unscrew fastening screws on the cylinder head and remove the tool.
20. Tighten central screws on the sprocket and camshaft controller to the prescribed final torque using a torque angle wrench.
20.1. Tighten central screw on sprocket and counter with a holding wrench 9775 -1- while doing this.
=> Final tightening torque angle for central screw on outlet sprocket: 65 °
Outlet sprocket threaded joint
20.2. Tighten central screw on camshaft controller, countering with a long open-ended wrench (a/f 32) -1-.
=> Final tightening torque angle for central screw on camshaft controller: 125 °
Camshaft controller threaded joint
21. Then check the position of the camshafts on both sides again (pay attention to overlapping position).
21.1. It must be possible to screw in the adjusting screw by hand at the staking tool 9772.
21.2. Remove the tool and complete the engine.
Subsequent work
1. Install cylinder head cover.
=> 158219 Removing and installing cylinder head cover - Turbo.
2. Fit cover for positive crankcase ventilation.
2.1. Fit cover for cylinder bank 1-3 -1- with new O-rings and moulded seal and secure with three external Torx screws (E10, M6 x 25) -4-.
Cover on positive crankcase ventilation 1-3
2.2. Fit cover for cylinder bank 4-6 -1- with a new O-ring and secure with two external Torx screws (E10, M6 x 25) -3-.
Cover on positive crankcase ventilation 4-6
=> Tightening torque: 13 Nm (9.5 ftlb.)
3. Install high-pressure pump.
=> 246319 Removing and installing high-pressure pump - Turbo.
=> Tightening torque: 13 Nm (9.5 ftlb.)
4. Install vacuum pump.
=> 477619 Removing and installing vacuum pump.
=> Tightening torque: 13 Nm (9.5 ftlb.)
5. Fit spark plugs.
=> 287020 Removing and installing spark plugs - Turbo.
6. Fit bar ignition modules.
=> 282019 Removing and installing bar ignition module - Turbo.
6.1. Fit and tighten one internal Torx (T30) countersunk screw (M6 x 16) on each.
=> Tightening torque: 10 Nm (7.5 ftlb.)
6.2. Plug in cable plugs for bar ignition modules, hall sender and solenoid hydraulic valve (VVS) and screw on two ground cables for each.
=> Tightening torque: 10 Nm (7.5 ftlb.)
7. Fit heat shield.
=> 261219 Removing and installing heat shield - Turbo.
7.1. Fit and tighten four external Torx screws (M6 x 12).
=> Tightening torque: 10 Nm (7.5 ftlb.)
8. Fit exhaust manifolds with a new seal.
8.1. Fit and tighten nine external Torx screws (M8 x 27) on each. Observe tightening sequence.
=> 261019 Removing and installing exhaust manifold - Turbo.
=> Tightening torque: 30 Nm (22 ftlb.)
9. Fit the turbocharger.
=> 213019 Removing and installing turbocharger.
10. Install engine carrier.
=> 103019 Removing and installing engine carrier - Turbo.
11. Install rear silencer.
=> 263319 Removing and installing rear silencer - Turbo.
12. Install the engine.
=> 100119 Removing and installing engine.