2005 BMW 745i N62B44 Engine Workshop Manual
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N62 Engine
VANOS Sectional Views
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The figures above show a sectional view of one VANOS unit. The VANOS unit is secured
by a central bolt through the hub (7) to the camshaft. The timing chain connects the crank-
shaft with the housing of the unit.
There is a recess in the hub in which the locking pin (6) engages without oil pressure
(sprung). When the solenoid valve is activated to supply oil pressure to the VANOS unit,
the locking pin is compressed and releases the VANOS for adjustment.
The internal blades (9) are spring loaded (10) to provide a seal between the oil pressure
chambers (11 and 12). The torsion spring (3) acts against the camshaft torque.
42-02-4942-02-45
VANO’S Components
1. Housing with Sprocket 7. Hub
2. Front Plate 8. Black Plate
3. Torsion Plate 9. Blade
4. Lock Spring 10. Spring
5. Retaining Plate for Lock Spring 11. Pressure Chamber A
6. Spring Loaded Locking Pin 12. Pressure Chamber B
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N62 Engine
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When oil pressure is applied to chamber A, the blades are forced away from the VANOS
housing (counterclockwise). The blades are keyed into the hub which results in the hub
position being rotated in relation to the housing (with sprocket). The hub is secured to the
camshaft which changes the camshaft to sprocket relationship (timing).
The example below shows the a ad
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procedure together with the pressure progres-
sion based on the VANOS unit for the exhaust camshafts.
During this adjustment chamber B is open (through the solenoid) to allow the oil to drain
back through the cylinder head (internal reservoir).
Hydraulic Actuation - Chamber A
1. Front View of Vanos Unit 5. Engine Oil Pump
2. Side View of Vanos Unit 6. Supplied Oil from Pump (Switched Through Solenoid)
3. Camshaft Oil Port (Chamber B) 7. Supplied Oil Pressure (From Engine Oil Pump)
4. Solenoid Valve43-02-45
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N62 Engine
When the solenoid valve switches over, oil pressure is applied to chamber B. This forces
the blades (and hub) in a clockwise direction back to the initial position, again changing the
camshaft timing.
The example below shows the r re
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procedure together with the pressure progression
based on the VANOS unit for the exhaust camshafts.
During this adjustment chamber A is open (through the solenoid) to allow the oil to drain
back through the cylinder head (internal reservoir).
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42-02-44 Hydraulic Actuation - Chamber B
1. Front View of VANOS Unit 5. Engine Oil Pump
2. Side View of VANOS Unit 6. Oil Return (Switched through Solenoid)
3. Camshaft Oil Port (Chamber B) 7. Supplied Oil Pressure (From Engine Oil Pump)
4. Solenoid Valve
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N62 Engine
The chart below shows the VANOS unit camshaft adjustment possibilities. The valve lift
adjustment has also been incorporated.
The special feature of Valvetronic is that the air mass drawn in the cylinders can be easily
determined by the valve lift and closing time. The air mass can then be limited, thus the
term “load control”.
With the help of VANOS, the valve closing point can be easily selected within a defined
range. With valve lift control, the opening duration and cross section of the valve opening
can also be easily selected within a defined range.
Vacuum pump
The N62 engine requires a vacuum pump for the vacuum
assisted brake booster. With the throttle valve open while the
car is being driven, additional vacuum is needed.
The N62 vacuum pump has a second vacuum connection
(small hose) for the exhaust flap adjustment. The vacuum
pump is driven by cylinders 1-4 exhaust camshaft via the
VANOS unit. The pump is lubricated through an oil gallery
from the cylinder head.
42-02-03
Chart Exhaust & Intake Valve
1. Exhaust Valve Open
2. Exhaust Valve Closed
3. Intake Valve Open
4. Intake Valve Closed
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N62 Engine
Chain Drive
The camshafts are driven by a toothed chain, one for each cylinder bank. The oil pump is
driven by a separate roller chain.
1. Sensor wheels for the camshaft position sensor, cylinder bank 1-4
2. Tensioner Rail, Cylinder 5-8
3. Chain Tensioner, Cylinder Bank 5-8
4. Sensor Wheel for the camshaft position sensor, cylinder bank 5-8
5. Upper timing chain guide with integrated oil jet
6. Guide rail
7. Sprocket for Oil Pump Drive
8. Timing case lower section
9. Tensioning rail, cylinder bank 1-4
10. Solenoid Valve, VANOS exhaust camshaft
11. Solenoid Valve, VANOS intake camshaft
12. Upper Timing Chain Cover
13. Chain Tensioner, Cylinder Bank 1-4
14. VANOS exhaust camshaft Bank 1-4
15. Upper Timing Chain guide with integrated oil jet
16. VANOS intake camshaft 1-4Chain Drive
43-02-50
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N62 Engine
Toothed Chain
The camshafts are driven by the crankshaft
using newly developed maintenance free
toothed chains.
The toothed chain gear wheels are located on
the crankshaft and on the VANOS unit. Use of
the new toothed chains (1) optimizes the drive
chain rolling process and reduces noise.
Crankshaft Sprocket
The crankshaft sprocket (3) has three sets of gear
teeth:
1. One roller chain gear wheel for the oil pump drive.
2. Two toothed chain gear wheels for the camshaft drives.
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The sprocket will also be fitted to a 12-cylinder
engine variant which will be available in the future.
Please observe the installation instructions and the rel-
evant labels (V8 Front/V12 Front) when installing the
sprocket.
Chain Tensioner (cylinder bank 1-4)
A chain tensioner is mounted in the side of the cylinder
head for each camshaft drive chain. There is a guide
ball in the chain tensioner tip that moves in an arched
groove in the tensioning rail.
The tensioner seal must be replaced each time the
tensioner is disassembled. The tensioners are the
same for both the left and the right cylinder heads.
42-02-51
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Chain Tensioner
1. Chain Tensioner
2. Tensioning Rail
3. Bearing Pin
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N62 Engine
Tensioning Rail Bearing Pin
The bearing pin for the cylinder bank 1-4 drive
chain tensioning rail is hollowed. There is a ball
(check) valve in the bearing pin. The valve
opens at an oil pressure of 1 bar and allows
engine oil to flow to the tensioning rail via a port
(1).
Chain Tensioner (cylinder bank 5-8)
An oil jet has been fitted to lubricate the cylinder bank
5-8 drive chain. There is a valve in the oil jet which
opens at a pressure of 1 bar and supplies the drive
chain with engine oil.
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Refer to the Repair Instructions when using the
Special Tools shown below to adjust the camshaft tim-
ing.
42-02-53
42-02-54 Tensioning Rail Bearing Pin
1. Engine Oil Port to Tensioning Rail
2. Ball (check) Valve
3. Bearing Pin
4. Sealing Rings for Sealing the Tensioning Rail
Chain Tensioner
1. Chain Tensioner
2. Tensioning Rail
3. Oil Jet
42-02-7842-02-79
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N62 Engine
Cooling System
Coolant Circuit - 14 Liter Coolant Capacity
42-02-56
Cooling System (Circuit Flow)
1. Cylinder Head Bank 5-8 12. Radiator
2. Coolant Supply (heater core) 13. Radiator Partition (low temp section)
3. Water valve with electric water pump 14. Temperature Sensor
4. Cylinder Head Gasket 15. Water Pump
5. Coolant Supply Line 16. Radiator Return Flow
6. Cylinder Head Ventilation Lines 17. Radiator Ventilation Line
7. Hole (crankcase venting system) 18. Expansion Tank
8. Transmission oil lines 19. Thermostat
9. Oil/water heater exchanger for automatic transmission 20. Cylinder Head Bank 1-4
10. Thermostat for transmission oil heat exchanger 21. Vehicle Heater
11. Alternator Housing 22. Radiator (High Temperature Area)