2004 BMW 545i timing

Downloaded from www.Manualslib.com manuals search engine 2
N62 Engine
N62 Engine
Purpose of The System
The N62B44 engine is a completely new development from the NG (New Generation) series
and is available as a B44 (4.4 liter).
The development objectives were:
• Reduction in fuel consumption
• Reduction in emissions
• Increased power
• Improved torque and torque curve
• Improved engine acoustics
The most important features of
the new N62 engine are:
• 8 cylinders in a 90º V configu-
ration
• 2 four-valve cylinder heads
• Light-alloy design
• Newly-developed variable
intake manifold
• Valvetronic system
In conjunction with the Variable Intake Manifold, the Valvetronic system adapts the intake
valve lift to ensure optimum cylinder filling. The throttle valve use is limited during engine
operation to maintain a constant intake manifold vacuum.
T Th
he
e
N
N6
62
2
i
is
s
t
th
he
e
b
be
es
st
t
e
en
ng
gi
in
ne
e
i
in
n
i
it
ts
s
c
cl
la
as
ss
s.
.
A
At
t
t
th
hi
is
s
t
ti
im
me
e
t
th
he
er
re
e
i
is
s
n
no
o
o
ot
th
he
er
r
e
en
ng
gi
in
ne
e
o
on
n
t
th
he
e
m
ma
ar
rk
ke
et
t
w wh
hi
ic
ch
h
u
us
se
es
s
c
co
om
mp
pa
ar
ra
ab
bl
le
e
t
te
ec
ch
hn
no
ol
lo
og
gy
y.
.
To achieve these objectives, enhancements
were made in the following areas:
• Engine mechanicals
• Treatment of exhaust emissions
• Valve timing
• Engine management control
• Intake air flow
43-02-01

Downloaded from www.Manualslib.com manuals search engine Intake Manifold
The N62 engine is equipped with a Variable Intake Manifold making it possible to reach a
generous torque curve even at low engine speeds, without incurring losses in engine out-
put at higher speeds. It ensures that the engine exhibits optimum volumetric efficiency
through the entire range of speeds.
The new feature is the Variable Intake Manifold intake pipe length can be adjusted depend-
ing on the engine speed to provide efficient cylinder filling and scavenging. This is deter-
mined by the optimal matching of the intake pipe dimensions, the exhaust system and the
valve timing.
The intake manifold is located in the engine “V” and is mounted on the cylinder head intake
ports.
Function
In order to understand how engine speed relates to volumetric efficiency, the physical
processes within the intake pipe must be taken into consideration.
To ensure that there is good airflow to the engine cylinders, the intake pressure in front of
the intake valve should ideally be high. This means that good airflow (high gas molecule
density) in front of the intake valve is necessary.
8
N62 Engine
42-02-47

Downloaded from www.Manualslib.com manuals search engine Cylinder Heads
The two N62 cylinder heads are a new development from BMW. They are fitted with the
Valvetronic system. The secondary air ducts for subsequent exhaust gas treatment are
integrated in the cylinder heads. The cylinder heads are cooled by the “cross-flow” princi-
ple.
The inlet camshaft and the Valvetronic eccentric shaft are jointly guided by a bridge sup-
port. The cylinder heads are made from aluminum and are manufactured using gravity die-
casting. The upper timing chain housing is now an integral part of the cylinder head.
20
N62 Engine
Cylinder Head
1. Cylinder Head for Cylinder Bank 1-4 7. Mounting VANOS Intake Solenoid
2. Cylinder Head for Cylinder Bank 5-8 8. Mounting VANOS Outlet Solenoid
3. Upper Timing Chain Guide with Oil Jet 9. Oil Pressure Switch
4. Mounting for VANOS Intake Solenoid 10. Chain Tensioner Mount
5. Mounting for VANOS Outlet Solenoid 11. Upper Timing Chain Guide with Oil Jet
6. Chain Tensioner Mount43-02-20

Downloaded from www.Manualslib.com manuals search engine Cylinder Head Gaskets
The cylinder head gasket is a multi-layer steel
gasket with a rubber coating. This type of gas-
ket has previously been used on other engines.
The B44 head gasket has a 6 mm hole in a flap
on the outlet side of the cylinder head gasket.
The cylinder head bolts for the N62 engine are
M10x160 necked-down “stretch” bolts.
N No
ot
te
e:
:
T
Th
he
es
se
e
b
bo
ol
lt
ts
s
s
sh
ho
ou
ul
ld
d
a
al
lw
wa
ay
ys
s
b
be
e
r
re
ep
pl
la
ac
ce
ed
d
w wh
he
en
n
r
re
ep
pa
ai
ir
rs
s
a
ar
re
e
p
pe
er
rf
fo
or
rm
me
ed
d.
.
The lower part of the timing chain housing is
bolted to the cylinder head using two M8x45
bolts.
Camshafts
The camshafts are made from chilled cast iron
and are hollowed to reduce weight. The cam-
shafts are weighted with counterbalances for
equalizing imbalances in the valve gear.
1. Camshaft sensor wheels (sintered metal)
2. Thrust bearing area with oil ducts for the
VANOS units
N No
ot
te
es
s:
:



22
N62 Engine
42-02-23
42-02-22
42-02-24

Downloaded from www.Manualslib.com manuals search engine 30
N62 Engine
Camshaft Sensors
The cam shaft sensors (Hall effect) are mounted through the cylinder head cover. There are
two sensors per cylinder head to monitor the intake and exhaust camshaft positions.
The sensors monitor the impulse wheels
attached to the ends of the camshafts.
Solenoid Valves
The VANOS solenoid valves are mounted through the upper timing case front cover. There
are two solenoids per cylinder head to control the oil flow to the camshaft ports for the
intake and exhaust VANOS units.
The 4/3 way proportional solenoid valve is acti-
vated by the ECM to direct oil flow. The sole-
noid valve is sealed to the front cover by a radi-
al seal and secured by a retaining plate.
N No
ot
te
es
s:
:

42-02-48 Camshaft Sensors
1. Valvetronic Position Sensor
2. Intake Camshaft Position Sensor
3. Exhaust Camshaft Position Sensor
42-02-42

Downloaded from www.Manualslib.com manuals search engine 31
N62 Engine
VANOS Sectional Views
M Me
ec
ch
ha
an
ni
ic
ca
al
l
L
La
ay
yo
ou
ut
t:
:
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

Downloaded from www.Manualslib.com manuals search engine 32
N62 Engine
H Hy
yd
dr
ra
au
ul
li
ic
c
A
Ac
ct
tu
ua
at
ti
io
on
n:
:
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
dj
ju
us
st
tm
me
en
nt
t
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

Downloaded from www.Manualslib.com manuals search engine 33
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
es
se
et
t
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).
N No
ot
te
es
s:
:

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