valve BMW 745i 2002 E65 N62B44 Engine User Guide

Downloaded from www.Manualslib.com manuals search engine Crankcase Venting System
The crankcase vapors (a result of combustion blow-by gasses) are led out of the crank-
case and back into the combustion chamber via the intake manifold. The blow-by gasses
contain droplets of oil which must be separated. The oil is returned to the sump while the
blow-by gasses are led into the intake pipe for combustion.
The engine performance is affected by the introduction of crankcase vapors into the com-
bustion process, particularly in idle speed ranges. This influence is monitored by lambda
regulation.
The crankcase vapors are carried from the crankcase and into the cylinder head covers
through labyrinth separators (one per cylinder head). The oil which accumulates on the
walls of the labyrinth separators flows into the cylinder head via a siphon and from there
back to the sump.
The remaining vapors are passed to the engine for combustion via the pressure control
valve (5) in the intake manifold. One labyrinth separator with a pressure control valve is inte-
grated in each of the two cylinder head covers.
The throttle valve is controlled so that there is always a 50 mbar vacuum in the intake man-
ifold. The pressure control valve regulates the crankcase pressure to a low 0-30 mbar.
12
N62 Engine
43-02-12 Cylinder Head Cover
1-4. Opening for Spark Plugs
5. Pressure Control Valve
6. Opening Valvetronic Motor
7. Opening Valvetronic Sensor
Connector
8. Camshaft Sensor

Downloaded from www.Manualslib.com manuals search engine Silencers
• A 1.8 liter capacity front silencer has been fitted for each cylinder bank.
• A single 5.8 liter center silencer is fitted downstream of the two front silencers.
• The resonator type rear silencers have capacities of 12.6 and 16.6 liters.
Exhaust Gas Flap
The 12.6 liter rear silencer is fitted with an exhaust gas flap to keep noise to a minimum at
engine idle speed and low rpm. The exhaust gas flap is opened allowing additional flow
when:
• The a transmission gear is engaged a an
nd
d
• The engine speed is above 1,500 rpm
A vacuum-controlled diaphragm (actuator mounted on the silencer) opens and closes the
exhaust gas flap. The exhaust gas flap is closed with vacuum, and is sprung open by the
actuator (when vacuum is not present). The procedure is carried out using a solenoid valve
which is electrically controlled by the ECM.
Secondary Air System
Blowing additional air (secondary air) into the cylinder head exhaust ducts during the warm-
up phase results in a thermal secondary combustion which results in a reduction of the
non-combusted hydrocarbons (HC) and carbon monoxide (CO) in the exhaust gas. The
energy generated during this process heats up the catalytic converter faster during the
warm-up phase, and increases it’s conversion rate.
14
N62 Engine
43-02-05
Secondary Air System
1. Air Intake Duct
2. Air Cleaner housing with Intake Air Silencer
3. Intake Pipe with HFM (Hot-Film Air-Mass
Sensor)
4. Non-return Valves
5. Secondary Air Pump

Downloaded from www.Manualslib.com manuals search engine Secondary Air Pump (SLP)
The electrically-operated secondary air pump is mounted to the vehicle body. The pump
draws out filtered fresh air from the air cleaner housing during the warm-up phase and sup-
plies it to the two secondary air Non-return Valves.
Once the engine has been started, the secondary air pump is supplied with voltage by the
ECM via the secondary air pump relay. It remains switched on until the engine has taken in
a certain amount of air.
The O ON
N
period may be a maximum of 90 seconds and it depends on the following engine
operating conditions:
• Coolant temperature (from -10 ºC to approximately 60 ºC)
• Air temperature (NTC sensor in HFM)
• Engine speed
One non-return valve is mounted on each cylinder head (see also Engine Views).
The non-return valves are opened by the pressure generated from the secondary air pump.
The secondary air is led through a pipe to the secondary air ducts (integral in the cylinder
heads) for distribution into the exhaust ports.
The non-return valves are sprung closed when the secondary air pump is deactivated. This
prevents exhaust vapors, pressure and condensation from flowing back into the secondary
air pump.
15
N62 Engine
43-02-14
View From Rear of The Cylinder Head
1. Cylinder Head Lead
2. Non-return Valve (SLV)
3. Secondary Air Pump Connection

Downloaded from www.Manualslib.com manuals search engine The ECM takes on the following functions:
• Activation/deactivation of the alternator.
• Informing the alternator regulator of the nominal voltage value to be set.
• Controlling the alternator's response to load.
• Diagnosing the data line between the alternator and the ECM.
• Storing alternator fault codes.
• Activating the charge indicator lamp in the instrument cluster.
The connection with the ECM makes it possible to equalize the alternator load torque for
nearly all operating conditions. This supports the engine idling speed control and the bat-
tery load balance. In addition, the ECM receives information from the Power Module about
the battery's calculated temperature and charge status. This means that alternator output
can be adapted precisely to the temperature and load status of the battery which increas-
es the battery service life.
The charge indicator display strategy has not changed in comparison with the alternators
currently in use. Regulating the alternator output is particularly important when activating
Valvetronic operating motors.
A temperature protection function is implemented in the voltage regulator. If the alternator
overheats, the alternator voltage is reduced until an appropriate temperature has been
reached.
T Th
he
e
E
EC
CM
M
c
ca
an
n
r
re
ec
co
og
gn
ni
iz
ze
e
t
th
he
e
f
fo
ol
ll
lo
ow
wi
in
ng
g
f
fa
au
ul
lt
ts
s:
:
• Mechanical faults such as blockages or belt drive failure.
• Electrical faults such as exciter diode defects or over/under voltage caused by regula-
tion defects.
• Connection defects between the ECM and the alternator.
C Co
oi
il
l
b
br
re
ea
ak
ks
s
a
an
nd
d
s
sh
ho
or
rt
t-
-c
ci
ir
rc
cu
ui
it
ts
s
c
ca
an
nn
no
ot
t
b
be
e
r
re
ec
co
og
gn
ni
iz
ze
ed
d.
.
T
Th
he
e
b
ba
as
si
ic
c
a
al
lt
te
er
rn
na
at
to
or
r
f
fu
un
nc
ct
ti
io
on
n
i
is
s
i
in
n
o op
pe
er
ra
at
ti
io
on
n
e
ev
ve
en
n
i
if
f
t
th
he
e
B
BS
SD
D
i
in
nt
te
er
rf
fa
ac
ce
e
f
fa
ai
il
ls
s.
.
18
N62 Engine

Downloaded from www.Manualslib.com manuals search engine N No
ot
te
e:
:

The alternator regulator voltage is influenced by the ECM - BSD interface. The bat-
tery charge voltage can therefore be up to 15.5 V, depending on the battery temperature.
If a battery charge voltage of up to 15.5 V is measured, the regulator is not faulty. A high
charge voltage indicates a low battery temperature.
Air Conditioning Compressor
The “clutch free” A/C compressor is manufac-
tured by Denso. It functions continuously with
the engine running. The compressor is a 7-
cylinder swash plate type. The displacement
can be reduced to less than 3% when air con-
ditioning is not requested (no refrigerant is sup-
plied to the refrigerant circuit).
There is an internal compressor refrigerant cir-
cuit to maintain lubrication. The IHKA electron-
ics regulate the compressor output via an
external control valve (1).
Starter Motor
The starter motor is located on the right-hand
side of the engine below the exhaust manifold,
and is a compact planetary drive starter with a
1.8 kW output.
1. Starter motor with heat protective cover.
Power Steering Pump
The power steering pump is a tandem radial piston pump on vehicles equipped with
Dynamic Drive. A single vane pump is installed on vehicles without the Dynamic Drive.
Further information about the power steering pump can be found in the Chassis Dynamics
section.
19
N62 Engine
42-02-19
42-02-03

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 Engine Covers
Each cylinder head has a plastic cover for the ignition coil cabling and top of the cylinder
head. The covers “push fit” into rubber grommets on the cylinder head covers.
A sound absorption cover for the top of the
engine also covers the two Valvetronic motors.
This cover is fixed to the intake manifold hous-
ing using four bolts.
The cylinder head covers are made from plastic. The retaining sleeves for the ignition coils
have molded-on gaskets. The sleeves must be replaced if any hardening or damage is vis-
ible on the gaskets. The sleeves are inserted into the cylinder head through the cylinder
head cover (nos. 1through 4).
N No
ot
te
es
s:
:

21
N62 Engine
42-02-21
Engine Covers
Cylinder Head Cover
1. Cylinder Head Top Cover
2. Sound Absorption Engine Cover
1-4. Opening for Spark Plugs
5. Pressure Control Valve
6. Opening for Valvetronic Motor
7. Opening for Valvetronic Sensor Connector
8. Camshaft Sensors (Intake and Exhaust)
43-02-12

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 Valvetronic
Over the entire speed and load range, the gasoline engine needs a combustible fuel-air
mixture within the ideal ratio (Lambda = 1). The mixture quantity must be altered to vary the
speed and output. This variation is effected by the throttle valve. The mixture, which falls
within the narrow range of Lambda = 1, is formed outside the combustion chamber using
the fuel injection system (external mixture formation).
The mixture control is influenced by the throttle valve and is not optimal in all the different
load ranges. This is particularly true in the idle to part-load ranges, since the throttle valve
is only opened slightly in these ranges. The consequences are less than optimal cylinder
filling, torque and increased fuel consumption.
Technical measures were previously introduced; such as the optimization of air/fuel mixing,
improved valve overlap, introduction of DISA and the steady improvement of mixture con-
trol all depend on the throttle valve. This is where the new completely unique Valvetronic
design comes in.
The Valvetronic system simultaneously varies the valve opening time and the valve opening
lift between 0.3 mm and 9.85 mm, according to engine speed and load. This means that
the air/fuel mixture volume is controlled according to engine requirements. This type of mix-
ture and volume control makes the typical throttle valve control unnecessary.
23
N62 Engine

Downloaded from www.Manualslib.com manuals search engine Physical considerations:
On engines with throttle valve control, the throttle valve is slightly open in the idling and part-
load ranges. This results in the formation of up to 500 mbar vacuum in the intake manifold,
which prevents the engine from aspirating freely and in turn prevents optimum cylinder fill-
ing. The Valvetronic system with an open throttle valve largely counteracts this disadvan-
tage. The air-mass flow to the intake valves is unrestricted. The full ambient pressure is
available directly at the intake valves for cylinder filling and scavenging.
The Valvetronic system primarily controls the fill by adapting the valve opening time and the
valve lift (short opening time/small valve lift = lower fill, and vice versa). During the valve
opening phase the engine aspirates more freely via the intake valves even with small valve
lifts vs. a throttle valve which is continuously blocked.
The slower cylinder filling from the intake valves with partial lift results in more turbulence in
the combustion chamber, thus faster and better mixture control and more efficient com-
bustion. At lower engine speeds this effect is intensified by opening the intake valves later,
after top dead center (ATDC) using VANOS. This increases vacuum in the combustion
chamber which accelerates filling and turbulence when the intake valves are opened.
I In
n
s
su
um
mm
ma
ar
ry
y,
,
the additional variability of the Valvetronic system results in optimization of
cylinder filling and scavenging throughout the engine's entire operating range. This has a
positive effect on output, torque and a decrease in fuel consumption and exhaust emis-
sions.
F Fe
ea
at
tu
ur
re
es
s:
:
• Valve lift adjustment
• VANOS for intake and outlet
• Variable intake manifold
• Mixture control and ignition control
• Other individual engine design measures
T Th
hi
is
s
r
re
es
su
ul
lt
ts
s
i
in
n:
:
• Improved engine idling
• Improved engine torque
• Improved engine torque curve
• Fewer pollutant emissions
T Th
he
es
se
e
b
be
en
ne
ef
fi
it
ts
s
r
re
es
su
ul
lt
t
i
in
n
a
a
c
cl
le
ea
ar
r
i
im
mp
pr
ro
ov
ve
em
me
en
nt
t
i
in
n
p
pe
er
rf
fo
or
rm
ma
an
nc
ce
e
a
an
nd
d
f
fu
ue
el
l
c
co
on
ns
su
um
mp
pt
ti
io
on
n
r
re
ed
du
uc
c-
-
t ti
io
on
n
(
(1
14
4%
%)
)
f
fo
or
r
t
th
he
e
d
dr
ri
iv
ve
er
r.
.
24
N62 Engine
T Th
he
e
m
ma
ai
in
n
b
be
en
ne
ef
fi
it
ts
s
o
of
f
t
th
he
es
se
e
f
fe
ea
at
tu
ur
re
es
s
a
ar
re
e:
:
• Improved cylinder filling with air/fuel mix-
ture
• Improved mixture control before the cylin-
der inlet
• Improved combustion procedure