Code 21 BMW 328i 1998 E36 User Guide
Page 54 of 759
100-
1
2
ENGINE-GENERAL
NOTE-
The
oxygen
sensor
signal
is
ignored
until
the
engine
reachesa
specified
minimum
temperature
.
Therefore,
The
primary
input
usedby
the
fuel
injection
system
to
deter-
when
troubleshooting
cold
engine
driveability
prob-
mine
how
much
fuel
should
be
delivered
is
the
signal
from
the
lems,
the
oxygensensor
canbe
ruled
out
asa
possible
mass
air
flow
sensor
in
the
intake
air
ductwork
.
cause
.
As
the
oxygen
sensor
ages,
its
ability
to
react
quickly
to
changing
conditions
deteriorates,
and
it
may
eventually
cease
to
produce
any
signal
at
all
.
To
check
the
operation
of
the
oxy-
gen
sensor,
see
130
Fuel
Injection
:
NOTE-
On
1996
and
latercars,
OBD
11
enhanced
emission
standards
require
the
engine
control
module
(ECM)
to
monitor
the
oxygen
content
in
the
exhaust
both
before
and
after
the
catalytic
converter
.
Thisallows
for
tighter
control
of
the
tail
pipe
emissions
and
also
allowsthe
ECM
to
diagnose
converter
problems
.
If
the
DME
de-
tects
that
catalytic
converter
or
oxygensensor
efficien-
cyhas
degraded
pasta
certain
pre-programmed
limit,
it
will
turn
on
the
Check
Engine
light,
and
store
a
diag-
nostic
trouble
code
(DTC)
in
the
ECM
.
DRIVEABILITY
TROUBLESHOOTING
Catalytic
B9506
Air
Flow
Measurement
and
Vacuum
Leaks
Because
proper
fuel
metering
depends
on
accurate
mea-
surement
of
the
incoming
air,
any
unmeasured
air
that
enters
the
engine
downstream
of
the
mass
air
flow
sensor
will
cause
a
lean
air-fuel
mixture
and
possibly
affectdriveability
.
NOTE-
Fig
.
10
.
Regulating
oxygen
sensor
measures
oxygen
content
of
ex-
gattery
Voltage
hausY
gas
as
indicator
of
.¡_fi
.1
ratio
and
"-k,
.
E-
effi-
ciency
.
Monitoríng
oxygen
sensor
(not
shown)
monitors
If
a
large
air
leak
is
causing
driveability
problems,
the
Check
Engine
light
will
usually
be
illuminated
and
a
fault
will
be
stored
in
the
fault
code
memory
.
See
On
Board
Diagnostics
(OBD)
.
There
are
many
places
for
unmeasured
air
to
enter
theen-
gine
.
First,
inspect
all
hoses,
fittings,
ducts,
seals,
and
gaskets
in
the
intake
air
tract
for
cracks
or
looseness
.
It
may
be
neces-
sary
to
remove
parts
that
cannot
be
fully
checked
in
their
in-
stalled
positions
.
Also
make
sure
all
of
the
intake
manifold
and
throttle
body
mounting
nuts
are
tight
.
In
addition
to
air
leaks,
air
restrictions
can
also
cause
drive-
ability
problems
.
Remove
the
air
filter
and
hold
it
up
to
a
strong
light
source
.
If
the
filter
does
not
pass
light,
it
is
restricted
and
should
be
replaced
.
Also,
remove
the
intake
air
ductwork
and
check
for
oily
deposits
at
the
throttle
plate
.
Buildup
in
this
area
can
cause
an
erratic
idle
.
Clean
away
any
deposits
using
a
cloth
wetted
withcarburetor
cleaner
and
reinstall
the
ductwork
.
CAUTION-
Do
not
spray
carburetor
cleaner
directly
in
the
throt-
tle
anea
.
Spraying
cleaner
may
force
it
into
the
throt-
tle
position
switch
or
sensor
and
cause
damage
.
catalytic
converter
operation
.
All
of
the
electrical
components
in
the
fuelinjection
and
igni-
tion
systems
require
a
minimum
voltage
to
operate
properly
.
When
troubleshooting
engine
driveability
problems,
one
of
Replacement
of
oxygensensors
at
the
specified
intenrals
en-
the
first
checks
should
be
to
make
sure
the
battery
is
fully
sures
that
the
engine
and
emission
control
system
wili
continue
charged
and
capable
of
delivering
allits
power
to
the
electricalto
operate
as
designed
.
As
the
oxygen
sensor
ages,
its
ability
to
system
.
react
quickly
to
changing
conditions
deteriorates,
and
it
may
eventually
cease
to
produceany
signal
at
all
.
To
make
a
quick
check
of
battery
charge,
measure
the
volt-
age
across
the
battery
terminals
with
all
cables
attached
and
As
the
oxygen
sensor
ages,
its
ability
to
react
quickly
to
the
ignition
off
.
A
fully
charged
battery
will
measure
12
.6
volts
changing
conditions
deteriorates,
and
it
may
eventually
cease
or
slightly
more,
compared
to
12
.15
volts
for
a
battery
with
a
to
produce
any
signal
at
all
.
To
check
theoperation
of
the
oxy-
25%
charge
.
gen
sensor,
see130
Fuel
Injection
.
Even
a
fully
charged
battery
cannot
deliver
power
unless
it
is
properly
connected
to
the
electrical
system
.
Check
the
bat-
tery
terminals
for
corrosion
and
loosecableconnections
.
If
the
battery
does
not
maintain
the
proper
voltage,
the
charging
system
may
be
atfault
.
See
121
Battery,
Starter,
Alternator
.
Page 59 of 759
110
Engine
Removal
and
Installation
GENERAL
.
.
.
.
.......
.
.
.
..........
.
...
110-1
Engine,
removing
and
installing
(4-cylinder
engines)
.
..
.....
..
...........
110-1
ENGINE
REMOVAL
AND
INSTALLATION
110-1
Engine,
removing
and
installing
(6-cylinder
engines)
..
...
...
..
.....
..
....
110-4
GENERAL
Some
special
tools
are
required
for
removal
and
installation
of
the
engine
.
Be
sure
to
have
the
necessary
equipment
on
hand
before
starting
thejob
.
CAUTION-
"
Engine
removal
requires
disconnecting
the
bat-
tery
.
This
may
erase
any
system
fault
code(s)
that
havebeen
stored
in
control
unit
memories
.
Check
forfault
codes
prior
to
disconnecting
the
battery
cables
.
"
If
the
Check
Engine
lightis
illuminated
with
the
engine
running,
see
100
Engine-General
for
On-Board
Diagnostics
(08D)
fault
code
infor-
mation
.
"
If
any
other
system
faults
have
been
detected,
as
indicated
by
an
illuminated
ANTI
LOCK,
SRS
or
AST
warning
light,
see
the
appropriate
repair
group
inthis
manual
or
an
authorized
BMW
dealer
for
more
information
on
fault
codes
.
ENGINE
REMOVALAND
INSTALLATION
Engine,
removing
and
installing
(4-cylinder
engines)
Cover
al¡
painted
surfaces
before
beginning
theremoval
procedure
.
Asan
aid
to
installation,
label
al¡
components,
wires,
and
hoses
before
removing
them
.
Do
not
reuse
gas-
kets,
O-rings
or
seals
during
reassembly
.
WARNING
-
Due
to
risk
of
personal
injury,
be
sure
the
engine
is
cold
before
beginning
the
removalprocedure
.
1.
Disconnect
negative
(-)
cable
from
battery
in
luggage
compartment
.
0011969
CAUTION-
Prior
to
disconnecting
the
battery,
read
the
battery
disconnection
cautions
given
at
the
front
of
this
manual
on
page
viii
.
ENGINE
REMOVAL
AND
INSTALLATION
110-1
2
.
Remove
transmission
from
car
.
See230
Manual
Transmission
or
240
Automatic
Transmission
.
3
.
Remove
enginehood
or
place
hood
in
service
positíon
.
See
410
Fenders,
Engine
Hood
.
NOTE-
tt
is
notnecessary
to
remove
the
engine
hood,
but
it
is
helpful
and
will
make
engine
removal
and
installation
easier
.
4
.
Remove
splash
guard
under
engine,
if
applicable
.
5
.
Unbolt
ignition
coil
assembly
from
bracket
on
strut
tow-er
.
Disconnect
wiring
to
ignition
cofs,
then
place
coil
assembly
on
engine
.
6
.
Disconnect
al¡
cables
and
harness
connectors
at
throt-
tle
housing
.
7
.
Unbolt
andremove
complete
air
cleaner
housing
with
mass
air
flow
sensor,
disconnecting
and
labeling
con-
nectors,
ducting
and
hoses
asnecessary
.
See
Fig
.
1
.
Fig
.
1
.
Intake
air
duct
hose
clamp
(A),
mass
air
flow
sensor
connec-
tor
(B),
and
air
cleanerto
air
flow
sensor
clips
(C)
on
M44
en-
gine
.
ENGINE
REMOVAL
AND
INSTALLATION
Page 67 of 759
113
Cylinder
Head
Removal
and
Installation
GENERAL
.
...............
.
.
.
.
.
.......
113-1
CYLINDER
HEAD,
6-CYLINDER
.
.
.
.
.
.
.
113-10
Cylinder
head,
removing
(6-cylinder
engine)
..
113-10
CYLINDER
HEAD,
4-CYLINDER
..
.
...
.
.
113-1
Cylinder
head,
installing
(6-cylinder
engine)
...
113-15
Cylinder
head,
removing
(4-cylinder
engine)
...
113-1
E
Cylinder
head,
installing
(4-cylinder
engine)
...
113-6
GENERAL
CYLINDER
HEAD,
4-CYLINDER
The
information
given
inthis
repair
group
assumes
that
the
engine
is
installed
in
the
engine
bay
.
For
cylinder
head,
cam-
Cylinder
head,
removing
shaft,
and
valvetrain
disassembly
and
reconditioning
informa-
(4-cylinder
engine)
tion,
see116
Cylinder
Head
and
Valvetrain
.
For
ease
of
use
this
removal
procedure
is
broken
into
sub-
In
the
procedures
given
below,
engines
are
referred
to
by
sections,
as
follows
:
engine
code
.
If
necessary,
see100
Engine-General
for
en-
gine
code
and
application
information
.
NOTE-
If
a
head
gasket
problem
is
suspected,
acompression
test
will
usually
detectthe
fault
.
See
100
Engine-Gen-
eral
for
compression
testing
information
.
Special
BMW
service
tools
are
required
to
properly
remove
and
install
the
cylinder
head
on
both
the
4-cylinder
and
6-cyl-
inder
engines
.
The
special
tools
are
used
to
time
the
val-
vetrain
to
the
crankshaft
and
to
remove
the
Torx
(El
2)
head
bolts
.
Read
the
procedure
through
before
beginning
thejob
.
Cover
al¡
painted
surfaces
before
beginning
the
removal
procedure
.
As
an
aid
to
installation,
label
all
components,
wires,
and
hoses
before
removing
them
.
Do
not
reuse
gas-
kets,
O-rings
or
seals
during
reassembly
.
WARNING
-
Due
to
risk
of
personal
injury,
be
sure
the
engine
is
cold
before
beginning
the
removalprocedure
.
CYLINDER
HEAD
REMOVAL
AND
INSTALLATION
113-1
General
Coolingsystem,
draining
Cylinder
head
cover,
removing
Intake
manifold,
removing
Timing
chains,
uncoupling
Cylinder
head
assembly,
removing
WARNING
-
Allow
engine
to
cool
before
beginning
this
proce-
dure
.
General
1
.
Disconnect
negative
(-)
cable
from
battery
.
CAUTION
-
"
Prior
to
disconnectiog
the
battery,
read
the
bat-
tery
disconnection
cautions
given
at
the
front
of
this
manual
on
page
viii
.
"
Disconnecting
the
battery
may
erase
fault
codees)
stored
in
control
module
memory
.
Check
for
fault
codes
using
special
BMW
diagnostic
equipment
.
NOTE-
The
battery
is
mounted
in
the
luggage
compartment
behind
the
right
side
trim
panel
.
2
.
Working
underneath
vehicle,
remove
front
exhaust
pipe
from
exhaust
manifold
.
See
Fig
.
1
.
3
.
Disconnect
vacuum
hose
fitting
from
brake
booster
on
rear
bulkhead
.
Plug
opening
in
booster
and
hose
end
.
CYLINDER
HEAD,
4-CYLINDER
Page 76 of 759
113-10
CYLINDER
HEAD
REMOVAL
AND
INSTALLATION
Tightening
Torques
"
Coolant
drain
plug
to
cylinder
block
.
.
25
Nm
(18
ft-1b)
"
Intake
manifold
support
to
manifold
.
.
15
Nm
(11
ft-Ib)
"
Lower
intake
manifold
to
cylinder
head
.
..........
.
..
...
15
Nm
(11
ft-Ib)
"
Lower
intake
manifold
to
upper
manifold
..........
.
..
...
15
Nm
(11
ft-Ib)
"
Radiator
cooling
fan
to
coolant
pump
.
40
Nm
(30
ft-Ib)
"
Radiator
drain
screw
to
radiator
...
.
2
.5
Nm
(22
in-lb)
CYLINDER
HEAD,
6-CYLINDER
For
ease
of
use
this
procedure
is
broken
into
subsections,
as
follows
:
General
Coolingsystem,
draining
Cyiinder
head
cover,
removing
Intake
manifold,
removing
Timing
chains,
uncoupling
Cylinder
head
assembly,
removing
WARNING
-
Allow
the
engine
to
cool
before
beginning
this
pro-
cedure
.
General
1
.
Working
inside
luggage
compartment,
disconnect
neg-
ative
(-)
battery
cable
.
CAUTION-
"
Prior
to
disconnectiog
the
battery,
read
the
bat-
tery
disconnection
cautions
given
at
the
front
of
this
manual
on
page
vi¡¡
.
"
Disconnecting
the
battery
may
erase
fault
code(s)
stored
in
control
module
memory
.
Check
for
fault
codes
using
special
BMW
diagnostic
equipment
2
.
Remove
front
exhaust
pipes
from
manifolds
.
Discard
nuts
.
3
.
Remove
air
filter
housing
complete
with
mass
air
flow
sensor
and
intake
air
ducting
.
Disconnect
vacuum
hos-
es
from
throttle
housing
.
4
.
On
M52
and
S52US
engines
:
Remove
secondary
air
injection
check-valve
from
front
of
engine
and
set
aside
.
CYLINDER
HEAD,
6-CYLINDER
Coolingsystem,
draining
5
.
Drain
engine
coolant
and
Rmove
coolant
hoses
from
thermostat
housing
.
Drain
engine
block
by
removing
block
drain
.
See
170
Radiator
and
Cooling
System
.
NOTE-
The
block
drain
is
on
the
exhaust
side
of
the
engine,
near
cylinder
no
.
5
.
6
.
Remove
radiator
cooling
fan
and
fan
shroud
.
See
170
Radiator
and
Cooling
System
.
NOTE-
The
radiator
cooling
fannut(32
mm
wrench)
has
left-
hand
threads
.
Cylinder
head,
removing
(6-cylinder
engine)
7
.
Disconnect
heater
hoses
at
rear
of
cylinder
head
.
See
Fig
.
26
.
'i
8
.
Remove
alternator
cooling
duct
.
Cylinder
head
cover,
removing
0012687
Fig
.
26
.
Disconnect
heater
hoses
at
heater
valve
(A)
and
heater
core
(B)
.
9
.
Remove
air
plenum
from
rear
of
engine
compartment
.
See640
Heating
and
Air
Conditioning
.
10
.
Remove
plastic
cylinder
head
covers
from
above
fuel
injectors
and
ignition
coils
.
Pull
larger
cover
forward
when
removing
.
See
Fig
.
27
.
11
.
Disconnect
crankcase
ventílation
hose
fitting
from
cyl-
inder
head
cover
.
12
.
Disconnect
ignition
coil
harness
connectors
from
coiis
.
Remove
ignition
coiis
and
spark
plugs
.
See
120
Igni-
tion
System
.
Page 85 of 759
GENERAL
CYLINDER
HEAD,
DISASSEMBLY
AND
ASSEMBLY
CYLINDER
HEAD
AND
VALVETRAIN
116-1
116
Cylinder
Head
and
Valvetrai
n
GENERAL
.
.....
.
.
.
...
.
.
.
.
.
.
.
.
.
.......
116-1
Hydraulic
cam
followers,
checking
and
replacing
(M42
and
al¡
6-cylinder
engines)
.
...
.....
.
..
116-9
CYLINDER
HEAD,
Valve
guides
.
.
.
...
.
.
.
.
.
.
...
.
.
.
.
.
.
.
.
.
.
116-10
DISASSEMBLY
AND
ASSEMBLY
...
.
...
116-1
Valves
.
.
.
.
.
.
.
.
.
.
.
.
.
...
.
...
.
.
.
.
.
...
.
.
116-11
Camshafts,
removing
and
installing
(M42
engine)
....
.
....
.
.
.
.
.
.
.
.
.
.....
.
.
116-1
Valves,
leak
test
.
.
.
.
.
.
.
.
.
.
...
.
.
.
.
.
.
.
.
.
.
116-11
Camshafts,
removing
and
installing
Valve
stem
oil
seals
.
.
.
.......
.
.
.
.
.
...
.
.
116-11
(M44
engine)
.........
.
.
.
.
.
.
.
.
.
.......
116-3
Valve
seats
.
.
.
.
.
.
.
.
.
...
.
...
.
.
.
.
.
...
.
.116-12
Camshafts,
removing
and
installing
Valve
springs
.
.
.
.
.
.
.
.
...
.
...
.
.
.
.
.
.....
116-12
(6-cylinder
engine)
.....
.
.
.
.
.
.
.
.
.
.......
116-4
Valves,
removing
and
installing
........
.
....
116-6
TABLES
CYLINDER
HEAD
AND
VALVETRAIN,
a
.
Cylinder
Head
Height
........
....
.
..
..........
116-7
RECONDITIONING
.
...
.
.
.
.
.
.
.
.
.
.......
116-7
b
.
Camshaft
Specifications
.......
..
.
..
........
.116-7
Cylinder
head
...
.
.
.
...
.
.
.
.
.
.
.
.
.
....
.
..
116-7
c
.
Valve
Guide
Specifications
....
...
.
..
........
116-10
d
.
Valve
Specifications
...........
..
.
..
........
116-11
Camshaft
.
.
.
.
.
.
.
.
.
.
.
.
.
.
...
.
.
.
.
.
.......
116-7
e
.
Valve
Seat
Dimensions
.........
.
..
..
......
.116-12
Hydraulic
valve
adjusters,
checking
and
replacing
(M44
engine)
..
.
.
.
116-8
Camshafts,
removing
and
installing
(M42
engine)
This
repair
group
covers
cylinder
head
and
valvetrain
ser-
vice
and
repair
.
Most
of
the
repairs
described
here
require
that
The
camshafts
can
be
removed
with
the
cylinder
head
the
cylinder
head
first
be
removed
as
described
in
113
Cylin-
mounted
on
the
engine
.
The
first
step
is
to
remove
the
cylinder
der
HeadRemoval
and
Installation
.
head
cover
.
See
113
Cylinder
HeadRemoval
and
Installa-
tion
.
NOTE-
Special
BMW
service
tools
should
always
be
used
to
remove
"
For
timing
chain
and
VANOS
repair
information,
see
and
install
the
camshafts
.
Removal
and
installation
of
the
cam-
117
Camshaft
Timing
Chain
.
shafts
without
the
special
tools
can
result
in
camshaft
and
valve
"
If
it
is
determined
that
the
cylinder
head
will
require
train
damage
.
significant
reconditioning
work,
a
remanufactured
cyl-
inder
head
may
bea
good
alternative
.
Remanufac-
WARNING-
tured
cylinder
heads
are
available
froman
authorized
The
process
of
evenly
loosening
the
camshaftbear
BMW
dealer
.
ing
cap
nuts
is
NOT
an
acceptable
method
of
re-
moving
the
camshafts
.
Be
sure
to
read
the
The
information
given
in
this
repair
group
is
organized
ac-
procedure
through
before
starting
the¡ob
.
cording
to
engine
code
.
For
engine
applicationinformation,
see100
Engine-General
.
1
.
Disconnect
negative
(-)
battery
cable
.
CAUTION-
Prior
to
disconnectiog
the
battery,
read
the
battery
disconnection
cautions
given
at
the
front
of
this
manualonpage
viii
.
BMW
special
tools
are
required
for
most
cylinder
head
ser-
2
.
Remove
radiator
cooling
fan
shroud
and
cooling
fan
.
vice
described
in
this
repair
group
.
Many
of
these
tools
areex-
See
170
Radiator
and
Cooling
System
.
pensive
and
only
available
through
an
authorized
BMW
dealer
.
If
the
special
tools
are
not
available,
one
altematve
is
to
remove
the
cylinder
head
and
have
it
disassembled
byan
authorized
CAUTION-
BMW
dealer
.
Be
sure
to
read
each
procedure
thoroughlybefore
Radiator
fa
n
has
left
hand
threads
.
starting
a
job
to
determinewhich
special
tools
and
equipment
will
be
necessary
.
CYLINDER
HEAD,
DISASSEMBLYANDASSEMBLY
Page 86 of 759
116-2
CYLINDER
HEADAND
VALVETRAIN
3
.
Remove
timing
chain
sprockets
and
timing
chains
from
7
.
Slowly
release
pressure
oncamshaft
bearing
capsby
camshafts
.
Remove
upper
timing
chain
guidefrom
cyl-
turningeccentric
shaft
.
Remove
bearing
caps
and
inder
head
.
See117
Camshaft
Timing
Chain
.
camshaft
.
Repeat
procedureon
remaining
camshaft
.
NOTE-
It
is
not
necessary
lo
remove
the
lower
timing
chain
cover
.
4
.
Remove
spark
plugs
and
instaf
BMW
special
tool
11
3
260
to
cylinder
head
.
Tighten
tool
retaining
bolts
in
spark
plug
holes
.
Do
not
over-tighten
bolts
.
See
Fig
.
1
.
6
.
Remove
bearing
cap
mounting
nuts
.
0013033
5
.
Turn
eccentric
shaft
on
special
tool
until
pressure
is
ap-
plied
to
camshaft
bearing
caps
.
See
Fig
.
2
.
Fig
.
2
.
Special
tool
(eccentric
shaft)
being
turned
to
apply
pressure
to
camshaft
bearing
caps
.
CYLINDER
HEAD,
DISASSEMBLYAND
ASSEMBLY
CAUTION-
Camshaft
bearing
caps
mustbe
reinstalled
intheir
original
locations
.
NOTE-
"
The
camshaft
bearing
caps
are
coded
wíth
a
letter
anda
number
.
Forexample,
"Al
"ís
the
exhaust
cam-
shaft
bearing
cap
at
the
front
of
the
engíne,
and
"El"
is
the
intake
camshaft
bearing
cap
at
the
front
of
the
engine
.
"
Camshafts
are
stamped
with
a
code
letter-`E"
for
the
intakeside
and
`A"forthe
exhaust
side
.
"
"E"
isforEinlal3,
(German
for
íntake)
and
A"
isfor
Auspuff,
(German
for
exhaust)
.
"
The
front
of
the
engine
is
at
the
front
of
thecar
.
8
.
Camshaft
installation
is
reverse
of
removal,noting
the
following
:
"
Prior
to
installation,
check
al¡
components
for
wear
as
described
below
underCylinder
Head
and
Va¡-
Fig
.1
.
Special
BMW
tool
no
.
11
3
260
.
Tool
mounting
bolts
(arrows)
vetrain,
Reconditioning
.
thread
into
spark
plug
holes
.
"
Crankshaft
must
be
at
least
45°
away
from
TDC
before
installing
camshafts
to
cylinder
head
.
"
Lubricate
camshafts
prior
to
installation
.
Tightening
Torque
"
Install
camshafts
into
cylinder
head
with
lobes
for
cyl-
"
BMW
special
tool
11
1
260
inder
no
.
1
pointing
up
and
towards
each
other
.
to
cylinder
head
.
...
.
.
...........
23
Nm
(17
ft-Ib)
"
After
installing
camshafts),observe
specified
waiting
time
for
hydraulic
cam
followers
to
fully
compress
be-
fore
bringing
crankshaft
back
to
TDC
.
Page 88 of 759
116-
4
CYLINDER
HEAD
AND
VALVETRAIN
NOTE-
"
The
camshaft
bearing
caps
are
coded
with
a
letter
anda
number
.
Forexample,
'541"is
the
exhaustcam-
shaft
bearing
cap
at
the
front
of
the
engine,
and
`El"
is
the
intake
camshaft
bearing
cap
at
the
front
of
the
engine
.
"
Camshafts
are
stamped
with
a
code
letter-'E"
for
the
intakeside
and
A"
for
the
exhaust
side
.
"
"E"
isfor
Einla3,
(German
for
intake)
and
A"
is
for
Auspuff,
(Germen
for
exhaust)
.
"
The
front
of
the
engine
is
at
the
front
of
the
car
.
8
.
Camshaft
installation
is
reverse
of
removal,
noting
the
following
:
"
Prior
to
installation,
check
all
components
for
wear
as
described
below
underCylinder
Head
and
Val-
vetrain
Reconditioning
.
"
Lubricate
camshafts
prior
to
installation
.
"
Reinstall
timing
chain
sprockets
and
tensioner
and
set
valve
timing
before
reinstalling
rocker
arms,as
spe-
cifically
described
in
117
Camshaft
Timing
Chain
.
"
Be
sure
corresponding
camshaft
lobe
is
pointing
up
before
installing
rocker
arms
.
Note
that
each
rocker
arm
angles
away
from
corresponding
spark
plug
hole
.
See
Fig
.
4
.
"
Wait
at
least
10
minutes
for
hydraulic
cam
followers
to
fully
compress
before
cranking
engine
over
with
start-
er
for
the
first
time
.
Tightening
Torques
"
Camshaft
bearing
caps
to
cylinder
head
(M7)
.............
15
Nm
(11
ft-Ib)
"
Cylinder
head
cover
to
cylinder
head
(M6)
.............
10
Nm
(89
in-lb)
"
Primary
timing
chain
tensioner
plug
to
cylinder
head
.
................
40
Nm
(30
ft-lb)
(sea
117
Camshaft
Timing
Chain)
"
Spark
plugs
(M12)
.............
...
23
Nm
(17
ft-lb
Timing
chaincover
(upper)
to
cylinder
head
M6
.....
.
.
...
................
.
10
Nm
(7
.5
ft-Ib)
M7
....
..
.
.
........
.
.....
.
...
.
15
Nm
(11
ft-Ib)
"
Timing
chain
sprockets
to
camshaft
M6
....
.
.
..
..............
.
..
..
10
Nm
(7
.5
ft-Ib)
M7
....
....
..............
.
..
..
.15
Nm
(11
ft
.lb)
(sea
117
Camshaft
Timing
Chain)
Camshafts,
removing
and
installing
(6-cylinder
engine)
Camshafts
on
6-cylinder
engines
can
be
removed
with
the
cylinder
head
mounted
on
the
engine
.
The
first
step
is
to
re-
move
the
cylinder
head
cover
.
See
113
Cylinder
Head
Re-
moval
and
Installation
.
CYLINDER
HEAD,
DISASSEMBLYAND
ASSEMBLY
Fig
.
4
.
Correct
installation
position
ofrocker
arms
(arrows)
on
M44
engine
.
Special
BMW
service
tools
should
always
be
used
to
re-
move
and
instan
the
camshafts
.
Removal
of
camshafts
with-
outthe
special
tools
can
result
in
personal
injury
and/or
cylinder
head
damage
.
WARNING
-
The
processof
evenly
loosening
the
camshaft
bear-
ing
cap
nuts
is
NOT
en
acceptable
method
of
re-
moving
the
camshafts
.
Special
tools
shouldalways
be
used
lo
remove
the
camshafts
.
Be
sure
to
read
the
procedure
through
before
starting
ajob
.
1
.
Disconnect
negative
(-)
battery
cable
.
CAUTION-
Prior
to
disconnectiog
the
battery,
read
the
battery
disconnection
cautions
given
at
the
front
of
this
manual
onpaga
viii
.
516
2
.
Setengine
to
TDC
and
lock
into
position
by
installing
BMW
special
tool
11
2
300
through
transmission
bell-
housing
and
into
hole
in
flywheel
or
drive
platea
See
Fig
.
5
.
NOTE-
Arrows
on
camshaft
sprockets
shouldbe
pointing
up
.
Sea
117
Camshaft
Timing
Chain
.
3
.
Remove
VANOS
control
unit
from
cylinder
head
.
Re-
move
timing
chainsprockets
from
camshafts
.
See117
Camshaft
Timing
Chain
.
4
.
Remove
sparkplugs
and
insta¡¡
BMW
special
tool
11
3
260/11
3
270
to
cylinder
head
.
Tighten
tool
retaining
bolts
in
spark
plug
holes
.
Do
not
ovar-tighten
bolts
.
See
Fig
.
6
.
Page 89 of 759
Fig
.
5
.
BMW
special
tool
11
2300
(arrow)
inserted
through
bell-
housing
hole
and
finto
flywheel
.
A
Tightening
Torque
"
BMW
special
tool11
1
260/11
3
270
to
cylinder
head
.................
23
Nm
(17
ft-Ib)
5
.
Remove
intake
camshaft
bearing
cap
no
.
1
.
6
.
Turn
eccentric
shaft
on
special
tool
until
pressure
is
ap-
plied
to
camshaft
bearing
caps
.
See
Fig
.
7
.
7
.
Remove
remaining
bearing
capmounting
nuts
.
CYLINDER
HEAD
AND
VALVETRAIN
116-
5
NOTE-
Fig
.
7
.
Special
tool
(eccentric
shaft)
beingturned
to
apply
pressure
to
camshaft
bearing
caps
.
8
.
Slowly
release
pressure
oncamshaft
bearing
capsby
turning
eccentric
shaft
.
Remove
bearing
caps
and
camshaft
.
Repeat
procedure
on
remaining
camshaft
.
CAUTION-
Camshaft
bearing
capsmust
be
reinstalled
in
their
original
locations
.
"
The
camshaft
bearing
caps
are
coded
with
a
letter
and
a
number
.
For
example,
`A1
"is
the
exhaust
cam-
shaft
bearing
cap
at
the
front
of
the
engine,
and
"E1"
is
the
intake
camshaft
bearing
cap
at
the
front
of
the
engine
.
"
The
camshaftsare
stamped
with
a
code
letter-`E"
for
the
intake
síde
and
`A"
for
the
exhaust
side
.
F19
.6
.
Special
BMW
tool
no
.
11
3260
(A)
with
adapter
ll
3
270
(B)
.
Tool
mounting
bolts
(arrows)
thread
into
spark
plug
holes
.
"
"E"
is
for
Einfal3,
(German
for
intake)
and
`A"
is
for
Auspuff,
(German
for
exhaust)
.
"
The
front
of
the
engine
is
at
the
front
of
the
car
.
CYLINDER
HEAD,
DISASSEMBLYAND
ASSEMBLY
Page 97 of 759
GENERAL
......
.
.
.
.
.
.
.
.
.
...
.
.
.
.
.
.
.
.
.
.
117-1
Camshaft
timing
chains,
removing
(6-cylinder
engines)
....
.
....
..
....
..
...
.117-7
CAMSHAFT
TIMING
CHAIN,
Camshaft
timing
chains,
installing
4-CYLINDER
....
.
.
.
.
.
.
.
.
.
.
.
.......
.
...
117-2
6-clinderen
nes
117-11
Camshaft
timingchain,
removing
(
y
gi
(4-cylinder
engines)
...
..
....
..
...
...
....
117-2
VANOS
(VARIABLE
VALVE
TIMING)
.
..
117-14
Camshaft
timingchain,
installing
VANOS
system
operation,
testing
.....
.
....
117-14
(4-cylinder
engines)
...
..
...
....
..
.
.....
117-4
VANOS
control
unit,
removing
.
..
..........
117-16
CAMSHAFT
TIMINGCHAINS,
VANOS
control
unit,
installing
..
..
..........
117-17
6-CYLINDER
.
.........................
117-6
GENERAL
117
Camshaft
Timing
Chain
This
repair
group
covers
timing
chain
repair
information
for
the
4-
and
6-cylinder
engines
.
4-cylinder
enginesuse
one
double-row
chain
to
drive
the
dual
overhead
camshafts
.
See
Fig
.
1
.
Fig
.
1
.
M44
engine
valvetrain
chain
drive
.
M42
engine
is
similar
.
CAMSHAFT
TIMING
CHAIN
117-1
6-cylinder
enginesusetwo
chains
to
drive
the
camshafts
.
A
primary
chain
is
driven
off
the
crankshaft
and
drives
the
prima-
ry
sprocket
on
the
exhaustcamshaft
.
The
secondary
chain
drives
the
intake
camshaft
.
Each
chain
is
tensioned
by
a
hy-
draulic
tensioner
.
See
Fig
.
2
.
The
timing
chainsare
lubricated
by
engine
oil
and
do
not
re-`
quire
maintenance
.
A
worn
timing
chain
and
sprockets
can
lead
to
noisy
operation
and
erratic
valve
timing
.
A
faulty
ten-
sioner
can
also
cause
timing
chaín
noises
.
Primarychain
NOTE-
See
100
Engine-General
for
engine
code
and
applica-
tion
information
.
Secondary
chain
tensioner
Secondary
chain
B11115
Fig
.
2
.
Cutaway
view
of
camshaft
timing
chains
on1963
and
later
6-
cylinder
engine
with
VANOS
.
GENERAL
Page 103 of 759
Camshaft
timing
chains,
removing
(6-cylinder
engines)
1
.
Disconnect
negative
(-)
cable
from
battery
.
CA
UTION-
Disconnecting
the
battery
may
erase
fault
codes)
stored
in
control
module
memory
.
Check
for
fault
codes
using
special
BMW
diagnostic
equipment
.
2
.
Drain
engine
coolant
.
Drain
engine
block
by
removing
block
drain
.
Remove
radiator
cooling
fan
shroud
and
cooling
fan
.
See170
Radiator
and
Cooling
System
.
.
WARNING
-
Allow
the
engine
to
cool
before
openingor
draining
the
system
.
CAUTION-
Radiator
fan
has
left
hand
threads
.
NOTE-
The
block
drain
plug
is
located
on
the
exhaust
side
of
the
engine,
below
cylinder
no
.
4
.
3
.
Drain
engine
oíl
andremove
oil
pan
.
See
119
Lubrica-
tion
System
.
4
.
Remove
alternator
cooling
duct
.
5
.
Remove
two
large
coolant
hoses
from
thermostat
housing
.
Remove
engine
lifting
bracket
and
thermostat
housing
from
front
of
cylinder
head
.
6
.
Loosen
bolts
for
coolant
pump
pulley
.
Then
remove
drive
belts
for
alternator
andA/C
compressor
.
See
020
Maintenance
Program
.
Remove
coolant
pump
pulley
.
Fig
.
16
.
NOTE-
OnM50
engines
with
a
two-roller
drive
belt
tensioner,
remove
the
upper
rollerto
access
thetensioner
mount-
ing
bolts
.
NOTE-
Make
note
of
the
arrangement
of
the
rubber
insulators
when
removing
the
cylinder
head
cover
mounting
bolts
.
CAMSHAFT
TIMING
CHAIN
117-
7
Fig
.
16
.
Drive
belt
tensioner
mounting
bolts
(arrows)
.
B11055
7
.
Remove
drive
belt
tensioner
from
front
of
engine
.
See
Fig
.
17
.
1992-1995
M50
engine
speed
sensor
on
timing
cover
(ar-
row)
.
10
.
Unclip
andremove
baffle
cover
from
above
intake
cam-
shaft
.
See
Fig
.
18
.
11
.
On
1992
engines
:
Remove
upper
timing
chain
cover
from
front
of
cylinder
head
.
See
Fig
.
19
.
8
.
Remove
engine
speed
sensor
from
lower
timing
chain
12
.
Loosen
spark
plugs
.
See
120
Ignition
System
.
cover,
if
applicable
.
See
Fig
.
17
.
13
.
Set
engine
to
approximate
TDC
by
rotating
in
normal
9
.
Remove
cylinder
head
cover
.
See
113
Cylinder
Head
operating
direction
until
camshaft
lobes
at
cylinder
no
.
Removal
and
Installatíon
.
1
are
facing
each
other
.
See
Fig
.
20
.
14
.
Set
engine
to
TDC
by
aligning
"0/T'
mark
(0°TDC)on
front
vibration
damper
with
cast
bosson
lower
timing
chain
cover
.
See
Fig
.
21
.
15
.
Remove
vibration
damper
mounting
bolts
and
remove
vibration
damper
and
pulley
.
See
Fig
.
22
.
CAMSHAFT
TIMING
CHAINS,
6-CYLINDER