Please
read
these
warnings
and
cautions
before
proceeding
with
maintenance
and
repair
work
.
CAUTION-
"
See
also
Warnings
onpage
vi¡
"
Beforedoing
any
electrical
welding
on
cars
equipped
with
ABS,
disconnect
the
battery
negative
(-)
terminal
(ground
strap)
and
the
"
If
you
lack
the
skills,
tools
and
equipment,
ora
suitable
work-
ABS
control
unit
connector
.
shop
for
any
procedure
described
in
this
manual,
we
suggest
you
leave
such
repairs
to
an
authorized
BMW
dealer
or
other
qualified
"
On
cars
equipped
with
anti-theft
radios,
make
sureyou
know
the
shop
.
correct
radio
activation
code
before
disconnecting
the
battery
or
removing
the
radio
.
lf
the
wrong
code
is
entered
into
the
radio
"
BMW
is
constantly
improving
its
cars
and
sometimes
these
when
power
is
restored,
that
radio
may
lock
up
and
be
renderedchanges,
both
in
parts
and
specifications,
are
made
applicable
to
inoperable,
even
if
the
correct
code
is
thenentered
.
earlier
models
.
Therefore,
part
numbers
listed
in
this
manual
are
for
reference
only
.
Always
check
with
your
authorized
BMW
dealer
"
Always
make
sure
ignition
is
off
before
disconnecting
battery
.
parts
department
for
the
latest
information
.
"
Label
battery
cablesbefore
disconnecting
.
Onsome
models,
"
Before
starting
a
job,
make
certain
that
you
have
all
the
neces-
battery
cablesarenot
color
coded
.
sary
tools
and
parts
on
hand
.
Read
al¡
the
instructions
thoroughly,
do
not
attempt
shortcuts
.
Use
tools
appropriate
to
the
work
and
"
Disconnecting
the
battery
may
erase
fault
code(s)
stored
in
con-
use
only
replacement
parts
meeting
BMW
specifications
.
Make-
trol
module
memory
Using
special
BMW
diagnostíc
equipment,
shift
tools,
parts
and
procedures
will
not
make
good
repairs
.
check
forfault
codes
prior
to
disconnecting
the
battery
cables
.If
the
Check
Engine
light
is
illuminated,
see100
Engine-General
for
"
Use
pneumatic
and
electric
tools
only
to
loosenthreaded
parts
On-Board
Diagnostics
(OBD)
fault
code
information
.
lf
any
other
and
fasteners
.
Never
use
these
tools
to
tighten
fasteners,
espe-
system
faults
have
been
detected
(indicated
by
an
ílluminated
cially
on
light
alloy
parts
.
Always
use
a
torque
wrench
to
tighten
warning
light),
see
an
authorized
BMW
dealer
.
fasteners
to
the
tightening
torque
specification
listed
.
"
If
a
normal
or
rapid
charger
is
used
to
charge
battery,
the
battery
"Be
mindful
of
the
environment
and
ecology
.
Before
you
drain
the
mustbe
disconnected
and
removed
fromthe
vehicle
in
order
to
crankcase,
find
outthe
proper
way
to
dispose
of
the
oil
.
Do
not
avoid
damaging
paint
and
upholstery
pour
oil
onto
the
ground,
down
a
drain,
or
into
a
stream,
pond
orlake
.
Dispose
of
in
accordance
withFederal,
State
and
Local
laws
.
"Do
not
quick-chargethe
battery
(for
boost
starting)
for
longer
than
one
minute
.
Wait
at
least
one
minute
before
boosting
the
bat-
e
If
battery
power
is
lost
or
the
battery
has
been
disconnected,
the
tery
a
second
time
.
powerwindows
must
be
re-initialized
.
Both
one
touch
up/down
and
pinch-protection
will
be
inactive
until
windows
are
re-initial-
"
Connect
and
disconnect
a
battery
charger
only
with
the
battery
ized
.
See
512
Door
Windows
.
charger
switched
off
.
"
The
control
module
for
the
anti-lock
brake
system
(ABS)
cannot
withstand
temperatures
from
a
paint-drying
booth
or
aheat
lamp
in
excess
of
203°F
(95°C)
and
should
not
be
subjected
to
temper-
atures
in
excess
of
185°F
(85°C)
for
more
than
twohours
.
"
Sealed
or
"maintenance
free"
batteries
shouldbeslow-charged
only,
at
anamperage
ratethat
is
approximately
10%
of
the
bat-
tery's
ampere-hour
(Ah)
rating
.
"
Do
not
allow
battery
chargingvoltage
to
exceed
16
.5
volts
.
If
the
battery
begins
producing
gas
or
boiling
violently,
reduce
the
charg-
ing
rate
.
Boosting
a
sulfated
battery
at
a
high
charging
rate
can
cause
an
explosion
.
020-
1
0
MAINTENANCE
PROGRAM
1.
Run
engine
for
afewminutes
to
warm
engine
oil
.
Shut
5
.
When
oil
flow
has
diminished
to
an
occasional
drip,
re-
engine
off
.
install
drain
plugwith
a
new
metal
sealing
washerand
torque
plug
.
2
.
With
car
on
level
ground,
place
drain
pan
under
oil
drain
plug
.
See
Fig
.
5
.
Tightening
Torques
"
Engine
oil
drain
plug
M12
bolt
(17mm
wrench)
.
...
.
..
.
25
Nm
(18
ft-Ib)
-
M22
bolt
(19mm
.
wrench)
...
.
...
.
60
Nm
(44
ft-Ib)
Fig
.
5
.
Engine
oil
drain
plug(arrow)
in
oil
pan
.
3
.
Remove
filter
housingcover
.
Remove
filter
cartridge
and
discard
any
O-rings
.
See
Fig
.
6
.
CAUTION-
Pulí
the
loose
plug
away
from
the
hole
quickly
to
avoidbeing
bumed
by
hot
oil
.
It
wíll
runout
quickly
when
the
plug
ís
removed
.
If
possible,
use
gloves
to
protect
your
hands
.
ENGINE
COMPARTMENT
MAINTENANCE
0012460
Fig
.
6
.
Engine
oil
filter
cartridge
.
Note
O-ring
locations
when
removing
cover
and
filter
.
4
.
Using
a
socket
or
box
wrench,
loosen
drain
plug
at
oil
drain
pan
.
By
hand,
remove
plug
and
letoil
drain
into
pan
.
6
.
Lubricate
and
install
new
O-rings
.
Install
a
new
filter
cartridge
and
housingcover
.
Tighten
cover
.
See
Fig
.
7
.
7
«
a~
.~~
fT~
iII~IIIi~
.
Fig
.
7
.
Oil
flter
housing
on
6-cylínder
engine
.
4-cylinder
engine
is
similar
.
Tightening
Torque
"
Engine
oil
filter
cover
to
oil
filter
housing
...................
25
Nm
(18
ft-Ib)
7
.
Refill
crankcase
with
oil
.'Approximate
oil
capacity
is
list-
ed
in
Tablee
.
Use
dipstick
to
check
correct
oil
level
.
8
.
Start
engine
and
check
that
oil
pressure
warning
light
immediately
goes
out
.
9
.
Allow
engine
to
run
for
a
few
minutes
to
círculate
new
oil,
then
check
for
leaks
at
drain
plug
and
oil
filter
.
Stop
engine
and
reclieck
oil
level
.
ENGINE
COMPAR
ENT
MAINTENANCE
The
information
underthis
heading
describes
routine
mainte-
nance-other
than
oil
change-done
in
the
engine
compart-
ment
.
It
is
not
necessary
for
the
car
to
be
raised
and
supported
off
the
ground
.
Information
on
oil
change
is
given
earlier
under
Engine
Oil
Change
.
GENERAL
.
.....
.
.
.
.
.
.
.
...
.
.
.
.
.
.
.
.
.
...
100-1
Cylinder
Block
and
Crankshaft
.
.
.
.
.
.
.
.
.
...
100-1
Connecting
Rods
and
Pistons
.
.
.
.
.
.
.
.
.
.
.
.
.
100-1
Cylinder
Head
and
Valvetrain
.
.
.
.
.
.
.
.
.
.
.
.
.
100-2
VANOS
(Variable
Valve
Timing)
.
.
.
.
.
.
.
.
...
100-2
DISA
(Dual
Resonance
Intake
System)
.
.
.
.
.
100-3
Engine
Management
System
.
.
.
.
.
.
.
.
.
.
.
.
.
100-3
Ignition
......
.
.
.
.........
.
.
.
.
.
.
.
.
.
.
.
.
100-5
Fuel
Delivery
..
.
.
.
.....
.
...
.
.
.
.
.
.
.
.
.
.
.
.
100-5
Cooling
System
.
...........
.
.
.
.
.
.....
.
.
100-5
Lubrication
System
.........
.
.
.
.
.
.
.
.
.
.
.
.
100-5
MECHANICALTROUBLESHOOTING
.
.
.
.
100-5
Warnings
and
Cautions
..
.
...
.
.
.
.
.
.
.
.
.
.
.
.
100-5
Cylinder
compression,
checking
.
.
.
.
.
.
.
.
.
.
.
100-6
EngineMechanical
Troubleshooting
Table
.
.
.
100-7
DRIVEABILITY
TROUBLESHOOTING
...
100-8
GENERAL
There
are
various
engíne
configurations
used
in
the
1992-
1998
E36
cars
.
See
Table
a
.
On
both
four-
and
6-cylinder
engines,
the
cylinder
block
is
cast
¡ron
with
integral
cyiinders
.
The
cyiinders
are
exposed
on
all
sides
to
circulating
coolant
.
The
fully
counterweighted
crankshaft
rotates
in
replaceable
split-shell
main
bearings
.
Oiiways
drilled
into
the
crankshaft
pro-
vide
bearing
lubrication
.
O¡I
seals
pressed
into
alloy
sea¡
hous-
ings
are
installedat
both
ends
of
the
crankshaft
.
100
Engine-General
Tablea
.
Engine
Specifications
ENGINE-GENERAL
100-1
On-Board
Diagnostics
(OBD)
...
.
.
.
.
.
.
.
.
.
.
.
100-8
Basic
Requirements
....
.
.
.
...
.
.
.
.
.
....
.100-11
Preventive
Maintenance
......
.
.
.
.
.
.....
100-11
Basic
Engine
Settings
..
.
.....
.
.
.
.
.
.....
100-11
Oxygen
Sensors
.
.
.
...
.
.
.
...
.
.
.
.
.
....
.100-11
Air
Flow
Measurement
and
Vacuum
Leaks
.
.100-12
Battery
Voltage
.
.
...........
.
.
.
.
.
.....
100-12
Wiring
and
Harness
Connections
.
.
.
.
.....
100-13
Ground
Connections
...
.
.....
.
.
.
.
.
.....
100-13
Fue¡
Supply
....
.
...........
.
.
..
.....
.100-14
TABLES
a
.
Engine
Specifications
...
...
...........
.
..
..
.100-1
b
.
Engine
Management
Systems
..
..
...........
..
100-5
c
.
Engine
Mechanical
Troubleshooting
..........
.
.
100-8
d
.
OBD
1
Fault
(Blink)
Codes
(1992-1995
models
only)
.
...
..
..
..........
..
.100-9
e
.
Engine
Driveability
Troubleshooting
...........
.100-15
Model
Engine
code
No
.
of
Dispiacement
Compression
Horsepower
cyiinders
liters
(cu
.
in
.)
ratio
SAE
net
@
rpm
318i/is/¡C
1992-1995
M42
4
1
.8
(109
.6)
10
.0
:1
100
@
6000
1996-1998
M44
4
1
.9
(115
.6)
~
10
.0
:1
103
@
6000
323ís/iC
1998
M52
6
2
.5
(152
.2)
10
.5
:1
168
@
5,500
325i/is/iC
1992-1995
M50
6
2
.5
(152
.2)
10
.0
:1
110
@
5,900
328i/is/iC
1996-1998
M52
6
2
.8
(170
.4)
10
.2
:1
190
@
5,300
M3
1995
S50US
6
3
.0
(182
.5)
10
.5:1
240
@
6,000
1996-1998
S52US
6
3
.2
(192
.3)
10
.5:1
240
@
6,000
Cylinder
Block
and
Crankshaft
Connecting
Rods
and
Pistons
The
forged
connecting
rods
use
replaceable
split-shell
bearings
at
the
crankshaft
endand
solid
bushings
at
the
pis-
ton
pin
end
.
The
pistonsare
of
the
three-ring
typewith
two
up-
per
compression
rings
and
a
lowerone-piece
o¡i
scraper
ring
.
Fui¡-floating
piston
pins
are
retained
with
circlips
.
GENERAL
100-6
ENGINE-GENERAL
Cylinder
compression,
checking
A
compression
tester
is
needed
to
make
a
compression
test
.
To
obtain
accurate
test
results,
the
battery
and
starter
must
be
capable
of
cranking
the
engine
at
250-300
rpm,
and
theen-
gine
should
be
at
normal
operating
temperature
.
Use
com-
pressed
air
to
clean
aroundthe
spark
plugs
before
removal
.
1
.
Disable
the
ignítion
system
by
removing
the
engine
management
system
main
relay
and
the
fuel
pump
re-
¡ay
.
See
Fig
.
6
.
WARNING
-
The
ignítion
system
produces
high
voltages
that
canbe
fatal
.
Avoid
contact
with
exposed
termínals
and
useextreme
caution
when
working
on
acar
wíth
the
ignítion
switched
on
or
the
engine
running
.
Fuel
DM
E
pump
main
re
ay
rel
ay
o
oa
ooa
.,
o00
oao
Fig
.
6
.
Engine
management
relays
in
power
distribution
box
inleft
rear
of
engine
compartment
.
CAUTION-
"
On
OBD
11
cars,
making
a
compression
test
may
causea
faultto
set
in
the
ECM
and
may
also
il-
luminate
the
Check
Engine
light
.
The
light
can
only
be
tumed
out
using
special
scan
tool
equip-
ment,using
eíther
the
BMW
specialservíce
tool
or
using
a
"generic"
OBD
11
scan
tool
.
Discon-
necting
the
battery
will
not
erase
the
fault
mem-
orynor
turn
outthe
light
.
0013034,
0012630
Fig
.
7
.
Remove
spark
plug
wires
from
spark
plugs
on
4-cylinder
en-
gine
using
special
tool
.
Tool
is
stored
under
cover
at
rear
of
cylinder
head
(arrow)
.
Fig
.
8
.
Remove
engine
cover
on
6-cylinder
engine
byprying
off
nut
covers
and
removing
nuts
(A)
.
Be
careful
not
to
let
rubber
in-
sulators
fall
off
as
cover
is
removed
(arrows)
.
4
.
On
6-cylinder
engines,
disconnect
the
harness
connec-
tors
from
the
ignítion
coils
by
lifting
the
retaining
clip
.
Remove
the
coil
mounting
nuts
andremove
the
six
coils
.
See
Fig
.
9
.
Remove
the
sparkplugs
.
"
Failure
to
remove
the
main
relay
or
attempting
to
disable
the
ignítion
system
by
other
methods
may
resultin
damage
to
the
engine
control
module
.
NOTE-
Used
sparkplugs
should
be
reinstalled
in
the
same
cyl-
2
.
On
4-cylinder
engine
:
Remove
plastic
engine
cover
from
inder
fromwhich
they
were
removed
.
top
of
cylinder
head
.
Disconnect
spark
plug
wires
and
re-
move
spark
plugs
.
See
Fig
.
7
.
5
.
Insta¡¡
the
compression
gauge
in
the
first
cylinder's
3
.
On
6-cylinder
engine
:
Remove
top
engine
coverby
pry-
spark
plug
hole,
tight
enough
to
form
a
good
seal
.
ing
off
nut
covers
and
removing
mounting
nuts
.
See
Fig
.
8
.
MECHANICAL
TROUBLESHOOTING
eiioo4
Fig
.
9
.
Remove
ignition
coils
on
6-cylinder
engine
by
disconnecting
harness
connector
and
removing
mounting
bolts
(arrows)
.
NOTE-
"
The
compression
gauge
reading
shoutd
increase
with
each
compression
stroke
and
reach
near
its
maxi-
mum
reading
in
about
4-6
strokes
.
"All
cylinders
shoutdreach
maximum
compression
in
the
same
number
of
strokes
.
If
a
cylinder
needs
sig-
nificantly
more
strokes
to
reach
maximum
compres-
sion,
there
is
a
problem
.
7
.
Release
the
pressure
at
the
compression
gauge
valve,
then
remove
the
gauge
from
the
spark
plughole
.
Re-
peat
the
test
for
each
of
the
other
cylinders
and
com-
pare
the
results
with
the
values
given
below
.
ENGINE-GENERAL
1
:00-
7
Compression
Pressure
"
Minimum
..........
.
.
..
..
10-11
bar
(142-156
psi)
"
Maximum
difference
between
cylinders
..
.....
.........
0
.5
bar
(7
psi)
Reinstall
the
spark
plugs
and
spark
plug
wires
or
ignition
cofs
.
The
remainder
of
installation
is
the
reverse
of
removal
.
Be
sure
to
reihstall
al¡
wires
disconnected
during
the
test,
especial-
¡y
ground
wires
at
the
coils
and
cylinder
head
cover
(where
ap-
plicable)
.
Tightening
Torque
"
Spark
plug
to
cylinder
head
.......
25
Nm
(18
ft-Ib)
Low
compression
indicates
a
poorly
sealed
combustion
6
.
With
the
parking
brake
set,
the
transmission
in
Park
or
chamber
.
Relatively
even
pressures
that
are
below
specification
Neutral,
and
the
accelerator
pedal
pressed
to
the
floor,
normally
indicate
worn
piston
rings
and/or
cylinder
walls
.
Erratic
crank
the
engine
with
the
starter
.
Record
the
highest
values
tend
to
indicate
valve
leakage
.
Dramatic
differences
be
value
indicated
by
the
gauge
.
tween
cylinders
are
often
the
sign
of
a
failed
head
gasket,
bumed
valve,
or
broken
piston
ring
.
Engine
Mechanical
Troubleshooting
Table
Table
c
lists
the
symptoms
of
common
engine
mechanical
problems,
their
probable
causes
and
the
suggested
corrective
actions
.
The
bold
type
indicates
the
repair
groups
where
appli-
cable
test
and
repair
procedures
can
befound
.
MECHANICAL
TROUBLESHOOTING
100-8
ENGINE-GENERAL
Symptom
1
Probable
cause
and
correctiveaction
1
.
Engine
will
not
start
or
run
.
Starter
cranks
a
.
No
fuel
reaching
engine
.
Check
forfuelin
tank
.
engine
at
normal
speed
.
Fuel
pump
notoperating
.
Repair
Group
160
b
.
No
spark
.
Check
ignition
system
.
Repair
Group
120
c
.
Incorrect
valve
timing
.
Check
timing
chain
.
Repair
Group
117
2
.
Check
Engine
warning
light
illuminated
.
a
.
DME
engine
management
system
self-diagnostic
fault
detected
.
Sea
an
authorized
BMW
dealer
or
other
qualified
shop
for
OBD
II
fault
code
diagnosis
.
See
also
On-
board
Diagnostics(OBD),
given
later
inthis
repair
group
.
3
.
White
exhaust
smoke
(steam)
.
a
.
Failed
cylinder
head
gasket
(probably
accompanied
bylowcompression
readings)
.
Replace
gasket
and
resurface
cylinder
head
if
necessary
.
Repair
Group
113
4
.
Blue-gray
exhaust
smoke
and
oily
spark
a
.
Contaminated
or
gasoline-diluted
engine
oil
.
Change
engine
oil
and
replace
oil
filter
.
plugs
.
Indicates
oii
burning
in
combustion
.
Repair
Group
020
b
.
Faulty
valve
guide
seals
or
valve
guides
.
Replace
valve
guide
oil
seals
or
overhaul
cylinder
head
.
Repair
Group
116
5
.
Pinging
or
rattling
when
under
load,
a
.
Ignition
timing
too
advanced
.
Ignition
knocksensors
faulty
(CheckEngine
light
traveling
uphill,
or
accelerating,
especially
illuminated)
.
Repair
Group
120fromlow
speeds
.
Indicates
pre-ignition
or
b
.
Fuel
octane
leve¡
toolow
.
detonation
.
c
.
Engine
running
too
hot
or
overheating
.
Check
cooling
system
.
Repair
Group
170
6
.
Light
metallic
tapping
that
varies
directly
with
engine
speed
.
Oil
pressure
warning
light
not
illuminated
.
7
.
Light
metallic
knock
that
varies
directly
with
enginespeed
.
Oil
pressure
warning
light
blinking
or
fully
illuminated
;
may
be
most
noticeable
during
hard
stops
or
cornering
.
8
.
Screeching
or
squealing
under
load
that
a
.
Loose,worn,
or
damaged
drive
belt
.
Inspect
belt(s)
.
Repair
Group
020
goesaway
when
coasting
.
9
.
Growling
or
rumbling
that
varieswith
engine
a
.
Remove
drive
belt(s)toidentifyfaulty
component
.
Check
for
play,
bearing
roughness,
rpm
.
Indicates
abad
bearing
or
bushing
in
and
loose
mountings
.
Refer
to
appropriate
repair
group
for
repair
procedures
.
an
engine-driven
accessory
.
DRIVEABILITY
TROUBLESHOOTING
On-Board
Diagnostics
(OBD)
On-Board
Diagnostics
is
incorporated
into
al¡
engine
man-
Two
generations
of
OBD
are
usedon
thecars
covered
by
agement
systems
used
on
the
cars
covered
by
this
manual
.
this
manual
:
Therefore,
checking
for
fault
codes
should
be
the
first
step
in
troubleshootinga
driveability
problem
.
For
additional
informa-
On-Board
Diagnostics
tion
on
engine
management
and
repair
see130
Fuel
Injec-
tion
.
"
1992-1995models
....
.
..
....
.
..
.......
OBD
I
"
1996-1998models
.
....
..
.
.
.
..
.
........
OBD
II
DRIVEABILITY
TROUBLESHOOTING
Tablec
.
Engine
Mechanical
Troubleshooting
b
.
Warped
or
cracked
cylinder
head
.
Resurface
or
replace
cylinder
head
.
Repair
Group
113
c
.
Cracked
cylinder
block
.
Replace
engine
or
short
block
.
c
.
Worn
piston
rings
.
Overhaul
or
replace
engine
.
d
.
Failed
cylinder
head
gasket
.
Replace
gasket
.
Repair
Group
113
d
.
Air/fuel
mixture
too
lean
(Check
Engine
light
illuminated)
.
Repair
Group
130
a
.
Valveclearances
excessive
.
Check
hydraulic
valve
adjusters
.
Repair
Group
116
b
.
Low
oil
pressure
orpossibly
defective
warning
light
circuit
.
Check
oil
pressure
andwarning
light
circuit
.
Repair
Group
119
c
.
Dirty
oil
.
Change
oil
.
Repair
Group
020
.
a
.
Low
oil
leve¡
.
Check
and
correct
oil
leve¡
.
b
.
Low
oil
pressure/worn
or
faulty
oil
pump
.
Oil
pump
pickup
restricted/clogged
.
Check
oil
pressure
.
Repair
Group
119
The
OBD
system
detects
emissions-related
engine
manage-
ment
malfunctions
and
tucos
on
the
Check
Engíne
lightin
the
in-
strument
cluster
.
TheCheck
Engine
light
will
stay
on
until
the
code(s)are
called
up
and
the
memory
is
erased
.
When
faulty
are
detected,
the
OBD
system
stores
a
Diagnostic
Trouble
Code
(DTC)
in
the
system
ECM
.
In
addition,
the
Check
Engine
warn-
ing
light
will
come
on
if
an
emissions-related
fault
is
detected
.
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
7
.
Lightly
lubricate
new
cylinder
head
bolts
.
Loosely
instan
bolts
and
their
washers,
then
thread
them
in
until
they
are
finger
tight
.
NOTE-
Check
that
all
washers
for
the
cylinder
head
bolts
are
in
place
before
installing
the
bolts
.
8
.
Tighten
cylinder
head
bolts
in
correct
sequence
.
See
Fig
.
17
.
UU125U2
Fig
.
17
.
Cylinder
head
bolt
tightening
sequence
for
4-cylinder
en-
gines
.
Note
oil
supply
tube
seal
(arrow)
on
M44
engine
.
WARNING
-
The
bolts
should
be
tightennd
in
three
stages
as
líst-
ed
below
.
The
final
stages
require
the
use
of
a
spe-
cial
tool
(BMW
tool
No
.
11
2
110)
ora
suitable
protractor
to
tighten
the
bolts
to
a
specified
torqueangle
.
See
Fig
.
18
.
Tightening
Torques
"
Cylinder
head
to
engine
block
(Torx
El2
M10
bolts)
Stage
1
.
.
.....
.
.
.............
30
Nm
(22
ft-Ib)
Stage
2
.
...
...
.
.
...................
..
.
+90°
Stage
3
.....
...
.
..
...................
..
+90°
9
.
Carefully
rotate
crankshaft
in
direction
of
engine
rota-
tion
and
lock
it
at
TDC
by
inserting
BMW
special
tool
no
.
11
2
300
through
transmission
bellhousing
.
See
Fig
.
19
.
CYLINDER
HEAD
REMOVAL
AND
INSTALLATION
113-
7
Fig
.
18
.
Protractor
and
pointer
being
used
to
tighten
bolts
to
specified
torqueangle
(6-cylinder
engine
shown)
.
Fig
.
19
.
BMW
special
tool
11
2
300
inserted
through
bellhousing
hole
and
finto
flywheel
(arrow)
to
lockcrankshaft
at
TDC
.
10
.
Turn
left
chainguide
adjusting
sleeve
in
until
it
just
con-
tacts
the
cylinder
head
(See
Fig
.
14
.)
.
Insert
chain
guide
retaining
screw
and
tighten
.
CAUTION-
11
.
Placechain
sprockets
with
chains
oncamshaftsso
that
Be
sure
timing
chain
does
not
bind
oncrank
gear
when
turning
crankshaft
.
arrowson
sprockets
point
up
and
elongated
holes
in
sprocketsare
centered
to
tapped
holes
in
camshafts
.
See
Fig
.
20
.
CYLINDER
HEAD,
4-CYLINDER