1992 BMW 318i 100

100-
1
4
ENGINE-GENERAL

0013131

Fig
.
13
.
Main
chassis
ground
(arrow)
inleft
front
of
engine
compart-
ment
.

Fuel
Supply

For
the
engine
tostart
and
run
properly,
the
injection
sys-

tem
must
deliver
fuel
in
precise
proportion
to
the
amount
of
air

entering
the
engine
.
Todo
this,
the
injection
system
requires

an
unrestricted
supply
of
fuel
from
the
fuel
pump
.

If
the
fuel
pump
is
not
working,
the
engine
will
notrun
.
If
the
fuel
filter
or
a
fuel
line
is
restricted,
the
engine
may
run
poorly
.
If
the
restriction
is
severe
enough
the
engine
will
not
start
.
lf

fuel
delivery
problemsare
suspected,
perform
the
tests
de-

scribed
in
160
Fuel
Tank
and
Fuel
Pump
.

The
fuel
pressure
created
by
the
fuel
pump
is
controlled
by
a
pressure
regulator
thatreturns
excess
fuelto
the
tank
.
Any
change
in
fuel
pressure
will
cause
a
change
in
the
base
air-fuel

mixture
delivered
to
the
engine
.
If
the
fuel
pressure
is
too
low,
the

base
air-fuel
mixture
will
be
lean
.
lf
the
fuel
pressure
is
too
high,
the
base
mixture
will
be
rich
.
Fuel
pressure
tests
aredescribed
in
160
Fuel
Tank
and
Fuel
Pump
and130
Fuel
Injection
.

NOTE-

Fuel
pressure
tests
require
a
pressure
gauge
.
If
thistoolís
not
avaílable,
the
tests
can
be
performed
byan
authorized
BMW
dealer
or
other
qualified
shop
.

DRIVEABILITY
TROUBLESHOOTING

Properly
operating
fuel
injectors
play
amajor
role
in
fuel
de-

livery
.
The
DMEECM
switches
the
injectors
on
and
off
at
the

negative
(-)
or
ground
side
of
the
connectors
.
Posítíve
(+)
bat-

tery
voltage
is
always
present
at
the
connectors
when
theen-

gine
is
running
.
An
injector
that
fails
or
loses
power
will
not

open,
creating
a
lean
air-fuel
mixture
and
causing
the
engine
to

run
poorly
when
coldor
stumble
on
acceleration
.
An
injector

that
shorts
to
ground
will
remain
open
constantly
when
the
en-

gine
is
running,
creating
a
richair-fuel
mixture
that
can
dilute

engine
oil,
foul
the
spark
plugs,
cause
a
rough
idle,
and
damage

the
catalytic
converter
.

Table
e
lists
additional
symptoms
of
common
engine
drive-

ability
problems,
their
probable
causes,
and
the
suggested

corrective
actions
.
The
entries
in
boldtype
in
the
corrective

action
column
indicate
the
repair
groups
where
applicable
test

and
repair
procedures
can
befound
.

NOTE-

Most
of
the
symptoms
fisted
in
Table
e
will
also
cause
the
Check
Engine
light
to
come
on
.
If
the
light
is
on,

check
for
any
stored
faults
as
the
first
step
ín
trouble-
shooting
driveability
complaints
.

al
Icld

Table
e
.
Engine
Driveability
Troubleshooting

c
l



1



I



f



I



I
Oxygen
sensor
faulty



Test
oxygen
sensor
.

ENGINE-GENERAL
100-
1
5

SYMPTOMS

a
.
Engine
fafs
tostart

b
.
Engine
startsbut
stops
immediately

c
.
Erratic
engine
idle

d
.
Poor
engine
responseon
acceleration

e
.
Erratic
engine
operation
in
al¡
speed
ranges

f
.
Excessive
fuel
consumption
g
.
Poor
enginepower,
fails
to
rev
up
h
.
CO
content
toolow

i.
CO
content
too
high

CAUSES



CORRECTIVE
ACTION

a



Fuel
pump
faulty



Test
fuel
pump
.
Repair
Group
160

a



e



Ignition
system
faulty



Test
ignition
system
.
Repair
Group
120
a



Main
relay
or
fuel
pump
relay
faulty



Test
main
relay
.
Repair
Group
130
a



Crankshaft/rpm
position
sensor
faulty



Test
crankshaft/rpm
sensor
.
120
b



c



h



i



ldle
speed
control
valve
faulty



Test
idle
speed
control
valve
.

c



d



e



Throttle
position
sensor
faulty
or
idle
signal
to



Test
throttle
position
sensor
.
DME
control
module
missing
.

c



d



h



i



Mass
air
flow
sensor
faulty



Test
mass
air
flow
sensor
Repair
Group
130
a



b



c



d



e



h



Large
air
intake
system
leak



Check
for
major
intake
air
leaks
downstream
of
mass
air
flow
sensor
.

a



c



d



e



g



h



Fuel
pressure
too
low



Test
fuel
pressure
.
Repair
Group
130

?



I



F
ue
l
pr
essu
r
e
t
oo
high



T
est
f
u
el
pressure
.
Repair
Group
130
d



e



g



h



Fuel
pump
delivery
volume
too
low



Test
fuel
pump
delivery
volume
.
Repair
Group
160
a



c



e



f



h
q
C
oo
l
a
nt
t
e
mp
e
r
a
t
u
r
e
se
n
so
r
f
au
lty



--]
T
est
coo
l
a
n
t
temp
erature
sensor
.

c



e



~



f



i



~
Fuel
injectors
leaking



Check
fuel
injectors
and
replace
leaking
injectors
.

~
Repair
Group
130

Throttle
plate
binding
or
incorrectly
adjusted



Check
throttle
plate
and
adjust
if
necessary
.

a



c



Electrical
connections
loose,
broken,
or
cor-



Visually
inspect
connectors
and
correct
any
roded



faults
.
Repair
Group
600
Ground
connections
loose,
broken,
or
corroded



Visually
inspect
ground
connections
and
correct
any
faults
.
Repair
Group
600

c



e
~



f



CO
content
too
high



Test
air
flowor
mass
air
flow
sensor
.
Repair

~
Group
130
a



b



c



d



e



CO
content
too
low



Test
mass
air
flow
sensor
.
gb



c



d



e



f



g



h



i



Inputsignals
to
ECM
missing,
ECM
in
limp



Make
electrical
tests
at
DMEECM
relay
.
Repair

home
mode



Group
130
a
~
b
~
c
~
d



e]



f



g



h



i



ECM
faulty



Test
DMEECM
inputs
.
If
all
inputs
are
correct,
replace
ECM
.

DRIVEABILITY
TROUBLESHOOTING

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

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

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

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

117-
1
4



CAMSHAFT
TIMING
CHAIN

22
.
Installation
of
remaining
parts
is
reverse
of
removal,



When
theengine
is
running,
the
piston
housing
is
supplied

noting
the
following
:



with
pressurized
engine
oil
.
At
idie,
the
solenoid
isin
the
off

"
When
installing
thermostat,
make
sure
arrow
or
vent



position
(de-energized)
and
valve
timing
is
maintained
in
the

hole
faces
up,
if
applicable
.



normal
position
:
When
the
solenoid
is
energized,
the
gear
cup

"
Refill
cooling
systemas
described
in
170
Radiator



piston
moves
forward
to
advance
the
camshaftby
a
maximum

and
Coming
System
.



of
12
.5
.

"
Install
oil
pan
as
described
in
119
Lubrication
Sys-

tem
.
"
Fill
engine
with
oil
and
install
a
new
oil
filter
as
de-

scribed
in
020
Maintenance
Program
.

"
Insta¡¡
ground
wires
at
cylinder
head
cover
mounting

studs
and
at
front
of
cylinder
head
and
thermostat

housing,
where
applicable
.



VANOS
system
operation,
testing

Tightening
Torques



There
are3
special
tools
required
to
check
VANOS
opera-

"
Coolant
drain
plugto
cylinder
block
.
.
25
Nm
(18
ft-Ib)



tion
;
an
electricaltest
lead
(BMW
special
tool
no
.
12
6
410),
an

"
Radiator
cooling
fan
to
coolant
pump
.
40
Nm
(30
ft-Ib)



air
line
fitting
(BMW
special
tool
no
.
11
3
450),
and
a
crank-

"
Radiator
drain
screw
to
radiator
...
.
2
.5
Nm
(22
in-Ib)



shaft
TDC
locking
tool
(BMW
special
tool
no
.
112
300)
.

"
Upper
timing
chaincover
to
cylinder
head



The
test
leal
is
used
to
power
the
solenoid,
simulating
the
M6
nut
...
.....
.............
..
.
10
Nm
(89
in-lb)



ground
signal
from
the
DME
control
unit
.
The
air
line
fitting
M8
bolt
.....
....
.
.
.............
22
Nm
(17
ft-Ib)



takes
the
place
of
the
oil
supply
line
fitting
to
simulate
oil
Ares-
"
VANOS
control
unit
to
cylinder
head



sure
.
The
locking
tool
positions
and
locks
the
crankshaft
at

M6
nut
.........
..
..
.
..........
10
Nm
(89
in-lb)



TDC,
cylinder
no
.
l.
M8
bolt
........
...
.............
22
Nm
(17
ft-Ib)

"
VANOS
oil
supply
pipe
to
VANOS
control
unit



1
.
Remove
alternator
cooling
air
duct
.

banjo
bolt
.......
..
..
.
..........
32
Nm
(24
ft-Ib)

VANOS
(VARIABLE
VALVE
TIMING)



3
.
Remove
top
plastic
enginecovers
.
Disconnect
ignition

coil
harness
connectors
fromcofs
.
Remove
ignition

1993
and
later
6-cylinder
engines
are
equipped
with
a
vari-



coils
.

able
valve
timing
system
called
VANOS
.
This
system
is
con-

trolled
by
the
engine
management
system
and
dynamically



4
.
Remove
cylinder
head
cover
mounting
bolts
and
re-

adjusts
intake
camshaft
timing
based
on
engine
load,
engine



move
cylinder
head
cover
.
Unclip
andremove
oil
baffle

speed
and
engine
temperature
.



cover
from
above
intake
camshaft
.
See
113
Cylinder

Head
Removal
and
installation
.

The
main
components
of
the
VANOS
system
are
the
control

unit
with
piston
housing
and
integral
spool
valve,
and
the
mod-

ified
intake
camshaft
.
See
Fig
.
35
.

VANOS
(VARIABLE
VA
LVE
TIMING)

Fig
.
35
.
VANOS
control
unit
with
modified
intake
camshaft
.

B11001

WARNING
-

Special
BMW
service
tools
are
required
to
check
and
repair
the
VANOS
System
.
Read
theproce-

dures
through
before
beginning
the
job
.

2
.
Disconnect
crankcase
ventilation
hose
fitting
from
cyl-

inder
head
cover
.

NOTE-

Note
the
arrangement
of
the
cylinder
head
cover
bolt
insulators
and
gaskets
during
removal
.

5
.
Set
engine
to
approximate
TDC
by
rotating
in
normal

operating
direction
until
camshaft
lobes
at
cylinder
no
.

1
are
facing
each
other
.
See
Fig
.
20
.

6
.
Set
engine
to
TDC
by
aligning
"0/T"
mark
(0°TDC)on

front
vibration
damper
withcast
boss
on
lower
timing
chain
cover
.
See
Fig
.
21
.

7
.
Lock
crankshaft
in
position
by
inserting
BMW
special

tool
no
.
11
2
300
through
transmission
bellhousing
and

into
hole
in
flywheelor
driveplate
.
See
Fig
.
36
.

NOTE-

Confirm
that
the
locking
tool
has
been
correctly
in-
stalled
by
trying
to
rotatethe
crankshaft
.

IGNITION
SYSTEM
DIAGNOSTICS



IGNITION
SYSTEM
SERVICE

Poor
driveability
may
have
a
variety
of
causes
.
The
fault



On
4-cylinder
engines,
an
ignition
coil
pack
is
mounted
to

may
lie
with
the
ignition
system,
the
fuel
system,
parts
of
the



the
passenger
side
strut
tower
in
the
engine
compartment
.

emission
control
system,
or
a
combination
of
the
three
.
Be-



The
coil
pack
integrates
4
individual
coils
.

cause
of
these
interrelated
functions
and
their
effects
oneach

other,
it
is
often
difficult
to
know
where
to
begin
looking
for



On
6-cylinder
engines,
an
ignition
coil
is
located
directly

problems
.



above
each
spark
plug
.

For
this
reason,
effective
troubleshooting
should
alwaysbe-

gin
with
an
interrogation
of
the
On-Board
Diagnostic
(OBD)

system
.
The
OBD
system
detects
certain
emissions-related

engine
management
malfunctions
.
When
faults
are
detected,

the
OBD
system
stores
a
Diagnostic
Trouble
Code
(DTC)
in

the
system
ECM
.
In
addition,
the
Check
Enginewarning
light

will
come
on
if
an
emissions-related
fault
is
detected
.

Two
generations
of
OBD
areusedon
the
cars
coveredby

this
manual
.
See
100
Engine-General
for
OBD
information
.

On-Board
Diagnostics

"
1992-1995
models
............
...
.
..
...



OBD
I

"
1996
and
later
models
.........
.......
..
OBD
II

NOTE-

"
On
carswith
OBD
ti,
specialized
OBD
11
scan
tool

equipment
mustbeused
to
access
DTCs,
either
using

the
BMW
special
tool
or
a
`generic"
OBD
11
scan
tool
.

"
The
OBD
11
fault
memory
(including
an
illuminated

Check
Engine
light)
can
only
be
reset
using
the
spe-

cial
scan
tool
.
Removing
the
connector
from
the
ECM

or
dísconnecting
the
battery
will
not
erase
the
fault

memory
.

Basic
Troubleshooting
Principies

An
engine
that
starts
and
runs
indicates
the
ignition
system

is
fundamentally
working-delivering
voltage
toat
least
some

of
the
sparkplugs
.
A
hard-starting
or
poor-running
engine,

however,
may
indicate
ignition
coil
problems,
cracked
or
dete-

riorated
spark
plug
wires
(4-cylinder
engines
only),
and
worn

or
fouled
spark
plugs
.

WARNING
-

Inefficient
combustion
(richair/fuel
mixture)
can

cause
the
catalytic
converter
to
overheat
and
plug
.

An
overheated
catalytic
converter
can
also
bea
tire

hazard
.

Checking
for
Spark

IGNITION
SYSTEM



120-
3

WARNING
-

If
a
spark
test
is
done
incorrectly,
damage
to
theen-
gine
control
module
(ECM)
or
the
ignitioncoil(s)
may
result
.

Checking
for
spark
is
difficult
onengines
with
distributorless

ignition
systems
.

Try
Rmovng
the
plugs
and
inspecting
for
differences
be-

tween
them
.
A
poor-firing
plug
may
be
wet
with
fuel
and/or

black
and
sooty,
butnot
always
.
If
a
coil
is
not
operating,
the

engine
management
system
will
electrically
disable
the
fuel
injectorto
that
cylinder
.
The
key
is
to
look
for
differences
be-

tween
cylinders
.

Ignition
coil,
testing
and
replacing

(4-cylinder
engine)

1.
Disconnect
mainharness
connector
from
coils
:

"
On
M42
engine,
remove
plastic
covering
from
coils
and

disconnect
individual
harness
connectors
.

"
On
M44
engine,
disconnect
main
harness
connectorat

end
of
coil
pack
.
See
Fig
.
3
.

Fig
.
3
.



Ignition
coil
pack
for
M44
engine
(arrow)
.
Coil
harness
con-

nector
shown
at1
.

IGNITION
SYSTEM
SERVICE