1997 BMW 328i air pump

100-
1
0
ENGINE-GENERAL

Table
d
.
OBD
I
Fault
(Blink)
Codes
(continued)

(1992-1995
modeis
only)

Graphic
representation
of
flashing
Check
Engine
light
fault
code
:
1221
-
;
5
Seconds
.
;--~
2
.5
r
----------------
Check
Engine
light
on

Fault
code
and
meaning



Corrective
action

Check
Engine
light
off

Code
1243
:
Crankshaft
position
sensor
(DME
3
.3
.1
only)



Test
crankshaft
position/rpm
sensor
and
wiring
from
sensor
lo
DME

control
module
.
Repair
Group
120

Code
1244
:
Camshaft
position
sensor
(DME
3
.3
.1
only)



Test
camshaft
position
sensor
and
wiring
fromsensor
to
DME
con-
trol
module
.
Repair
Group
130

Code
1245
:
Electronic
transmission
control
intervention
(DME
3
.3
.1



Check
wiring
between
DME
control
module
and
auto
.
transmission
only)



control
module

Code
1247
:
Ignition
secondary
monitor
(DME
3
.3
.1
only)



Check
secondary
voltage
lo
ignition
coils
.
Check
wiringat
ignition

coils
.
Repair
Group
120

Code
1251
:
Fuel
injector
#1
(DME
3
.113
.3
.1
only)



1
Test
injector
operation/signal
lo
injector
.
Repair
group130

Code
1252
:
Fuel
injector
#2
(DME
3
.113
.3
.1
only)



Test
injector
operation/signal
lo
injector
.
Repair
group130

Code
1253
:
Fuel
injector
#3
(DME
3
.1/3
.3
.1
only)



Test
injector
operation/signal
to
injector
.
Repair
group130

Code
1254
:
Fuel
injector
#4
(DME
3
.1/3
.3
.1
only)



Test
injector
operation/signal
to
injector
.
Repair
group
130

Code
1255
:
Fuel
injector
#5
(DME
3
.1/3
.3
.1
only)



Test
injector
operation/signal
to
injector
.
Repair
group130

Code
1256
:
Fuel
injector
#6
(DME
3
.1/3
.3
.1
only)



Test
injector
operation/signal
lo
injector
.
Repair
group130

Code
1261
:
Fuel
pump
control



Test
fuel
pump
relay
and
fuel
pump
circuit
.
Repairgroup
160

Code
1262
:
Idle
speed
control



Test
idleair
controlvalve
and
signalto
valve
.
Repair
Group
130

Code
1263
:
Fuel
tank
evaporative
(EVAP)
system



Test
EVAP
purge
valve
.
Repair
Group
160

Code
1264
:
Oxygen
sensor
heater



1
Test
oxygen
sensorheater
and
heater
relay
.
Repair
group
130

Code
1265
:
Check
engine
lamp
(DME
3
.3.1
only)



1
Test
for
faulty
bulb
or
wiring
.
Electrical
Wiring
Diagrams

Code
1266
:
VANOS
(DME
3
.3
.1
only)



1
Test
VANOS
solenoid
.
Check
for
signal
to
VANOS
solenoid
.

Code
1267
:
Air
pump
relay
control
(DME
3
.3
.1
only)



Test
air
pump
relay
and
wiring
(where
applicable)
Electrical
Wiring
Diagrams
Code
1271
:
Ignition
coil
#1
(DME
3
.3.1
only)



Test
ignitioncoil
and
wiring
toignitioncoil
.
Repair
Group
120

Code
1272
:
Ignition
coil
#2
(DME
3
.3.1
only)



Test
ignitioncoil
and
wiring
loignitioncoil
.
Repair
Group
120

Code
1273
:
Ignition
coil
#3
(DME
3
.3.1
only)



Test
ignitioncoil
and
wiring
loignitioncoil
.
Repair
Group
120

Code
1274
:
Ignítion
coil
#4
(DME
3
.3.1
only)



Test
ignitioncoil
and
wiring
toignitioncoil
.
Repair
Group
120

Code
1275
:
Ignitioncoil
#5
(DME
3
.3.1
only)



Test
ignition
coil
and
wiring
loignitioncoil
.
Repair
Group
120

Code
1276
:
Ignition
coil
#6
(DME
3
.3.1
only)



Test
ignitioncoil
and
wiring
loignitioncoil
.
Repair
Group
120

Code
1281
:
DME
control
module
memory
supply
(DME
3
.3
.1
only)



Check
voltage
supply
from
battery
lo
DME
control
module
.
Electri-

Code
1282
:
Fault
code
memory
(DME
3
.3.1
only)



Check
DME
control
module
inputs/outputs
.
Control
module
may
be
faulty
.
Repair
Group
130

Code
1283
:
Fuel
injector
output
stage
(DME
3
.3
.1
only)



Check
DME
control
module
inputs/outputs
.
Control
module
may
be
faulty
.
Repair
Group
130

DRIVEABILITY
TROUBLESHOOTING

cal
Wiring
Diagrams

Graphic
representation
of
flashing
Check
Engine
light
fault
code
:
1221

-
;
5
Seconds
.
~-



2
.5;-

Fault
code
and
meaning



Corrective
action

Code
1286
:
Knock
control
test
pulse
(DME
3
.3
.1
only)



Check
DME
control
module
inputs/outputs
.
Control
module
may
be
faulty
Repair
Group
130

Code
1000
(light
remains
off)
:



End
of
fault
code
output-all
fault
codes
have
been
displayed
.
No

~
corrective
action
necessary
.
Repeat
test
if
necessary

Code
1444
:



No
more
faults
.
No
corrective
action
necessary
.
This
code
must
be
present
lo
erase
fault
memory

Basic
Requirements



Preventive
Maintenance

The
following
list
contains
basic
checks
that
should
be
made
when
experiencing
driveability
problems
.

1
.
Check
intake
(induction)
system
for
leaks
.
Check
for

cracked,
loose,
or
disconnected
hoses
and
duct
work
.

Check
that
all
hose
clamps
are
tight
.

NOTE-

An
air
leak
allows
unmeasured
airto
enter
the
engine,
offen
resulting
in
an
in
overly
lean
fuel
mixture
and
causing
driveability
problems
which
will
cause
the
Check
Engine
light
to
come
on
.

Table
d
.
OBD
I
Fault
(Blink)
Codes
(continued)

(1992-1995
models
only)

7
-
1
--------------
Check
Engine
light
on

ENGINE-GENERAL
100-
1
1

Check
Engine
light
off

The
condition
of
the
fuel,
ignition
and
emission
controlsys-

tem
components
has
a
directeffect
onengineperformance

and
driveability
.
BMW
specifies
maintenance
of
certain
parts

at
regular
intervals
lo
keep
the
engine
in
proper
tune
.
Extend-
ing
maintenance
intervals
beyond
the
time
or
mileagerecom-
mended
bythe
manufacturer
can
adversely
affect
the
way
the
engine
runs
.
When
troubleshooting
driveability
problems,
a
good
starting
point
is
to
perform
a
major
engine
service,par-

ticularly
if
one
is
overdue
.
For
maintenance
schedules,
major
engine
service
and
other
driveability-related
maintenance

procedures,
see020
Maintenance
Program
.

Basic
Engine
Settings

2
.
Check
that
the
battery
isin
good
condition
.
Check
that

the
cables
are
tight
and
free
of
corrosion
at
both
ends
.



Idle
speed,
idle
mixture
(%CO),
and
ignition
timing
are
not

Check
that
all
related
ground
points
are
firmly
connect-



adjustable
.
The
adaptive
engine
management
system
is
de-

ed
and
in
good
condition
.
Check
al¡
harness
connectors



signed
lo
automatically
compensate
for
changes
in
engine
op-

for
damage
and
corrosion
.



erating
conditions,
although
the
adaptive
range
is
limited
.

Once
these
limits
are
exceeded,
driveability
problems
usually

3
.
Check
for
prwer
and
ground
at
the
Engine
Control



become
noticeable
.

Module
(ECM)
.
Check
the
main
grounds
for
the
ECM
.

See130
Fuel
Injection
.



NOTE-

If
the
DME
adaptive
limits
are
exceeded,
the
Check
En-
4
.
Check
the
fuses
.
Check
for
sufficient
fuel
in
the
tank
.
If



gine
light
will
come
on,
indicating
an
emission
related
the
engine
ranout
of
fuel,
it
will
take
a
little
time
to
re-



fault
.
See
130
Fuel
Injection,
store
fuel
pressure
.
See
160
Fuel
Tank
and
Fuel

Pump
.
Oxygen
Sensors

5
.
Check
for
spark
at
the
spark
plugs
.
If
the
tachometer

needle
bounces
while
the
engine
is
crankedby
the



A
high
oxygen
level
in
the
engine
exhaust
indicates
a
lean

starter
then
the
ignition
system
is
probably
working
cor-



air-fuel
mixture
and
a
low
oxygen
level
indicates
a
rich
mix

rectly
.
See
120
Ignition
System
.



ture
.
The
oxygen
sensor,
shown
in
Fig
.
10,
measures
the
oxy-

gen
content
in
the
exhaust
gasand
generates
a
variable

6
.
Check
for
any
faults
through
the
On-Board
Diagnostics



voltage
signal
.
Using
that
feedback
signal
asan
input,
the

system
.
See
On-Board
Diagnostics
(OBD)
.



DME
control
module
fine
tunes
the
air-fuel
mixture
.

DRIVEABILITY
TROUBLESHOOTING

If
a
battery
cableconnection
hasno
visible
faults,
but
is
still
suspect,
measure
the
voltage
drop
across
the
connection
.
A
large
drop
indicates
excessive
resistance,
meaning
the
con-
nection
is
corroded,
dirty,
or
damaged
.
Clean
or
repair
the
connection
and
retest
.

NOTE-

For
instructions
on
conducting
a
voltage
drop
test,
and
other
general
electrical
troubleshooting
information,
see600
Electrical
System-General
.

Wiring
and
Harness
Connections

The
electronic
fuel
injection
and
ignition
systems
operate
at

low
voltage
and
current
values,
making
them
sensitive
to

small
increases
in
resistance
.
The
electrical
system
is
routine-

ly
subjected
to
corrosion,
vibration
and
wear,
so
faults
or
cor-

rosion
in
the
wiring
harness
and
connectors
are
common
causes
of
driveability
problems
.

Visually
inspect
all
wiring,
connectors,
switches
and
fuses
in
the
system
.
Loose
or
damaged
connectors
can
cause
inter-

mittent
problems,
especially
the
smallterminals
in
the
ECM

connectors
.
Disconnect
the
wiring
harness
connectors
to

check
for
corrosion
;
and
use
electrical
cleaning
spray
to
re-

move
contaminants
.
Often,
simply
disconnecting
and
recon-

necting
a
dirty
connector
several
times
will
clean
the
terminals
and
help
to
reestablish
good
electrical
contact
.

If
a
wiring
harnessconnectorhasno
visible
faults,
but
is
still

suspect,
measure
the
voltage
drop
across
the
connector
.
A

large
drop
indicates
excessive
resistance,
meaning
the
con-

nector
is
corroded,
dirty
or
damaged
.
Clean
or
repair
the
con-

nector
and
retest
.

Ground
Connections

For
any
electrical
circuit
to
work,
it
must
make
acomplete

path,
beginning
at
the
positive
(+)
battery
terminal
and
ending

at
the
negative
(-)
terminal
.
The
negative
(-)
battery
cable
is

attached
to
the
car's
chassis
.
Therefore,
any
wireor
metal

part
attached
to
the
chassis
provides
a
good
ground
path
back

to
the
negative
(-)
battery
terminal
.

Poorground
connections
are
amajor
source
of
driveabílity

problems
.
If
any
of
themainground
connections
for
the
igni-
tion
system
or
the
fuelinjection
system
are
faulty,
the
in-

creased
resistance
in
that
circuit
will
cause
problems
.

Visually
inspect
al¡
ground
wires
and
connections
for

breaks,
looseness
or
corrosion
.
Be
careful
because
wires

sometimes
break
internally
or
in
areas
not
easily
visible
.
The

main
grounds
for
the
DME
system
are
shown
in
Fig
.
11,Fig
.

12,
and
Fig
.
13
.
Also
check
the
main
fuel
pump
ground
in
the
center
console,
below
the
emergency
brake
handle
.

If
a
ground
connection
has
no
visiblefaults,
but
is
still
suspect,

measure
the
voltage
drop
acrossthe
connection
.
A
large
drop

indicates
high
resistance,
meaning
the
connection
is
corroded,

dirty
or
damaged
.
Clean
or
repair
the
connection
and
retest
.

ENGINE-GENERAL
100-
1
3

UU,~uyi

Fig
.
11
.
Mainground
(arrow)
for
engine
management
system
.
Grounds
are
in
right
rear
of
engine
compartment
.

Fig
.
12
.
Mainground
for
ignition
coils
on
MS
41
.1
engine
manage-
ment
system
(arrow)
.

DRIVEABILITY
TROLIBLESHOOTING

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

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
.

117-2



CAMSHAFT
TIMING
CHAIN

CAMSHAFT
TIMING
CHAIN,

4-CYLINDER

Special
BMW
service
tools
are
needed
for
timing
chain
re-
moval
and
installation
procedures
.
The
special
tools
assure

proper
timing
of
the
valvetrain
.
Precíse
marks
to
setthe
timing

on
the
camshafts
are
not
provided
for
reassembly
.
Read
the

procedures
through
before
beginning
the
job
.

CAUTION-

lf
the
camshaftsare
not
properly
timed,
the
pis-
tons
can
contact
thevalves
.

Camshaft
timing
chain,
removing

(4-cylinder
engines)
U0119-

Fig
.
3
.



Upper
timing
chain
covermounting
bolts(arrows)
.
Thermo-
1
.
Disconnect
negative
(-)cablefrom
battery
.



stat
housing
shown
removed
.
Cylinder
ídentification
sensor
(A)
also
shown
.

CAUTION-

Prior
to
disconnecting
the
battery,
read
the
battery
disconnection
cautions
given
at
the
front
of
this
manual
on
page
viii
.

2
.
Drain
engine
coolant
.
Drain
engine
block
byremoving
block
drain
.
Remove
radiator
cooling
fan
shroud
and
cooling
fan
.
See
170
Radiator
and
Cooling
System
..

WARNING
-

Allow
the
engine
to
cool
before
openingor
draining
the
cooling
system
.

CA
UTION-

On
cars
with
viscous-type
fan
clutch,
fan
has
left
hand
threads
.

NOTE-

The
block
drain
plug
is
located
on
the
exhaust
sideof
the
engine,
below
cylinder
no
.
4
.

3
.
Remove
cylinder
head
cover
.
See
113
Cylinder
HeadRemoval
and
Installation
.

NOTE-

Make
note
of
the
arrangement
of
the
rubber
insulators
when
removing
the
cylinder
head
cover
mounting
belts
.

4
.
Loosen
sparkplugs
.
See
120
Ignition
System
.

5
.
Disconnect
coolant
hoses
from
thermostat
housingon
front
of
cylinder
head
.
Unbolt
thermostat
housing
from
cylinder
head
.

6
.
Remove
cylinder
identification
sensor
from
upper
tim-
ing
chain
cover
.
Remove
upper
timing
chain
cover
.
See
Fig
.
3
.

CAMSHAFT
TIMING
CHAIN,
4-CYLINDER

7
.
Set
engine
to
approximate
TDC
by
rotating
in
normal
operating
direction
until
camshaft
lobes
at
cylinder
no
.

1
are
facing
up
and
toward
each
other
.
See
Fig
.
4
.

0011998
Fig
.
4
.



Engine
set
to
approximate
TDC
.
Cylinder
no
.
1
camshaft
lobes
face
in
and
sprocket
arrows
point
up
(arrows)
.

8
.
Remove
air
conditioning
drive
belt
.
Loosenand
push
aside
air
conditioning
compressor
.
Remove
air
condi-
tioning
compressor
mounting
bracket
.
See
640
Heat-
ing
and
Air
Conditioning
.

9
.
Remove
engine
drive
belts
and
coolant
pump
pulley
.
See
020
Maintenance
Program
.

10
.
Secure
crankshaft
vibration
damper
to
prevent
crank-
shaft
from
turning
.
Using
a
socket,
loosen
vibration
damper
hub
center
bolt
.

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
.