1996 BMW 323i 130

General
Data
and



010
FundamentalsfortheDo-lt-YourselfOwner

Maintenance



020
Maintenance
Program

Engine

Transmission

Suspension,

Steering
and

Brakes

4
Body

100
Engine-General

110



Engine
Removal
and
Installation
113



Cylinder
Head
Removal
and
Installation
116



Cylinder
Head
and
Valvetrain
117



Camshaft
Timing
Chain

119



Lubrication
System

200
Transmission-General
210
Clutch
230
Manual
Transmission

510



Exterior
Trim,
Bumpers



520



Seats

Bo
y
Equipment



512
DoorWTdws



540



nr
t

513



InteriorTrim



541



Convertible
Top

515



Central
Locking
and
Anti-Theft

600



Electrical
System-General



620



Instruments

Electrical
S



stem
610
Electrical
Component
Locations



630
Exterior
Lighting

611



Wipers
and
Washers



640



Heating
and
Air
Conditioning

6



612



Switches
and
Electrical
Accessories



650



Radio

Equipment
and



720
SeatBelts

Accessories



721
Airbag
System
(SRS)

Electrical
Wiring

Diagrams

Foreword
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v

Warnings
and
Cautions
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..
back
of
book

300



Suspension,
Steering
and



330



RearSuspension

Brakes-General



331



Final
Drive

310



Front
Suspension



340



Brakes

320



Steering
and
Wheel
Alignment

400
Body-General



411
Doors

410



Fenders,
Engine
Hood



412



Trunk
Lid

120



Ignition
System
121



Battery,Starter,
Alternator
130



Fue¡
Injection
160



Fuel
Tank
and
Fuel
Pump
170



Radiator
and
Cooling
System180



Exhaust
System

240



Automatic
Transmission
250



Gearshift
Linkage

260
Driveshaft

FUNDAMENTALS
FOR
THEDO-ITYOURSELF
OWNER



010-
5

WARNING
-

Avoid
getting
tools
or
clothing
near
the
battery
.
Bat-tery
electrolyte
is
a
corrosive
acid
.
Be
careful
with

brake
fluid,
as
it
can
damage
the
cars
paint
Finally,
keep
rubber
parts
such
as
hoses
and
bolts
free
from
oil
orgasoline,
as
they
will
cause
the
material
to
soften
and
fail
prematurely
.

Non-reusable
Fasteners

Many
fasteners
usedon
the
cars
coveredby
this
manual

mustbe
replaced
with
new
osesonce
they
are
removed
.
These



Fig
.
4
.
General
sequence
for
alternately
tightening
multiple
fasten-

include
butarenot
limited
to
:
bolts,
nuts
(self-locking,
nylock,



ers
.

etc
.),
cotterpins,
studs,
brake
fittings,
rol¡
pins,clips
and
wash-

ers
.
Genuine
BMW
parts
should
be
the
only
replacement
parts



NOTE-

used
for
this
purpose
.



"
Metric
bolt
classes
or
grades
are
markedon
the
bolt'

head
.

Some
bolts
are
designed
to
stretch
during
assembly
and
are

permanently
altered
rendering
them
unreliable
once
removed
.

These
are
known
as
torque-to-yield
fasteners
.
Always
replace
fasteners
where
instructed
to
doso
.
Failure
to
replace
these

fasteners
could
cause
vehicle
damage
and
personal
injury
.

See
an
authorized
BMW
dealer
for
applications
and
ordering

information
.

Tightening
Fasteners

When
tighteningthe
bolts
ornuts
that
attach
acomponent,
it

is
always
good
practice
to
tighten
the
bolts
gradually
and
evenly

to
avoid
misalignment
or
over
stressing
anyone
portion
of
the

component
.
For
components
sealed
with
gaskets,
this
method

helps
to
ensure
that
thegasket
will
seal
properly
and
complete-

ly
.

Where
there
are
severa¡
fasteners,
tighten
them
in
a
se-

quence
alternating
between
opposite
sides
of
the
component
.

Fig
.
4
shows
such
a
sequence
for
tightening
six
bolts
attaching

a
typical
component
.
Repeat
the
sequence
until
al¡
the
bolts
are
evenly
tightened
to
theproper
specification
.

"
Do
not
confuse
wrench
sizewithbolt
diameter
size
.
Fora
listing
of
the
common
wrenches
used
on
vari-
ous
bolt
diameters,
see
Basic
Tool
Requirements
.

Table
a
.
General
Bolt
Tightening
Torques
in
Nm

(max
.
permissible)

Bolt
Class
(according
to
DIN
267)
Bolt
diameter
5
.6
5
.8
6
.8
8
.8
10
.9
12
.9

M5
2
.5
3
.5
4
.5
6810

M6



4
.5



6



7
.5



10



14
`
17

M8



11



15
-



18



24



34



40

M10
233036476679

M12
3952
62
82115140

M14
6282
98
130
180220

M16
9426150
200280340

M18
130174210280
390
470

For
some
repairs
a
specific
tightening
sequence
is
neces-

sary,
or
a
particular
order
of
assembly
is
required
.
Such
special



Gaskets
and
Seals

conditions
are
noted
in
the
text,
and
the
necessary
sequence
is

described
or
illustrated
.
Where
no
specific
torque
is
listed,
Ta-



The
smoothest
metal
mating
surfaces
still
have
imperfec

blea
can
be
used
as
a
general
guide
for
tightening
fasteners
.



tions
that
can
allow
leakage
.
To
prevent
leakage
atcritica¡

joints,
gaskets
of
soft,
form-fitting
material
are
used
to
fill
in
the

WARNING
-



imperfections
.
Table
ais
a
general
reference
only
.
The
values
list-

ed
in
the
table
are
not
intended
to
be
used
asa
sub-



To
be
most
effective,
gaskets
are
designed
to
crush
and
be-
stitutefor
torques
specifically
called
out
in
the
text



come
thinner
as
the
mating
parts
are
bolted
together
.
Once
a
throughout
this
manual
.



gasket
has
been
used,
it
is
no
longer
capable
of
makingas

good
a
sea¡
as
when
new,
and
is
muchmore
likely
toleak
.
For

this
reason,
gaskets
should
not
be
reused
.
Always
plan
to
use

new
gaskets
for
any
reassembly
.
Some
gaskets-such
as
head
gaskets-are
directional
.
Make
sure
that
these
are
in-

stalled
correctly
.
This
same
logic
applies
to
any
part
used
for

sealing,
including
rubber
O-rings
and
copper
sealing
washers
.

ADVICE
FOR
THE
BEGINNER

020-
1
2



MAINTENANCE
PROGRAM

6-cylinder
engines
use
a
coil-on-plug
configuration,
and
re-



Battery
cablesshould
be
tight
.
The
terminals,
the
cable
moval
of
thetop
engine
cover
(between
the
camshafts)
and
ig-



clamps,
and
the
battery
case
should
be
freeof
the
white
deposits
nition
cofs
are
necessary
.
See
Fig
.
12
.
Blow
away
any
dust
or



that
indicate
corrosion
and
acid
salts
.
Even
a
thin
¡ayer
of
dust
dirt
around
the
ignition
coils,
and
then
remove
the
coils
.
Blow



containing
conductive
acid
salts
can
cause
battery
discharge
.
away
any
dustor
dirt
around
the
sparkplugs
.
Remove
the
spark

plugs
.



To
remove
battery
corrosion,
begin
by
disconnecting
theca-

bles
.
Disconnect
the
negative
(-)
cable
first
.
Clean
the
terminal

posts
and
the
cable
clamps
with
a
wire
brush
.
Clean
the
main
chassis
ground
terminal
next
to
the
battery
.
Corrosion
can
be
washedaway
with
a
baking
soda
and
water
solution
that
will
neutralize
the
acid
.
Apply
the
solution
carefully,
though,since
ít
will
also
neutralize
the
acid
inside
the
battery
.
Reconnect
the
ca-
ble
clamps,
positive
(+)
cable
first
.
Lightly
coat
the
outside
of
the

terminals,
hold
down
screws,
and
clamps
with
petroleum
jelly,
grease,
or
a
commercial
battery
terminal
corrosion
inhibitor
.

Fig
.
12
.
Ignition
coil
being
removed
from
spark
plug
on
M52
engine
.

NOTE-

If
necessary,
see
120
Ignition
System
for
more
details
on
coil
removal
.

B11004

Lightlylubricate
the
new
spark
plug
threads
with
a
small
amount
of
anti-seize
compound
.
Thread
the
plugs
into
the
cyl-
inder
head
byhand
to
prevent
cross-threading
.

Tightening
Torque

"
Spark
plug
to
cylinder
head
.......
25
Nm
(18
ft-ib)

Idie
Speed

Engine
¡dle
speed
canchange
due
to
a
number
of
factors,
in-
cluding
normal
wear
.
The
idle
speed
is
electronically
adaptive
and
non-adjustable
.
See
130
Fuel
Injection
for
more
information
.

Battery,
checking
and
cleaning

The
battery
is
located
in
the
right
side
of
the
luggage
com-
partment
.
Simple
maintenance
of
the
battery
and
its
terminal
connections
will
ensure
maximum
starting
performance,
espe-
cially
in
winter
when
colder
temperaturesreduce
battery
power
.

ENGINE
COMPARTMENT
MAINTENANCE

WARNING
-

"
Prior
to
disconnecting
the
battery,
read
the
bat-
tery
disconnection
cautions
given
at
the
front
of
this
manualonpage
viii
.

"
Battery
acid
is
extremely
dangerous
.
Take
care
to
keep
it
from
contacting
eyes,
skin,
or
clothing
.
Wear
eye
protection
.
Extinguish
all
smoking
ma-
terials
and
do
not
worknear
any
oyen
flames
.

Battery
electrolyte
should
be
maintained
at
the
correct
level
just
above
the
battery
plates
and
their
separators
.
The
correct
leve¡
is
approximately
5
mm
(
1
/4
in
.)
above
thetop
of
battery
plates
orto
thetop
of
the
indicator
marks
(if
applicable)
.
The
battery
plates
and
the
indicator
marks
can
beseen
once
the
fill-
er
caps
are
removed
.
If
the
electrolyte
level
is
low,
replenish
it
by
adding
distilled
water
only
.

Battery,
repiacing

Batteries
are
rated
by
ampere
hours
(Ah),
the
number
of
hoursa
specific
current
draín
can
be
sustained
before
complete
discharge,
or
by
cold
cranking
amps
(CCA),
the
number
of
amps
available
to
crank
the
engine
in
cold
weather
conditions
.
In
general,
replacement
batteries
should
alwaysbe
rated
equal
or
higherthan
the
original
battery
.

CAUTION-

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

The
battery
is
held
in
place
bya
single
hand
screw
and
píate
.
A
secure
battery
hold-down
is
important
in
order
to
prevent
vi-
brations
and
road
shock
from
damaging
the
battery
.

NOTE-
NOTE-
"
Always
disconnect
the
negative
()
cable
first,
and
Design
characteristics
of
the
convertible
body
cause
vi-



connect
ft
last
While
changing
batteries,
clean
away
brations
in
the
trunk
area
.
Therefore,
E36
convertibles



any
corrosion
in
or
around
the
battery
tray
.
require
a
specialbattery
designed
for
constant
vibra-
tion
.
When
repiacing
the
battery,
be
sure
the
replace-



"
Design
characteristics
of
the
convertible
body
cause
ment
is
designed
specffically
for
the
convertible
.



vibrations
to
oscillate
in
the
trunk
area
.
Therefore,
the
convertible
model
uses
a
specialbattery
designed
for
this
constant
vibration
.

020-
1
4



MAINTENANCE
PROGRAM

uu11989

Fig
.
14
.
Engine
drive
belt
tensíoner
being
released
on
late
4-cylinder
engine
.
Pry
off
tensioner
cover
and
then
lever
tensioner
in
clockwise
direction
(as
facing
engine)
and
slip
beltoff
pulleys
.



Fig
.
17
.
Engine
drive
belt
routing
for
late
4-cylinder
engine
with
poly-
ribbed
drivebelts
.

CA
UTION-

Use
only
BMW
approved
phosphate-free
anti-
freeze
when
filling
the
cooling
system
.
Use
of
anti-

B11177



freeze
containing
phosphates
!s
considerad
to
be

Fig
.
15
.
Engine
drive
belt
tensioner
being
released
on
6-cylinder
en-



harmful
to
the
cooling
system
.

gine
.
Pry
off
tensioner
cover
and
then
lever
tensioner
in
clock-
wise
direction
(as
facing
engine)
and
slipbelt
off
pulleys
.



A
translucent
expansion
tank,
or
overflow
resenroir,
providesmonitóring
of
coolant
leve¡
.
Because
the
expansion
tank
is
translucent,
thecoolant
level
can
be
checked
visually
without
opening
the
system
.
Always
check
thecoolant
leve¡
with
theen-gine
cold
.
The
coolant
leve¡
should
be
at
the
maximum
mark
on
O



o
'~
I



the
expansion
tank,
as
shown
in
Fig
.
18
.

OO



Hose
connectionhld
b
tiht
s
soueg



an
ddry
.
Coolánt
seepage
indicates
either
that
the
hose
clamp
is
loose,
that
the
pose
is

ENGINE
COMPARTMENT
MAINTENANCE

0012470

Fig
.
16
.
Engine
drive
belt
routing
for
6-cylinder
engine
.
A/C
compres-
sor
drive
belt
not
shown
.

'92

irá
Alternator
belt

Coolant~
0
pp



o0o



Belt
tensioner

Cooling
System
Service

0013000

Cooling
system
maintenance
consists
of
maíntaining
thecoolant
leve¡,
inspecting
hoses
.
Because
the
coolant's
anti-cor-

rosion
and
anti-freeze
additives
gradually
lose
their
effective-
ness,
replacement
of
thecoolant
every
two
years
up
to
1996
models,
and
every
three
years
from
1996
is
recommended
.
Asa
preventive
measure,
replacement
of
the
cooling
system
hos-
es
every
four
years
is
also
recommended
.

damaged,
or
that
the
connection
is
dirty
or
corroded
.
Dried
cool-
ant
has
a
chalky
appearance
.
Hoses
should
be
firm
and
springy
.
Replace
any
hose
that
is
cracked,
that
has
become
soft
and
limp,
or
has
been
contaminated
by
oil
.
See
Fig
.
19
.

Power
steering
fluid,
checking
leve¡

Check
the
power
steering
fluid
level
in
the
fluid
reservoir
.
Park
thecar
on
leve¡
ground
with
the
engine
off
.
The
level
is
cor-
rect
if
it
is
between
the
MIN
and
MAX
marks
on
the
dipstick
.
See
Fig
.
20
.
If
the
leve¡
is
below
the
MIN
mark,
start
the
engine
andadd
fluid
to
the
reservoir
to
bríng
the
leve¡
up
.
Stop
the
engine
and
recheck
the
leve¡
.
Hand-tighten
the
reservoir
cap
.

NOTE-

Use
a14
mm
or17
mm
alíen
bit
socket
to
remove
the
drain
plug
.

"
If
thecar
is
raised
in
the
air,
it
shouldbe
leve¡
.

Fuel
tank
and
fuel
fines,
inspecting

0012474

Inspect
the
fuel
tank,
fuel
lines,
and
fuel
system
for
damage

or
leaks
.
Check
for
fuel
leaks
in
the
engine
compartment
or

fuel
odors
in
the
passenger
compartment
.
Check
for
faultyfuel

lines
bybending
them
.
If
any
leaks
are
present,
fuel
should
be

expelled
.
Check
for
any
evaporative
emissions
hoses
that

may
have
become
disconnected,
checking
carefully
at
the

charcoal
canister
and
evaporative
emissionspurge
system
.

See130
Fuel
Injection
and
160
Fuel
Tank
and
Fuel
Pump

for
component
locations
and
additional
information
.

WARNING
-

When
checking
for
fuel
leaks,
the
engine
must
be
cold
.
A
hot
exhaust
manifold
or
exhaust
system
could
cause
the
fuel
to
ignite
or
explode
causing
se-
rious
personal
injury
.
Uentilate
the
workarea
and
clean
up
spilled
fuel
immediately
.

Clutch
fluid,
checking

The
hydraulic
clutch
and
the
brake
system
share
the
same

reservoir
and
the
same
brake
fluid
.
Clutch
fluid
leve¡
and
brake

fluid
level
are
checked
at
the
same
time
.
See340
Brakes
for

more
information
.
See210
Clutch
for
information
on
the
clutch

and
the
hydraulic
clutch
operating
system
.

MAINTENANCE
PROGRAM



020-19

Drive
axie
joint
boots,
inspecting

100
Engine-General

The
protective
boots
must
be
closely
inspected
for
cracks
andany
other
damage
that
will
allow
contaminants
to
get
ínto
the
joint
.
If
the
rubber
boots
faf
,
the
water
and
dirt
that
enter
the
joint
will
quickly
damage
¡t
.
Replacement
of
the
drive
axle
joint
boots
and
inspection
of
the
joints
are
described
in
330
Rear
Suspension
.

BODY
AND
INTERIOR
MAINTENANCE

Windshield
Wiper
Biade
Maintenance

Common
problems
with
the
windshield
wipers
include

streaking
or
sheeting,
water
drops
after
wiping,
and
blade
chat-

ter
.
Streaking
is
usually
caused
when
wiper
blades
are
coated

with
road
film
or
car
wash
wax
.
Clean
the
blades
using
soapy
water
.
If
cleaning
theblades
does
not
cure
the
problem
then

they
should
be
replaced
.
BMW
recommends
replacing
the
wip-
er
blades
twice
a
year,
before
and
after
the
cold
season
.
Onold-

er
cars,
check
the
tension
spring
that
holds
the
wiper
to
the

glass
.
Replace
the
wiper
arm
if
the
springs
are
weak
.

Drops
that
remainbehind
after
wipingare
caused
by
oil,
road

film,
or
diesel
exhaust
coating
the
windshield
.
Use
an
alcohol
or

ammonia
solution,
or
a
non-abrasive
cleanser
to
clean
the

windshield
.

Wiper
blade
chatter
may
be
caused
by
dirty
or
worn
blades,

bya
dirty
windshield,
or
by
bentor
twisted
wiper
arms
.
Clean

the
blades
and
windshield
as
described
above
.
Adjust
the
wiper

arm
so
that
there
is
even
pressure
along
the
blade,
and
so
that

the
blade
is
perpendicular
to
the
windshield
atrest
.
Lubricate

the
wiper
linkage
with
a
light
oil
.
The
linkage
is
located
under

the
hood
on
the
drivers
side
.
If
the
problem
persists,
theblades
are
excessively
aged
or
worn
and
should
be
replaced
.
See
611
Wipers
and
Washers
.

Body
and
hinges,
lubricating

The
door
locks
and
lock
cylinders
canbe
lubricated
with
an

oil
that
contains
graphite
.

The
body
and
door
hinges,
the
hood
latch,
and
the
door

check
rods
should
be
lubricated
with
SAE
30
or
SAE
40
engine

oil
.
Lubricate
the
seat
runners
with
multipurpose
grease
.
Do
not

apply
any
oil
to
rubber
parts
.
If
door
weatherstrips
are
sticking,

lubricate
them
with
silicone
spray
or
talcum
powder
.
The
hood

release
cable
should
be
lubricated
as
well
.

The
use
of
winter
lock
de-icer
spraysshould
be
kept
to
an
ab-

solute
minimum,
as
the
alcohol
in
the
de-icer
will
wash
the

grease
out
of
the
lock
assemblies,
and
may
cause
the
locks
to

corrode
internally,
or
become
difficult
to
operate
.

ENGINE-GENERAL
100-1

camshaft
secondary
drive,
causing
thecamshaft
to
"advance"

12
.5°
.
The
helical
gears
are
cut
so
that
forward
motion
of
the

gear
cup
is
transiated
into
rotational
motion
of
the
camshaft
.

See
117
Camshaft
Timing
Chain
for
testing
and
repair
infor-
mation
on
the
VANOS
system
.

DISA
(Dual
Resonance
Intake
System)

DISA,usedon
4-cylinder
engines,
is
a
dual
intake
runner

system
that
effectively
provides
the
advantages
of
both
short

and
long
intake
runners
within
the
same
engine
.
For
best
per-

formance,
long
intake
runners
aremost
beneficial
atlow-
and
mid-engine
speeds
(below
4,200
rpm),
and
short
intake
run-
ners
enhance
torque
at
high
engine
speeds
(above4,200
rpm)
.

NOTE-

The
term
DISA
comes
from
the
German
words
Differ-
enzierte
Sauganlage,
and
can
roughty
be
transiated
as
a
differing
intake
manifold
configuration
.

The
DISA
solenoid
valve
is
controlled
by
the
DME
control

module,
using
engine
speed
as
the
primary
input
.
The
main

components
of
the
system
are
the
modified
twin-section
in-

takemanifoldwith
change-over
valve,
the
twin-barrel
throttle

body,
and
the
electrical/pneumatic
actuating
components
.

See
Fig
.
4
.

r

I

I

I

?
,
in
UpPer,
take
-1
manifold

1
-1
Throttle
housing
(Heated)

q
:lZU

Fig
.
4
.



DISA
system
components
.
DISA
changes
the
intake
runner

length
based
on
engine
speed
.

The
DISA
system
electro-pneumatically
changes
the
intake
runner
length
through
the
twin-section
intake
manifold
and
a
change-over
butterfly
valve
.
The
change-over
valve
is
located
at
a
point
in
the
intake
manifold
where
four
pipes
come
into
two
.
When
the
change-over
valve
is
closed,
the
4-way
primary
intake
manifold
and
the
2-way
ram
air
manifold
areconnected
to
make
the
"long"
configuration
.
When
the
change-overvalve
opens,
intake
air
flow
is
redirected
through
only
the
short
4-

way
primary
intake
manifold
.

The
change-over
valve
is
held
in
the
normally
open
position
bya
spring
.
Thisallows
for
an
open
valve
in
the
event
of
sys-
tem
failure
.
During
low
andmid
enginespeeds,
the
DME
con-

trol
module
supplies
power
to
the
solenoid
valve,
which
in
turn

allows
vacuum
to
be
applied
lo
the
vacuum
diaphragm
.
This

causes
the
valve
to
close
(long-pipe
configuration)
.
When
en-
gine
speed
reaches
approximately
4,800
rpm,
the
DME
con-
trol
module
electrically
signals
the
solenoid
valve
and
the
valve
opens,
creating
the
short
pipe
configuration
:

Further
detafs
on
DISA
canbefound
in
130
Fuel
Injection
.

Engine
Management
System

Al¡
enginescoveredby
this
manual
usean
advanced
engine

management
system
called
Digital
Motor
Electronics
(DME)
.

In
the
DME
system,
advancedOn-Board
Diagnostics
(OBD),

fuel
injection,
ignition,
and
otherfunctions,
are
combined
under

the
control
of
theEngine
Control
Module
(ECM)
.
See
Fig
.
5
.

-



Lower
intake
manifold

DISAvacuum
'
~servo

EíY1z

ENGINE-GENERAL
100-
3

le

-
DISA
solenoid
valve

0012591

/
with
butterfly
va¡

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

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
.