diagnostic BMW 318i 1997 E36 Workshop Manual

We
have
endeavored
to
ensure
the
highest
degree
of
accuracy
possible
.
When
the
vast
array
of

data
presented
in
the
manual
is
taken
into
account,
however,no
claim
to
infallibility
can
be
made
.

We
therefore
cannotbe
responsible
for
the
result
of
any
errors
that
may
have
crept
into
the
text
.
The

publisher
encourages
comments
from
the
readers
of
this
manual
with
regard
to
any
errors
and,
al-

so,
suggestíons
for
improvement
in
the
presentation
of
technical
material
.
These
communications

have
been
and
will
be
carefully
considered
in
the
preparation
of
futureprintings
of
this
and
other

manuals
.
Please
contact
Robert
Bentley,
Inc
.
using
the
contact
information
on
the
copyright
page

at
the
beginning
of
this
manual
.

BMW
offers
extensive
warranties,
especially
on
components
of
the
fuel
delivery
and
emissions

control
systems
.
Therefore,
before
deciding
to
repair
a
BMW
that
may
still
be
covered
wholly
or
in

part
by
any
warranties
issued
by
BMW
of
North
America,
consult
your
authorized
BMW
dealer
.
You

may
find
that
hecan
make
the
repaireither
freeor
at
minimum
cost
.

Regardless
of
its
ageand
whether
or
not
it
is
still
protected
by
warranty,
your
BMW
is
aneasycar

to
get
serviced
.
So
if
at
any
time
a
repair
is
needed
that
you
feel
is
too
difficult
to
do
yourself,
a

trained
BMW
technician
is
ready
to
do
thejob
for
you
.
Each
authorized
BMW
dealer
senricedepart-

ment
has
made
a
significant
investment
in
service
and
diagnostic
test
equipment,
specials
tools,

and
BMW
original
parts
.
It
is
also
the
best
source
of
the
most
up-to-date
repair
and
service
tech-

niques,
which
includes
factory
training
and
technical
literature
.
Servicing
your
BMW
through
an
au-

thorized
BMW
dealer
will
insure
that
your
investment
will
be
protected
while
maintaining
the
highest

degree
of
service
standards
.

Robert
Bentley

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
.

Fig
.
16
.
Multimeter
or
Digital
Volt/Ohmmeter
(DVOM)
.

BMW
Special
Tools

FUNDAMENTALS
FOR
THE
DO-ITYOURSELF
OWNER
010-11

0012223

Some
of
the
more
challenging
repairs
covered
in
this
manual

cal¡
for
the
use
of
BMW
special
tools
.
This,
however,
does
not

automatically
mean
that
thejob
is
too
complicated
or
out
of

reach
of
thenovice
.

Many
of
the
BMW
special
tools
mentioned
in
this
manual
are
simplythe
best
thing
to
use
to
do
thejob
correctly
.
In
these
cas-

es,
the
tool
is
identified
with
a
BMW
part
number
.
See
your
au-

thorized
BMW
dealer
parts
department
for
information
on
how

to
order
special
tools
.

There
are
some
jobs
for
which
expensive
special
tools
are

essential,
and
not
a
cost-effective
purchase
for
one-time
repair

by
the
do-it-yourself
owner
.
This
manual
includes
such
repairs

for
the
benefit
of
these
with
the
necessary
experience
and
ac-

cess
to
tools
.
For
the
do-it-yourselfer,
the
need
for
special
tools

is
noted
in
the
text,
and
whether
or
not
BMW
dealer
service
is

recommended
.

EMERGENCIES

Changing
a
Tire

Stop
thecar
onas
flat
a
surface
as
possible,
in
a
place
where

you
canbe
easily
seen
by
other
drivers
.
Avoid
stopping
just

over
the
crest
of
a
hill
.
Turnon
the
emergency
flashers,
and
set

out
(lares
or
emergency
markers
well
behindthecar
.
Chock
the

wheel
(wheel
chock
located
in
trunk)
diagonally
opposite
to
the
one
being
changed
.
Passengers
shouldgetout
of
thecar
and

stand
well
away
from
the
road
.
Remove
the
spare
tire
from
the
spare
tire
storage
tray,
as
described
later
.

WARNING
-

If
a
tire
goes
fíat
while
drtving,
pull
well
off
the
road
.
Changing
a
tire
ona
busy
street
or
highway
is
very
dangerous
.
If
necessary,
drive
a
short
distance
on
the
fíat
tire
to
get
to
a
sale
place
.
tt
is
much
better
to
ruin
a
tire
or
rim
than
to
risk
being
hit
.

Take
the
jack
and
tools
from
the
tool
area
beneath
the
trunk

mat
.
Remove
the
spare
tire
from
the
tire
storage
tray
.

Loosen
the
wheel
bolts
while
the
car
is
on
the
ground,
but

leave
them
a
little
snug
.
Placethe
jack
in
the
lifting
point
nearest

the
wheel
beingchanged,
lifting
points
are
shown
in
Fig
.
1
and

Fig
.
2)
.
Use
a
board
to
provide
a
firm
footing
for
the
jack
if
the

ground
is
soft
.
Raise
the
car
only
lar
enough
so
that
the
wheel
is

fully
off
the
ground
and
then
remove
the
wheel
nuts
and
the

wheel
.

Insta¡¡
the
spare
wheel
.
Install
the
wheel
nuts
and
tighten

them
by
hand,
then
lower
the
car
.
With
all
wheelson
the

ground,
fully
tighten
the
nuts
in
a
crisscross
pattern
.
Torque
the

wheel
nuts
when
installing
the
wheel
.
Check
the
inflation
pres-

sure
of
the
spare
tire
.

Tightening
torques

"
Wheel
to
wheel
hub
.....
100
t
10
Nm
(74
t
7
ft-Ib)

Car
Will
Not
Start

If
the
engine
tucos
over
slowly
or
not
at
all,
especially
on
cold

mornings,
the
battery
may
not
be
sufficiently
charged
.
Jump-

starting
the
battery
from
another
car
may
help
.

WARNING
-

On
carswith
manual
transmisston,
push
starting
(or

tow
starting)
acar
ts
not
recommended
by
BMW
.

NOTE-

Be
sure
to
read
the
cautions
underJump
Starting
Car
prior
boosting
a
low
battery
.
Fatlure
to
followthe
cau-

tions
may
result
in
damage
to
the
electronic
compo-
nents
in
the
car
.

If
the
engine
is
turning
over
at
normal
speed
with
the
starter

motor,
the
battery
and
starter
are
fine
.
Check
to
make
sure
that

there
is
fuel
in
the
tank
.
Do
not
rely
on
the
fuel
gauge,
it
may
be

faulty
.
Instead,
remove
the
gas
filler
cap
and
rock
thecar
.
If

there
is
gas
in
the
tank,
you
should
hear
a
sloshing
sound
at
the

filler
neck
.
lf
there
is
plenty
offuel
in
the
tank,
see100
Engine-

General
for
in-depth
diagnostics
and
troubleshootingproce-

dures
.

EMERGENCIES

If
steam
is
coming
from
the
engine
compartment
thenthere
is



With
the
engine
and
ignition
off,
check
for
loose
or
corroded
most
likely
a
burst
coolant
hose
or
a
large
leak
in
the
cooling



battery
cables
or
wires
at
the
battery
or
thealtemator
.
Discon-
system
.
To
find
the
leak,
look
for
signs
of
coolant
leakage
on



necting,
cleaning,
and
reinstalling
corroded
wires
and
connec-
hoses,
at
hose
connections,
or
on
the
radiator
.
Let
theengine



tors
may
solve
the
problem
.
Also
check
drive
belt
tension
as
cool
thoroughly,
then
add
coolant
or
water
to
fill
the
system
and



described
in
020
Maintenance
Program
.
start
the
engine
.
If
a
great
deal
of
water
or
coolant
flows
out
of
the
hole,
then
thecarshouldnot
be
driven
until
repairs
are
made
.
lf
there
is
slight
seepage,
then
it
may
be
possible
to
drive



TOWi
ng

a
short
distance,
adding
coolant
as
needed
.
The
cars
covered
by
this
manual
should
be
towed
witha
tow
truck
using
wheel
lift
or
flat
bed
equipment
.
Do
not
tow
thecar
on
all
four
wheels
except
for
very
short
distances
to
move
it
to
a
safe
place
.
If
thered
engine
oil
pressure
warning
light
illuminates,
imme-
diately
stop
thecar
and
turn
off
the
engine
.
Have
the
vehicle



A
towing
eye
is
provided
in
the
luggage
compartment
tool
kit
.
flat-bedded
or
towed
to
an
authorized
service
center
and
have



The
towing
eye
can
be
screwed
into
the
front
or
rear
bumper
.
the
engine
oil
pressure
checked
.



See
Fig
.
18
and
Fig
.
19
.

Low
Oil
Pressure

NOTE-

Detafed
information
on
checking
the
oil
pressure
is
covered
ín
119
Lubrication
System
.

Brake
Fluid
Leve¡

The
brake
fluid
leve¡
warning
light
may
bean
indicator
of
brake
fluid
loss
.
Problems
with
the
brakesystem
should
be
checked
and
repaired
immediately
.
See
340Brakes
for
more

information
.

Check
Engine
Warning
Light

Dim
Lights

FUNDAMENTALS
FOR
THE
DO-IT
YOURSELF
OWNER



010-13

If
the
"CHECK
ENGI
NE"
warning
light
comes
on
or
flashes,
it
indicates
that
an
emissions-related
fault
has
occurred
.
Faults
suchas
a
failed
oxygen
sensor
or
a
faultyfuelinjector
can
tum

the
light
on,
causing
the
exhaust
or
evaporative
emissions
to

exceed
a
specified
limit
.
The
engine
can
be
safely
driven
with

the
light
on,
although
the
emission
systems
should
be
checked

assoonas
possible
.
See
100
Engine-General
for
more
infor-

mation
on
the
Check
Engine
Light
and
the
On-board
diagnostic

system
.

Headlights
and
instrument
panel
illuminationthat
are
dim
or

gradually
getting
dimmer
generally
indicate
a
problem
with
the

battery
or
charging
system
.
The
battery
charge
indicator
light

may
come
on
as
the
lights
are
dimming
.
In
either
case,
theen-

gine
and
accessories
are
running
off
of
the
battery
alone,
and

will
soon
discharge
it
altogether
.

If
possible,
do
not
stop
the
engine
unless
you
have
the
capa-

bility
to
jump
start
¡t
.
There
may
not
be
enough
power
in
the

starting
system
torestart
the
engine
.
Instead,turn
off
as
many

electrical
consumers
as
possible
.
This
will
reduce
the
current

drain
and
will
allow
thecar
to
be
driven
farther
before
you
lose

all
battery
power
.

Fig
.
18
.
Pry
open
rear
tow
lúg
access
panel
.

When
towingthecar
from
the
front
with
the
rear
wheelson

the
ground,
a
maximum
distance
of
20
miles
is
acceptable
.
If

thecar
needs
to
be
towed
further,
have
the
rear
wheels
placed
on
dollies
.

CA
UTION-

"
Do
not
tow
with
sling-type
equipment
The
front
spoilers
andbumper
covers
may
sustain
dam-
age
.

"
Towínga
BMW
with
an
automatic
transmission
with
the
rear
wheelson
the
ground
can
resuft
in
transmission
damage
due
to
lackof
lubrication
and
should
be
avoided
.

0013128

EMERGENCIES

NOTE-



Aftermarket
reset
tools
can
be
purchased
from
one
of
the
fol-
lift
owng
manuacurers
:
For
referente,
the
BMW
Inspection
1
and
Inspection
11
requirements
are
approximately
equivalent
to
the
main-
tenance
requirements
that
other
European
manufac-



Assenmacher
Bo
s
turers
specify
.
Inspection
I
is
normally
due
at
intervals



lder,
CO
80301

Specialty
Tools

with
a
maximum
of
15,000
miles
or
12
months
.
lnspec-



(303)
530-2424

tion
11
is
normally
due
at
intervals
with
a
maximum
of
30,000
miles
or
24
months
.



Peake
Research,Automotive
Products
Division
P
.O
.
Box
28776

San
Jose,
CA
95159

Resetting
Service
Indicator



(408)
369-0406

When
the
specified
maintenance
has
been
carried
out,
the
service
indicator
memory
should
be
reset
.



MAINTENANCE
TABLES

The
senrice
indicator
is
reset
using
a
special
tool
.
The
tool
is
plugged
into
the
diagnostic
connector
in
the
engine
compart-

ment
.
See
Fig
.
2
.

iii

Fig
.
2
.



Service
indicator
reset
tool
installed
in
diagnostic
connector
(aftermarket
tool
shown)
.

CAUTION-

Follow
themanufacturer's
directions
when
reset-
ting
the
service
Indicator
.
If
the
reset
procedures

are
done
incorrectly,
the
reset
tool
or
the
electron-
ic
service
indicator
may
be
damaged
.

MAINTENANCE
PROGRAM
020-
3

Table
a,b,c,
and
don
the
following
pages
list
the
routine
maintenance
tasks
specified
by
BMW
.
The
intervals
for
most
of
thesetasks
are
determined
by
the
Service
Indicator
.
The
main-

tenance
intervals
for
afew
additional
items
are
based
on
either
elapsedmileage
ortime
.
These
intervals
are
indicated
in
sepa-
rate
tables
.

Except
where
noted,
the
maintenance
items
listed
apply
to
all
models
and
model
years
coveredby
this
manual
.
The
columns

on
the
rightsitie
of
each
table
give
quick-referente
information

about
the
job
.
The
bold
text
references
the
repair
groups
where

additional
repair
information
can
befound
.

MAINTENANCE
TABLES

Fig
.
18
.
Fill
mark
on
coolant
expansion
tank
.
Coolant
level
should
be

at
mark
when
engine
ís
cold
.

.
..
e
..
.-
..



~
..
.-
.

Ozone
Damaged
Hose

0012476

Fig
.
19
.
Examples
of
damage
to
coolant
hoses
.
Any
of
conditions

shown
is
cause
for
replacement
.
Courtesy
of
Gates
Rubber
Company,
Inc
.

Specification

"
Power
steering
fluid
..........
.
...
Dexron
III®ATF

Oxygen
Sensors

1996
and
later
engines
are
equipped
withmultiple
oxygen

sensors
.
See
Fig
.
21
.
A
regulating
sensor
is
mounted
before

each
catalytic
converter
and
amonitoring
sensor
downstream

of
each
converter
.
The
regulating
sensor
monitors
engine
com-

bustion
efficiency
and
helps
to
control
the
fuel
injection
system

and
exhaust
emissions
.
The
monitoring
sensor
is
usedby
the

On-board
diagnostic
system
to
monitor
the
function
of
the
cata-

lytic
converter
.

MAINTENANCE
PROGRAM



020-
1
5

NOTE-

5pecialsockets
for
replacingthe
oxygen
sensor
are

available
from
most
automotive
parts
stores
.
The
sock-

et
has
agroove
cut
down
one
side
to
allow
the
sensor

to
be
installed
without
damaging
the
wire
hamess
.

Fig
.
20
.
Power
steering
fluid
dipstick
showing
MIN
and
MAX
marks
.

OBD
II
enhanced
emission
standards
require
the
engine

control
module
(ECM)
to
monitor
the
oxygen
content
in
theex-

haust
bothbefore
and
after
the
catalytic
converter
.
This
allows

for
tightercontrol
of
the
tail
pipe
emissions
and
also
allowsthe

ECM
to
diagnose
converter
problems
.
lf
the
DME
detects
that

catalytic
converter
or
oxygen
sensor
efficiency
has
degraded

past
a
certain
pre-programmed
limit,
it
will
turn
on
the
Check

Engine
light,
and
store
a
diagnostic
trouble
code
(DTC)
in
the

ECM
.

Replacement
of
oxygen
sensors
at
the
specified
intervals
en-

sures
that
the
engine
and
emission
control
system
wíll
continue

to
operate
as
designed
.
Extending
the
replacement
interval

may
void
the
emission
control
warranty
coverage
.
See
180
Ex-

haust
System
for
information
on
replacing
the
oxygen
sen-

sors
.

Tightening
Torque

"
Oxygen
sensor
to

exhaust
system
........
.
.
.
..
55±5
Nm
(40±4
ft-Ib)

ENGINE
COMPARTMENT
MAINTENANCE

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

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

ignition

Table
b
.
Engine
Management
Systems



engine
has
high
mileage
.

Engine



1
System

4-cylinder
engines
M42
(1992-1995)



Bosch
DME
Ml
.7
M44
(1996-1998)



Bosch
DME
M5
.2
(OBD
II)

6-cylinder
engines
M50
(1992)



Bosch
DME
M3
.1
M50
VANOS
(1993-1995)



Bosch
DME
M3
.3
.1
M52
(1996-1998)



Siemens
MS41
.1
(OBD
II)
S50US
(1995)



Bosch
DME
M3
.3
.1
S52US
(1996-1998)



Siemens
MS41
.1
(OBD
II)

Both
the
4-cylinder
and
6-cylinder
engines
use
a
distributor-

less
ignition
system
with
individual
ignition
coils
for
each
cylin-

der
.

FuelDelivery

Pressurized
fuel
from
the
in-tank
fuel
pump
is
injected
via

solenoid-type
fuel
injectors
.
The
ECM
controls
the
opening

and
closing
of
the
injectors
by
switchingthe
ground
side
of

each
injector
circuit
.
The
exact
amount
of
fuel
injected
is
de-

termined
by
the
amount
of
timethe
injectors
are
open
.

Cooling
System

Whenever
the
engine
is
running,
acoolant
pump
circulates

coolant
through
the
engine
and,
if
either
heater
control
valves

are
open,
through
the
heater
core
in
the
passenger
compart-

ment
.
The
coolant
absorbs
excess
heat
and
carries
it
to
the
ra-

diator
where
it
is
transferred
into
the
passing
airstream
.
A

thermostat
controls
the
flow
of
coolant
through
the
radiator

based
on
engine
temperature
.

Lubrication
System

The
lubrication
system
is
pressurized
whenever
theengine

is
running
.
The
oil
pump
draws
oil
through
a
pickup
in
the
bot-

tom
of
the
oil
pan,thenforces
it
through
a
replaceable
oil
filter

and
finto
the
engine
oíi
passages
.

On
4-cylinder
engines,
the
oil
pump
is
mounted
to
the
front

engine
cover
.
On
6-cylinder
engines,thechain-driven
oil

pump
is
bolted
to
the
bottom
of
the
cylinder
block
.

A
pressure
relief
valve
limits
the
maximum
system
pres-

sure
.
A
bypass
valve
prevents
the
oil
filter
from
bursting
and

insures
engine
lubrication
should
the
filter
become
plugged
.

See
119
Lubrication
System
for
additional
information
.

ENGINE-GENERAL
100-
5

Various
versions
of
DME
systems
are
usedon
thecars
cov-



MECHANICAL
TROUBLESHOOTING
ered
by
this
manual
.
See
Table
b
.
Each
system
is
highly
adaptive
to
compensate
for
things
suchasengine
wear
and



When
troubleshooting
an
engine
that
fails
to
start
or
runs
vacuum
leaks
.



poorly,
first
check
its
mechanical
condition-particularly
if
the

Warnings
and
Cautions

For
personal
safety,
as
well
asthe
protection
of
sensitive
electronic
components,
the
following
warnings
and
cautions
must
be
adhered
to
during
all
troubleshooting,
maintenance,
and
repairwork
.

WARNING
-

"
The
ignition
system
produces
high
voltages
that
can
be
fatal
.
Avoid
contact
with
exposed
termi-
nals
anduse
extreme
caution
when
working
on
a
car
with
the
ignition
switched
on
or
the
engine
running
.

"
Do
not
touch
or
disconnect
any
high
voltage
ca-
bles
from
the
coil,
distributor,
orspark
plugs
while
the
engine
is
running
or
being
cranked
by
the
starter

"
Connect
and
disconnect
the
engine
manage-
ment
system
wiring
and
test
equipment
leads
only
when
the
ignition
is
switched
off
.

"
Gasoline
is
highly
flammable
and
its
vapors
are
explosive
.
Do
not
smoke
or
work
on
a
car
near
heaters
or
other
fire
hazards
when
diagnosing
and
repairing
fuel
system
problems
.
Have
a
fire
extínguisher
available
in
case
of
an
emergency
.

"
Disconnecting
the
battery
may
erase
fault
code(s)
stored
in
control
module
memory
.
Using
special
BMW
diagnosnnc
equipment,
check
for
fault
codes
prior
to
disconnecting
the
battery
cables
.
If
the
Check
Engine
lightis
illuminated,
see
On-

Board
Diagnostics
(OBD)
forfault
code
infor-
mation
.
If
any
other
system
faults
havebeen
de-tected
(indicated
byan
illuminated
warning
light),
see
an
authorized
BMW
dealer
.

CAUTION-

"
Prior
to
disconnecting
the
battery,
read
the
bat-
tery
disconnection
cautions
gíven
at
the
front
of
this
manual
on
page
viii
.

"
Do
notconnect
any
test
equipment
that
delivers
a
12-volt
power
supply
to
terminal15
(+)
of
the
ignition
coil
.
The
current
flow
may
damage
the

ECM
.
In
general,
connect
test
equipment
only
as
specified
by
BMW,
this
manual,
or
the
equip-
ment
maker
.

"
Do
not
disconnect
the
battery
with
the
engine
running
.
Do
notrunthe
engine
with
any
of
the
sparkplug
wires
disconnected
.

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
.