engine mount BMW 328i 1997 E36 Workshop Manual

WARNING
-

"
Never
work
under
a
lifted
car
unless
it
is
solidly
supported
on
jack
stands
that
are
intended
for
that
purpose
.
Do
not
support
a
car
on
cinder
blocks,
bricks,
or
other
objects
that
may
shift
orcrumble
under
continuous
load
.
Never
work
un-
dera
car
that
is
supported
only
by
the
lifting
jack
.

"
Fuel
is
highly
flammable
.
When
working
around
fuel,
do
not
smoke
or
worknear
heaters
or
other
fire
hazards
.
Keepan
approved
fire
extinguisher
handy
.

"
llluminate
the
work
area
adequately
and
safely
.
Use
a
portable
safety
light
for
working
inside
or
under
thecar
.
A
fluorescent
type
lightis
best
be-
cause
it
gives
off
less
heat
.
If
using
a
light
with
anormal
incandescent
butb,
use
rough
service
bulbs
to
avoid
breakage
.
The
hot
filamentof
an
accidentallybroken
bulb
can
ignite
spilled
fuel
or
oil
"
Keep
sparks,
lighted
matches,
and
any
open
llame
away
from
thetop
of
the
battery
.
Hydrogen
gas
emitted
by
the
battery
is
highly
flammable
.
Any
nearby
source
of
ignition
may
cause
the
battery
to
explode
.

"
Never
¡ay
tools
or
parts
in
the
engine
compart-
ment
or
on
top
of
the
battery
.
They
may
fall
into
confined
spaces
and
be
difficult
toretrieve,
be-
come
caught
in
beits
or
other
rotating
parts
when
the
engine
is
started,
or
cause
electrical
shorts
anddamage
to
the
electrical
system
.

"
The
fuel
system
is
designed
to
retain
pressure
even
when
the
ignition
is
off
.
When
working
with
the
fuel
system,
loosen
the
fuel
fines
slowly
to
al-

low
the
residual
pressure
to
dissipate
gradually
.

Take
precautions
to
avoid
spraying
fuel
.

Lifting
the
Car

FUNDAMENTALS
FOR
THE
DO-ITYOURSELF
OWNER
010-
3

For
those
repairs
that
require
raising
the
car,
theproper
jack-

ing
points
should
beused
to
raise
thecar
safely
and
avoid
dam-

age
.
There
are
four
jacking
points
from
which
thecar
can
be

safely
raised
.
The
jacksupplied
with
thecar
by
BMW
can
only

be
used
at
the
fourside
points
just
behindthe
front
wheel
or

just
in
frontof
the
rear
wheel
.
See
Fig
.
1.

WARNING
-

"
When
raising
the
car
using
a
floor
jack
ora
hy-

draulic
lift,
carefully
position
the
jack
pad
topre-

vent
damaging
the
car
body
.
A
suitable
liner

(wood,
rubber,
etc
.)
should
be
placed
between
the
jack
and
the
car
to
prevent
body
damage
.

"
Watch
the
jack
closely
.
Make
sure
ft
stays
stable

and
does
not
shift
or
tilt
.
As
the
car
is
raised,
the
car
may
rol¡
slightly
and
the
jack
may
shift
.

Fig
.
1
.



3-Seriesjacking
points
(arrows)
.

Raising
car
safely

1
.
Park
car
on
flat,
leve¡
su
rface
.

2
.
Remove
the
round
cover
from
jack
mount
using
a

screwdriver
.
See
Fig
.
2
.

0013126

Fig
.
2
.



Jack
mount
cover
being
removed
from
rocker
panel
.

3
.
Place
jack
fully
into
position
.
See
Fig
.
3
.
Make
sure
jack

is
resting
on
flat,
solid
ground
.
Use
a
board
or
other
sup-

port
to
provide
a
firm
surface
for
the
jack,
if
necessary
.

4
.
Raisecar
slowly
while
constantly
checking
position
of

jack
and
car
.

5
.
Once
car
is
raised,
block
the
wheel
that
is
opposite
and

farthest
from
jackto
prevent
car
fromunexpectedly
roll-

ing
.

GET77NG
STARTER

Table
b
.
Inspection
I
Service

MAINTENANCE
PROGRAM
020-5

ad

d
d
ID

a



r



c



d
a~
;v
a
:
Q~
wE
y
a
r
E
R
:
L-



0
Maintenance
ítem



1



z



3
~



c
d

Engine
compartment
maintenance

Change
oil
and
oil
filter
.

Check
brake/clutch
fluid
leve¡

Check
battery
acid
leve¡
and
correct
asnecessary
.
Repair
Group
121

Check
engine
coolant
level
and
anti-freeze
protection
and
addasnecessary
.
Inspect
for
cooling
system
leaks
.
Repair
Group
170

Lubricate
throttie
linkage

Under
car
maintenance

Check
transmission
for
externa¡
leaks
.

Check
manual
transmission
oil
leve¡
andadd
asnecessary
.
Repair
Group
230

Check
final
drive
lubricant
and
addasnecessary
.

Check
fue¡
tank,
fuel
lines,
and
all
connections
for
leaks
.

Inspect
exhaust
system
.
Repair
Group
180

Check
steeringrack
and
steeringlinkages
.
Check
power
steering
system
for
leaks
.
Check
(luid
leve¡
.
Repair
Group
320

Inspect
brake
system
for
damaged
hoses
and
fines,
leaks
or
damage
.
Remove
calipers
and
check
brake
pad
wear
.
Check
brake
rotors
for
scoring
damage
.
Repair
Group
340

Check
parking
brake
operation,
adjust
cable
if
necessary
Repair
Group
340

Inspect
front
and
rear
suspension,
including
wheel
bearings,
for
play
.
Repair
Group
320/330

Inspect
wheelsand
tires,
including
spare,
check
tire
pressure
and
condition

Body
and
Interior
Maintenance

Lubricate
door
hinges
and
hood
latch,
hood
hinges

Check
headlight
and
driving
light
aiming
and
adjust
as
necessary
.

Check
operation
of
headlights,
parking
lights,
back-up
fights,
licenseplate
lights,
interior
lights,
glove
box
light,
engine
compartment
light,
trunk
light,
instrument
panel
lights,
turnsignals,
emer-gency
flashers,
stop
fights,
horas,
headlight
flasher
and
dimmer
switch

Replace
ventilation/A/C
micro-filter
.
Check
functionof
air
conditioning
.
Repair
Group
640

Check
function
of
seat
belts
.
Repair
Group
720

Check
tightness
of
mountfng
screws
on
airbag
front
crash
sensors
(Airbag
I)
.
Repair
Group
721

Check
windshield
washer
fluid
leve¡
and
concentration,
add
as
necessary
Check
operation
of
washer
system
.
Check
condition
of
wiperblades
.
Repair
Group
611

Tighten
nuts
and
bolts
for
door
locks
and
striker
plates

Replace
batteries
for
alarm/remote
control
in
masterkey(where
applicable)
.

Road
Test

Check
braking
performance,
steering,
HVAC,
manual
or
automatic
transmission,
and
mirrors

Service
Interval
Reset

Reset
service
indicator
using
specialreset
tool
.

MAINTENANCE
TALES

Final
Drive
Gear
Oil

BMW
recommends
using
only
a
specially
formulatedsyn-
thetic
gear
oil
that
is
available
through
an
authorized
BMW
dealer
parts
department
.
For
additional
information
on
this
¡u-
bricant
andany
other
lubricants
that
may
be
compatible,
con-
tact
an
authorized
BMW
dealer
senrice
department
.
See
331
Final
Drive
.

Brake
Fluid

Brake
fluid
absorbs
moisture
easily,
and
moisture
in
the
fluid
affects
brake
performance
and
reliability
.
This
is
why
brake
fluid
should
be
flushed
from
the
system
every
two
years
.
When
re-
placing
or
adding
brake
fluid,
use
only
new
(luid
from
previously
unopened
containers
.
Do
not
use
brake
fluid
that
has
been
bled
from
the
system,
even
ifit
is
brand
new
.
Use
only
DOT
4
brake
fluid
.
See340
Brakes
for
more
information
.

Engine
Coolant
(Anti-freeze)

BMW
recommends
coolant
that
is
a
50/50
mixture
of
distilled
water
and
phosphate/nítrate
freeanti-freeze
containing
ethyl-
ene
glycol
.
Anti-freezeraises
the
boiling
point
and
lowersthe
freezingpoint
of
the
coolant
.
It
alsocontains
additives
that
help
prevent
cooling
system
corrosion
.

Power
Steering
Fluid

The
power
steering
fluid
is
Dexron
II]®
ATF,
or
equivalent
.

The
system
is
permanently
filled
and
does
not
have
a
drain
.
Routinely
adding
ATF
is
not
required
unlessthe
system
is
leak-
i
n
g,

WARNING
-

Be
sure
to
check
the
fluid
specifications
on
the
pow-
er
steering
reservoir
to
confirm
the
fluid
type
in-
stalled
in
the
system
.
In
some
instances,
the
power
steering
system
may
be
filled
with
an
alternative
hy-
draulic
fluid
designated
CHF
7
.1
.

MAINTENANCE
PROGRAM
020-

ENGINE
OIL
SERVICE



Engine
oil
and
fiiter,
changing

Fig
.
3
.



Engine
oil
level
dipsticklocation
on
4-cylinder
engine
(arrow)
.
Dipsfck
is
marked
with
mínimum
and
maximum
level
marks
.

Fig
.
4
.



Oil
filler
cap
(arrow)
.
6-cylinder
engine
shown
.
0012202

Engine
oii,
checking
leve¡



A
complete
oil
change
requires
new
oil
(see
Table
e),
a
new
oil
filter
insert
kit,
and
a
new
drain
plug
sealing
washer
.
The

The
engine
oil
leve]
is
checked
with
a
dipstick
in
the
engine



tools
needed,
a
drain
plug
socket
or
box
wrench
(17
mm
or19

block
.
Check
the
oii
leve¡
with
the
canon
a
level
surface,
after



mm)
and
a
drain
pan
(8-10
US
qt
.
capacity),
are
described
in

the
engine
has
been
stopped
for
atleast
a
few
minutes
.
Check



010
Fundamentals
for
the
Do-It-Yourself
Owner
.

the
leve¡
by
pulling
outthe
dipstick
and
wiping
it
clean
.
Reinsert

it
all
the
way
and
withdraw
it
again
.
The
oil
leve¡
is
correct
if
it
is



NOTE-
between
the
two
marks
near
the
end
of
the
stick
.
See
Fig
.
3
.



If
using
a
"fast-lube"
service
facility
for
oil
changes,
make
sure
the
technician
hand-starts
and
torques
the
Add
oil
through
the
filler
cap
on
thetop
of
the
cylinder
head
.



engine
oil
drain
plug
using
hand-tools
.
Power
tools
can
See
Fig
.
4
.
Add
only
the
amount
needed
to
bring
the
oil
leve¡to



strip
the
threads
of
the
plug
and
the
oil
pan
.

the
MAX
mark
on
the
dipstick,
using
an
oil
of
the
correctviscos-
ity
andgrade
.
Too
much
oil
canbe
just
as
harmful
as
too
little
.

ENGINE
OIL
SERVICE

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
.

Accelerator
and
Throttle
Linkage

The
accelerator
and
throttie
linkage
should
be
lubricated
pe-
riodically
.
Use
a
general
purpose
oil
on
the
joints
and
bearings

of
the
linkage
.
Use
a
multipurpose
grease
on
the
bearing
points

of
the
throttie
plate
.

Engine
Drive
Belts

Drive
belts
and
pulleys
transfer
power
from
theengine
crank-

shaft
to
various
accessories
.
See
Fig
.
13
.
Depending
on
model

and
model
year,
engine
driven
accessories
are
driven
by
V-

belts,
poly-ribbed
(serpentine)
belts,
or
a
combination
of
the

two
.
For
example,
early
4-cylinder
engines,
usetwo
V-belts
and
one
poly-ribbed
belt
.

Inspect
drivebelts
with
the
engine
off
.
lf
the
belt
shows
signs

of
wear,
cracking,
glazing,
or
missing
sections,
it
should
be
re-

placed
immediately
.

V
belt,
replacing

(4-cylinder
engines
built
up
to
1194)

0012472

Fig
.
13
.
Drive
belt
and
tensioner
assembly
for
late
4-cylinder
engine
wíth
poly-ribbed
drive
belt
.

V-belts
should
be
inspected
during
regular
maintenance
in-

tervais
.
Incorrect
tension
can
decrease
the
life
of
the
belt
and

the
component
it
drives
.
The
V-belt
tension
is
adjusted
through

a
toothed-rack
mechanism
.

Inspect
belts
with
the
engine
off
.
Twist
the
beltto
inspect
its

sidewalls
and
bottom
.
Beltstructural
damage,
glazed
or
shiny

sidewaljs
caused
by
a
loose
belt,
orseparation
are
al¡
reasons

to
replace
a
belt
.

Replacement
of
the
V-belts
every
four
years
is
recommend-

ed
.
Loosen
the
mounting
bolts
and
adjust
the
belt-driven
unit

until
the
belt
tension
is
as
loose
aspossible
.
Remove
the
belt
by

slipping
it
over
the
pulleys
.
In
some
cases
it
may
be
necessary

to
removeone
V-belt
to
get
to
another
.
Use
a
torque
wrench
and

a
crowfoot
wrench
to
turn
the
tensioning
gear
bolt
and
set
belt

tension
.
Hold
the
wrench
steady
and
tighten
the
locknut
on
the

rear
of
the
tensioning
gear
bolt
.
Tighten
al¡
other
mounting
nuts
.

MAINTENANCE
PROGRAM



020-
1
3

NOTE-

"
For
the
most
accurate
check,
V-belt
tension
should
be
checked
using
a
V-belt
tension
gauge
.

"
Belt
squealing
is
normally
caused
by
loose
beltten-sion
.
Belt
dressings
should
not
be
used
.

Tightening
Torques

"
Tensioning
gear
(alternator

belt
tensioning)
.
.
.
...............
7
Nm
(62
in-lb)

"
Tensioning
gear(power
steering

belt
tensioning)
...
..
...
8
to
8
.5
Nm
(71
to
75
in-lb)

"
Tensioning
gear
locking
nut
.......
24
Nm
(18
ft-Ib)

NOTE-

When
belts
are
replaced
with
new
ones,
store
the
old
set
in
the
luggage
compartment
for
emergency
use
.

When
installing
a
new
belt,
gently
pry
it
over
the
pulleys
.
Too

much
force
may
damage
the
belt
or
the
accessory
.
Tension
the

belt(s),
runthe
engine
for
a
few
minutes
(at
least
1500
rpm),

then
recheck
the
belt
tension
.

CAUTION-

Do
not
over
tighten
the
V-belts
.
Overtightening
will
cause
shaft
bearings
to
fail
prematurely
.

Poly-ribbed
belt,
replacing

(4-cylinder
engines
buiit
from
1194

and
all
6-cylinder
engines)

An
automatic
belt
tensioner
is
used
to
keep
the
belts
ten-

sioned
properly
.
Unless
the
tensioner
mechanism
malfunc-

tions,
the
poly-ribbed
belts
do
not
require
tension
adjustment
.

To
reduce
the
chance
ofbelt
failure
while
driving,
replace-

ment
of
the
belts
every
four
years
is
recommended
.
Mark
drive

belt
rotationdirectíon
if
removing
and
reusing
an
old
belt
.

To
remove
the
belt,
it
is
necessary
toretract
the
self-tension-

er
.
Using
a
breaker
bar
or
other
long
socket
assembly,
rotate

the
tensioner
to
loosenthe
belt
.
See
Fig
.
14
or
Fig
.
15
.
On
4-cyl-

inder
engines,
it
will
benecessary
to
remove
the
A/C
compres-

sor
belt
to
remove
the
main
drive
belt
.

WARNING
-

Observe
care
when
replacing
the
belt
.
Personal
in-
jury
could
result
if
the
tensioner
springs
back
into
position
uncontrollably
.

With
the
belt
removed
from
the
pulleys,
inspect
the
pulleys

for
wear
or
damage
that
may
cause
early
failureof
the
new
belt
.

This
is
also
a
good
opportunity
to
inspect
the
belt-driven
acces-

sories,
checking
for
bearing
wear
and
excess
play
.
Drive
belt

routing
is
shown
in
Fig
.
16
and
Fig
.
17
.

ENGINE
COMPARTMENT
MAINTENANCE

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

020-
1
6



MAINTENANCE
PROGRAM

Fuel
filter,
replacing

Oxygen
sensor

(regulating)
\
Catalytic



Oxygen
sensor
convertor
(monitoring)

Fig
.
21
.
Typical
1996
and
later
exhaust
system
showing
oxygen
sensor
locations
.

UNDER-CAR
MAINTENANCE

convertor

On
early
4-cylínder
cars,
the
fuel
filter
is
mounted
under
the
caron
the
left
front
bulkhead
.
On
early
6-cylínder
cars,
the
fuel
filter
is
mounted
to
the
front
left
motor
mount
in
theengine
com-
partment
.
See
Fig
.
22
.

0013139
Fig
.
22
.
Fuel
filter
location
(arrow)
on
bulkheadunder
left
side
of
vehi-
cle
.
Filter
for
M42
engine
shown
.

On
later
cars,
the
fuel
filter
is
located
beneath
the
centerof
the
car,
approximately
under
the
driver's
seat
.
See
Fig
.
23
.
A
protective
cover
is
installed
overthe
fuel
filter,
which
must
be
re-
moved
to
access
the
filter
.

UNDER-CAR
MAINTENANCE

Exhaust
flap

actuator

(monitoring)

NOTE-

Drain
the
fuel
filter
trom
the
inlet
side
into
a
container
and
inspect
the
drained
fuel
.
Check
for
rust,
moisture
and
contamination
.

WARNING
-
Fuel
will
be
expelled
when
the
filter
is
removed
.
Do
not
smoke
or
worknear
heaters
or'other
fire
haz-ards
.
Keep
a
tire
extinguisher
handy
.

CAUTION-

Clean
thoroughly
around
the
filter
connections
be-
fore
removing
them
.

0012726
Fig
.
23
.
Fuel
filter
location
under
center
of
car
(arrow)
.
Filter
for
M52
engine
shown
.

Catálytic
\
Oxygen
sensor

When
replacing
the
fuel
filter,
disconnect
the
battery
negative
(-)
cable
and
clamp
the
filter
inlet
and
outlet
hoses
to
lessen
fuel
spillage
.
Loosen
thecenter
clamping
bracket
and
the
two
hoseclampson
either
end
of
the
filter
.
Note
the
arrow
or
mark-
ings
indicating
direction
of
flow
on
the
new
filter
.
Install
the
filter
anduse
new
hose
clamps
.

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

100-6
ENGINE-GENERAL

Cylinder
compression,
checking

A
compression
tester
is
needed
to
make
a
compression
test
.

To
obtain
accurate
test
results,
the
battery
and
starter
must
be
capable
of
cranking
the
engine
at
250-300
rpm,
and
theen-

gine
should
be
at
normal
operating
temperature
.
Use
com-

pressed
air
to
clean
aroundthe
spark
plugs
before
removal
.

1
.
Disable
the
ignítion
system
by
removing
the
engine

management
system
main
relay
and
the
fuel
pump
re-
¡ay
.
See
Fig
.
6
.

WARNING
-

The
ignítion
system
produces
high
voltages
that
canbe
fatal
.
Avoid
contact
with
exposed
termínals
and

useextreme
caution
when
working
on
acar
wíth
the
ignítion
switched
on
or
the
engine
running
.

Fuel



DM
E
pump
main
re
ay



rel
ay
o
oa
ooa

.,
o00
oao

Fig
.
6
.



Engine
management
relays
in
power
distribution
box
inleft
rear
of
engine
compartment
.

CAUTION-

"
On
OBD
11
cars,
making
a
compression
test
may
causea
faultto
set
in
the
ECM
and
may
also
il-
luminate
the
Check
Engine
light
.
The
light
can
only
be
tumed
out
using
special
scan
tool
equip-
ment,using
eíther
the
BMW
specialservíce
tool
or
using
a
"generic"
OBD
11
scan
tool
.
Discon-
necting
the
battery
will
not
erase
the
fault
mem-
orynor
turn
outthe
light
.

0013034,

0012630

Fig
.
7
.



Remove
spark
plug
wires
from
spark
plugs
on
4-cylinder
en-
gine
using
special
tool
.
Tool
is
stored
under
cover
at
rear
of
cylinder
head
(arrow)
.

Fig
.
8
.



Remove
engine
cover
on
6-cylinder
engine
byprying
off
nut
covers
and
removing
nuts
(A)
.
Be
careful
not
to
let
rubber
in-
sulators
fall
off
as
cover
is
removed
(arrows)
.

4
.
On
6-cylinder
engines,
disconnect
the
harness
connec-
tors
from
the
ignítion
coils
by
lifting
the
retaining
clip
.

Remove
the
coil
mounting
nuts
andremove
the
six
coils
.
See
Fig
.
9
.
Remove
the
sparkplugs
.
"
Failure
to
remove
the
main
relay
or
attempting
to
disable
the
ignítion
system
by
other
methods
may
resultin
damage
to
the
engine
control
module
.



NOTE-

Used
sparkplugs
should
be
reinstalled
in
the
same
cyl-

2
.
On
4-cylinder
engine
:
Remove
plastic
engine
cover
from



inder
fromwhich
they
were
removed
.

top
of
cylinder
head
.
Disconnect
spark
plug
wires
and
re-
move
spark
plugs
.
See
Fig
.
7
.



5
.
Insta¡¡
the
compression
gauge
in
the
first
cylinder's

3
.
On
6-cylinder
engine
:
Remove
top
engine
coverby
pry-



spark
plug
hole,
tight
enough
to
form
a
good
seal
.

ing
off
nut
covers
and
removing
mounting
nuts
.
See
Fig
.
8
.

MECHANICAL
TROUBLESHOOTING

eiioo4

Fig
.
9
.



Remove
ignition
coils
on
6-cylinder
engine
by
disconnecting
harness
connector
and
removing
mounting
bolts
(arrows)
.

NOTE-

"
The
compression
gauge
reading
shoutd
increase
with
each
compression
stroke
and
reach
near
its
maxi-
mum
reading
in
about
4-6
strokes
.

"All
cylinders
shoutdreach
maximum
compression
in
the
same
number
of
strokes
.
If
a
cylinder
needs
sig-
nificantly
more
strokes
to
reach
maximum
compres-

sion,
there
is
a
problem
.

7
.
Release
the
pressure
at
the
compression
gauge
valve,

then
remove
the
gauge
from
the
spark
plughole
.
Re-

peat
the
test
for
each
of
the
other
cylinders
and
com-

pare
the
results
with
the
values
given
below
.

ENGINE-GENERAL
1
:00-
7

Compression
Pressure

"
Minimum
..........
.
.
..
..
10-11
bar
(142-156
psi)

"
Maximum
difference
between
cylinders
..
.....
.........
0
.5
bar
(7
psi)

Reinstall
the
spark
plugs
and
spark
plug
wires
or
ignition

cofs
.
The
remainder
of
installation
is
the
reverse
of
removal
.
Be
sure
to
reihstall
al¡
wires
disconnected
during
the
test,
especial-

¡y
ground
wires
at
the
coils
and
cylinder
head
cover
(where
ap-
plicable)
.

Tightening
Torque

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

Low
compression
indicates
a
poorly
sealed
combustion

6
.
With
the
parking
brake
set,
the
transmission
in
Park
or



chamber
.
Relatively
even
pressures
that
are
below
specification

Neutral,
and
the
accelerator
pedal
pressed
to
the
floor,



normally
indicate
worn
piston
rings
and/or
cylinder
walls
.
Erratic

crank
the
engine
with
the
starter
.
Record
the
highest



values
tend
to
indicate
valve
leakage
.
Dramatic
differences
be

value
indicated
by
the
gauge
.



tween
cylinders
are
often
the
sign
of
a
failed
head
gasket,

bumed
valve,
or
broken
piston
ring
.

Engine
Mechanical
Troubleshooting
Table

Table
c
lists
the
symptoms
of
common
engine
mechanical

problems,
their
probable
causes
and
the
suggested
corrective

actions
.
The
bold
type
indicates
the
repair
groups
where
appli-

cable
test
and
repair
procedures
can
befound
.

MECHANICAL
TROUBLESHOOTING