1994 BMW M3 warning

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

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
.

Tires,
checking
inflation
pressure



Brake
pad/rotor
wear,
checking

Correct
tire
pressuresare
important
to
handling
and
stability,



Al¡
E36
cars
are
fitted
withdisc
brakes
at
al¡
four
wheels
.
See
fuel
economy,
and
tire
wear
.
Tire
pressures
change
with
temper-



Fig
.
24
.
Although
thebrakesare
equipped
with
a
brake
pad
ature
.
Pressures
should
be
checked
often
during
seasonal
tem-



warning
system,
the
system
only
monitors
one
wheel
per
axle
.
perature
changes
.
Correct
inflation
pressures
canbe
found
on



It
is
recommended
that
pad
thickness
should
be
checked
the
driver's
door
pillar
and
in
the
owner's
manual
.
Note
that
tire



whenever
the
wheels
are
off
or
brakework
is
beggg
done
.
pressuresshould
be
higher
when
thecar
is
more
heavily
loaded
.

WARNING
-

Do
not
inflate
any
tire
to
a
higher
pressure
than
the
tiress
maximum
ínflation
pressure
listed
on
the
side-
wall
.
Use
cara
when
addlng
air
to
warm
tires
.
Warm
tire
pressures
can
increase
as
much
as4
psi
(0.3
bar)
over
their
cold
pressures
.

Tires,
rotating

BMW
does
not
recommend
tire
rotation
.
Due
to
the
cars
sus-
pension
design,
the
fronttires
begin
to
wear
first
at
the
outer

shoulder
and
the
rear
tires
begin
to
wear
first
at
themiddle
of

the
tread
or
inner
shoulder
.
Rotating
the
tires
may
adversely
af-

fect
roadhandling
and
tire
grip
.

NOTE-

The
main
purpose
of
tire
rotation
isto
promote
even
wear
and
maximum
tire
life
.
Tire
life
may
be
decreased
slightly
if
the
tires
are
not
rotated
.

Wheels,
aligning

Routine
maintenance
of
the
brake
system
includes
maintain-

ing
the
brake
fluid
in
the
reservoir,
checking
brakepads
for

wear,
checking
hand
brake
functíon,
and
inspecting
the
system

for
fluid
leaks
or
other
damage
.

Check
that
brake
hoses
are
correctly
routed
to
avoidchafing

or
kinkíng
.
Inspect
unions
and
brake
calipers
for
signs
of
fluid

leaks
.
Inspect
rigid
fines
for
corrosion,
dents,
or
other
damage
.

Inspect
flexible
hoses
for
cracking
.
Replace
faulty
hoses
or
lines
as
described
in
340Brakes
.

WARNING
-

Incorrect
installation
or
overtightening
hoses,
fines,

and
unions
may
cause
chafing
or
leakage
.
This
can
lead
to
partíal
or
completebrake
system
failure
.

MAINTENANCE
PROGRAM



020-
1
7

B323

Fig
.
24
.
Disc
brake
pad
wear
can
checked
through
opening
in
caliper
.

The
brake
caliper
should
be
unbolted
from
the
suspension

strut
to
properly
inspect
the
brake
pads
and
the
rotors
.
See
Fig
.

25
.
Brake
caliper
removal
and
installation
procedures
are
given
in
340
Brakes
.
BMW
recommends
checking
the
front
and
rear
alignment

once
a
year
and
whenever
new
tires
are
installed
.
See320

Steering
and
Wheel
Alignment
for
a
more
detailed
discus-

sion
of
alignment
requirements
and
specifications
.

Brake
Pad
Lining
Minimum
Thickness

(Dimension
A)

Brake
system,
inspecting



"
Front
and
reardisc
brake
pads
....
3
.0
mm
(0
.12
in)

Brake
fluid,
replacing

BMW
strictly
recommends
replacing
the
brake
fluid
every
two
years
.
This
will
help
protect
against
corrosion
and
the
ef-

fects
of
moisture
in
the
(luid
.
See340
Brakes
for
brake
fluid

flushing
procedures
.

Parking
brake,
checking

The
parking
brakesystem
is
independent
of
the
main
braking

system
and
may
requireperiodic
adjustment
dependingon
use
.
Adjust
the
parking
brake
if
the
brake
lever
can
be
pulled
up

more
than
8
clicks
.
Check
that
the
cable
moves
freely
.
A
de-

scription
of
the
parking
brake
and
parking
brake
adjustment

can
be
found
in
340Brakes
.

UNDER-CARMAINTENANCE

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

020-20



MAINTENANCE
PROGRAM

Seat
Belts



Washing
Chassis

Dirt
and
other
abrasive
particles
will
damage
seat
belt
web-



Periodic
washing
of
the
underside
of
the
car,
especially
in

bing
.
If¡t
is
necessary
to
clean
seat
belts,
use
a
mild
soap
solu-



winter,
will
help
prevent
accumulation
of
road
salt
and
rust
.
The

tion
.
Bleach
and
other
strong
cleaning
agents
may
weaken
the



besttime
to
wash
the
underside
is
just
after
the
car
has
been

belt
webbing
and
should
be
avoided
.



driven
in
wet
conditions
.
Spray
the
chassis
with
a
powerful
jet
of

water
.
Commercial
or
self-service
car
washes
may
not
be
best

WARNING-



for
this,
as
they
may
recycle
the
salt-contaminated
water
.

Do
not
clean
the
seat
belt
webbing
using
dry
clean-
ing
or
other
chemicals
.
Allow
wet
belts
to
dry
before
allowing
them
to
retract
.



Speeial
Cleaning

The
condition
of
the
belt
webbing
and
the
function
of
the
re-

tractor
mechanisms
should
be
inspected
.
See720
Seat
Belts
for
seat
belt
inspection
information
.

Exterior
Washing

The
longer
dirt
isleft
on
the
paint,
the
greater
the
risk
of
dam-
aging
the
glossy
finish,
either
by
scratching
or
by
the
chemical
effect
dirt
particles
may
have
on
the
paintedsurface
.

Do
not
wash
the
car
in
direct
sunlight
.
If
the
engine
hood
is

warm,
allow
it
to
cool
.
Beads
of
water
not
only
leavespots
when
dried
rapidly
by
the
sun
or
heat
from
the
engine,
but
also
can
act
as
small
magnifyingglasses
and
burn
spots
into
the
finish
.
Wash
thecar
with
a
mixture
of
lukewarmwater
and
a
car
wash
product
.
Rinse
using
plenty
of
clear
water
.
Wipe
the
body
dry
witha
soft
cloth
towel
or
chamois
to
prevent
water-spotting
.

Waxing

For
a
long-lasting,protective,
and
glossy
finish,
apply
a
hard
wax
after
thecar
has
been
washed
and
dried
.
Use
carnauba
or
synthetic
based
products
.
Waxing
is
not
needed
after
every
washing
.
You
can
tell
when
waxing
is
required
by
looking
at
the
finísh
when
it
is
wet
.
If
the
water
coats
the
paint
in
smooth
sheets
instead
of
forming
beads
that
rol¡
off,
a
new
coat
of
wax
is
needed
.
Wax
shouldnot
be
applied
to
black
trim
pieces,
rub-
ber,or
other
plastic
parts
.

Polishing

Use
paintpolish
only
if
the
finish
assumes
a
dull
lock
after
long
service
.
Polish
can
beused
to
remove
tar
spots
and
tar-
nish,
but
afterwards
a
coat
of
wax
should
be
applied
to
protect
the
clean
finish
.
Do
not
use
abrasive
polish
or
cleaners
on
alu-
minum
trimor
accessories
.

BODYAND
INTERIOR
MAINTENANCE

Cylinder
Head
and
Valvetrain

The
aluminum
cylinder
head
uses
chain-driven
double

overhead
camshafts
and
four
valves
per
cylinder
.
See
Fig
.
1
.
Tha
rvfinriar
hand
nmnlnve
n
ernceflnier
rineinn
fnr
nronter

Tar
spots
canbe
removed
with
a
bugand
tar
remover
.
Never

use
gasoline,
kerosene,
nail
polish
remover,
or
other
unsuitable

solvents
.
Insect
spots
also
respond
to
tar
remover
.
A
bit
of
bak-

ing
soda
dissolved
in
the
wash
water
will
facilitate
their
removal
.
This
method
can
also
beused
to
remove
spotting
from
tree
sap
.

Interior
Care

Dirt
spots
can
usually
be
removed
with
lukewarm
soapy
wa-
ter
or
a
dry
foam
cleaner
.
Use
spot
remover
for
grease
and
o¡I

spots
.
Do
not
pour
the
(quid
directly
on
the
carpetor
fabric,
but
dampen
a
clean
cloth
and
rub
carefully,starting
at
the
edge
of
the
spot
and
working
inward
.
Do
not
use
gasoline,
naptha,
or

other
flammable
substances
.

Leather
Upholstery
and
Trim

Leather
upholstery
and
trim
should
be
periodically
cleaned
using
a
slightly
damp
cotton
or
wool
cloth
.
The
idea
is
to
get
rid
of
the
dirtin
the
creases
and
pores
that
can
cause
brittleness
and
premature
aging
.
On
heavily
soiled
areas,
usea
mild
deter-
gent
(such
as
Woolite®)
or
other
specially
formulated
leather
r

cleaners
.
Use
two
tablespoons
to
one
quart
of
cold
water
.
Dry

the
trim
and
upholstery
completely
using
a
soft
cloth
.
Regular
use
of
agood
quality
leather
conditioner
will
reduce
drying
and
crackingof
the
leather
.

1
.
Camshafts
2
.
Rocker
arms
3
.
Hydraulic
valve
adjusters
(HVA)
4
.
Valve
and
conical
valve
spring

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

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