1993 BMW M3 coolant

d
a
d
_
L

G>
G1
a
N
.






G1
Ñ



N
N
O
.
r
d

Maintenance
ítem



°
~



Z



~
i
I
D
i
Body
and
Interior
Maintenance
(cont
.)

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

Check
function
of
seat
belts
.
Repair
Group
720

Check
windshield
washer
fluid
level
and
concentration,
add
asnecessary
.
Check
operation
of
washer
system
.
Check
condition
of
wiperblades
Repair
Group
611

Tighten
nuts
and
belts
for
door
locks
and
striker
plates
.

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

Check
ground
connection
(mounting
screws)
of
SRS
(airbag)
front
sensor
to
body,
if
applicable
.
Repair
Group
721

Road
Test

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

Service
Interval
Reset

Reset
service
indicator
using
specialreset
tool
.

Maintenance
ítem

Replace
oxygen
sensor
.
Repair
Group
180
1992-1994
1995-
on

Flush
and
replace
brake
fluid/clutch
fluid
.
Repair
Group
340

Drain
and
flush
cooling
system
and
replace
coolant
.
Repair
Group
170
1992-19961997-1998

Anti-corrosion
warranty
inspection
.

Tablec
.
Inspection
II
Service
(continued)

Cabled
.
Scheduled
Maintenance-Time/Mileage
Intervais

MAINTENANCE
PROGRAM
020-7

e
~
e
e

i
:
l=
N



l
"
r
NM
I
«)

al



aN



-
11



>

O
Ó



I
Ó



I`
Ó

d
Ny
.
0



°
_



VÑ



Ñ



Ñ
1
ZG

NN

MAÍNTENANCE
TABLES

020-
8



MAINTENANCE
PROGRAM

FLUID
AND
LUBRICANT
SPECIFICATIONS
The
fluids
and
lubricante
specified
by
BMW
are
listed
in
Ta-

ble
e
.
Shown
below
is
engine
oil
viscosity
(SAE
grade)
vs
.
oper-

ating
temperature
range
for
the
BMW
enginescovered
in
this

manual
.

Engine
Oil
Viscosity
Requirements

vs
.
Temperature

`S
EAVic
P
Q
SAE
swao

YCO

0

N

M42
engine



1
.1
I
(1
.2
US
qt
.)
M44
engine



1
.1
l(1.2
US
qt
.)
M50
engine



1
.1
1(1.2
US
qt
.)
M52
engine



1
.21(1.3
US
qt
.)
S50US
engine



1
.21(1.3
US
qt
.)
S52US
engine



1
.21(1.3
US
qt
.)

°F
80

-

1o-0
-
30
-----20

WARNING
-

The
use
of
fluids
that
do
not
meet
BMWs
specifica-
tions
may
impair
performance
and
refability,
and
may
void
warranty
coverage
.

Tablee
.
Fluids
and
Lubricants

0013227

Fluid
Approximate
Specification
capacity

Engine
oil
with
filter
change

M42
engine



5
.01
(5
.3
US
qt
.)
M44
engine



5
.0
I
(5
.3
US
qt
.)
M50
engine



6
.5
I
(6.9
US
qt
.)



API
service
SH
or
M52
engine



6
.51
(6.9
US
qt
.)



si
S50US
engine



6
.51
(6.9
US
qt
.)
S52US
engine



6.0
I
(6.3
US
qt
.)

Manual
transmission
oil

FLUID
AND
LUBRICANT
SPECIFICATIONS

See
230Manual
Transmission
for



NOTE-
fluid
specification

Tablee
.
Fluids
and
Lubricants
(continued)

Fluid
Approximate
Specification
capacity

Automatic
transmission
fluid
(ATF)
(drain
and
fill)
(additional
fluid
required
when
installing
a
drytorque
converter)

A4S
310R



See240
AutomaticTransmission
for
fluid
A4S
270R



specification
information
A5S
310Z

Final
drive
(drain
and
fill)
(Lifetime
fluid
;
no
fluid
change
required)

4-cylinder



1
.1
I
(1.2
US
qt
.)



BMW
SAF-XO
6-cylinder



1.7
l(1
.8
US
qt
.)



synthetic



oil



(ex
.
limited
slip)
BMW
SAF-X1-S
synthetic
oil
(limit-
ed
slip)

Power
steering
fluid

Al¡
modeis



permanentlysealed



Dexron
IIPATFno
drain
plug

rake
fluid

All
modeis



-
~
S
AE
Dot4

Engine
coolant

M42
engine



6
.51(6
.9
US
qt
.)
M44
engine



6
.51(6
.9
US
qt
.)
M50
engine



10
.51
(11
.1
US
qt
.)



50%
BMW
anti-
M52
engine



10
.5
1
(11
.1
US
qt
.)



freezel
50%
water
S50US
engine



10
.75
1(11
.4
qt
.)
S52US
engine



10
.75
I
(11
.4
qt
.)

CA
UTION-

Multi-viscosity
engine
oils
should
not
beused
in
the
manual
transmission
.
Use
of
such
an
oil
could
shorten
the
service
life
of
thetransmission
.

Manual
Transmission
Fluid

The
manual
transmissions
installed
in
the
E36
modeis
are

normallyfilled
with
automatic
transmission
fluid
(ATF),
although

alternative
synthetic
lubricants
may
havebeen
used
from
-
the

factory,
depending
on
transmission
type
and
model
year
.
Con-

sult
230
Manual
Transmission
for
additional
information
on

identifying
the
type
of
fluid
installed
.

Automatic
Transmission
Fluid

The
automatic
transmissions
installed
in
the
E36
modeis
are
normally
filled
with
Dexron
111
automatic
transmission
fluid

(ATF),
although
alternative
fluids
havebeen
installed
from
the

factory,
depending
on
transmission
type
and
model
year
.
Some
transmission
are
filled
with
a
special
BMW
"life-time"
automatic
transmission
fluid,
whích
does
not
requireperiodic
fluid
changes
.
Consult
240
Automatic
Transmission
for
ad-
ditional
fluid
specification
information
.

information



1



The



11-



11
lubrican
type
canbefound
on
ti
¡e
`Yype
plate"
on
the
side
of
the
transmission
.
Consult
an
authorized
BMW
dealer
foralternate
fluid
use
and
the
Continued



most-up-to-date
information
regarding
transmission
op-
erating
fluids
.

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
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
.

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

100-4
ENGINE-GENERAL

'



TEMP

PRECAT



POST
CAT



OXYGENSENSOR
HEATING

#
.
THROTTLE
POSITION



FUEL
INJECTOR
CONTROL
(SEQUENTIAL)

OPERATING
POWER



00

CAMSHAFT
POSITION
SENSOR

ECM



I
MAIN
GROUND

RELAY



J_



-



AC
COMPRESSOR
RELAY
CONTROL

TERMINAL
15

MEMORY
POWER
FUEL
PUMP
RELAY
CONTROL
AUX
GROUND
P

CRANKSHAFT
POSITION
dESENSOR

INTAKE
AIR

ENGINE
COOLANT
TEMP

FUEL
TANK
PRESSURE
SENSOR

S-EML
S-MSR

ASC
S-ASC

VEHICLE
SPEED

LOW
FUEL
LEVEL

A/C
SWITCH
ON
(AC)
E36
IHKA
COMPRESSOR"ON"

SIGNAL
(KO)

INDIVIDUAL
SERIAL
NUMBER

MS41
.1

SECONDARY
AIR
1NJECTION
AIR
PUMP®
RELAY
CONTROL

IDLE
CONTROL
VALVE



'M

FUEL
INJECTION
(TI)

ENGINE
SPEED
(TD)

Fig
.
5
.



Siemens
MS
41
.1
OBD
II
engine
management
systemusedon
1996
and
later
M52
engines
.

GENERAL

IGNITION
COILS
CONTROL

L
r"Q
if~
CIYVFIYC



CHE
AMP
CONTROL
ENGINE

THROTTLE
POSITION

6

ECM
RELAY
CONTROL

ASC

THROTTLE
..
:
.
.
..
-11



1Q\\\
POTENTIOMETER
POWER

CAN



TCM
II



SCAN
(DES
;
ER

DIAGNOSIS

OBD
II
I
II

GENERIC
SCANTOOL



0012596

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