electric system cooling BMW 325i 1992 E36 Workshop Manual
Page 3 of 759
General
Data
and
010
FundamentalsfortheDo-lt-YourselfOwner
Maintenance
020
Maintenance
Program
Engine
Transmission
Suspension,
Steering
and
Brakes
4
Body
100
Engine-General
110
Engine
Removal
and
Installation
113
Cylinder
Head
Removal
and
Installation
116
Cylinder
Head
and
Valvetrain
117
Camshaft
Timing
Chain
119
Lubrication
System
200
Transmission-General
210
Clutch
230
Manual
Transmission
510
Exterior
Trim,
Bumpers
520
Seats
Bo
y
Equipment
512
DoorWTdws
540
nr
t
513
InteriorTrim
541
Convertible
Top
515
Central
Locking
and
Anti-Theft
600
Electrical
System-General
620
Instruments
Electrical
S
stem
610
Electrical
Component
Locations
630
Exterior
Lighting
611
Wipers
and
Washers
640
Heating
and
Air
Conditioning
6
612
Switches
and
Electrical
Accessories
650
Radio
Equipment
and
720
SeatBelts
Accessories
721
Airbag
System
(SRS)
Electrical
Wiring
Diagrams
Foreword
.
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v
Warnings
and
Cautions
.....
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Index
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back
of
book
300
Suspension,
Steering
and
330
RearSuspension
Brakes-General
331
Final
Drive
310
Front
Suspension
340
Brakes
320
Steering
and
Wheel
Alignment
400
Body-General
411
Doors
410
Fenders,
Engine
Hood
412
Trunk
Lid
120
Ignition
System
121
Battery,Starter,
Alternator
130
Fue¡
Injection
160
Fuel
Tank
and
Fuel
Pump
170
Radiator
and
Cooling
System180
Exhaust
System
240
Automatic
Transmission
250
Gearshift
Linkage
260
Driveshaft
Page 20 of 759
010-12
FUNDAMENTALSFOR
THE
DO-IT
YOURSELF
OWNER
Jump
Starting
Car
Cars
with
discharged
or
dead
batteries
can
be
jump-started
using
the
good
battery
from
another
car
.
When
jump-starting
the
engine,
always
note
the
following
warnings
.
WARNING
-
"
Battery
acid
(electrolyte)
can
cause
severe
burns,
and
will
damage
the
car
and
clothing
.
lf
electrolyte
is
spilled,
wash
the
surface
with
large
quantities
of
water
.
lfit
gets
finto
eyes,
flush
them
with
water
for
severa¡
minutes
and
cal¡
a
doctor
.
"
Batteries
produce
explosive
and
noxious
gas-
ses
.
Keep
sparks
and
flames
away
.
Do
not
smoke
near
batteries
.
"
Do
not
jump-start
the
engine
if
you
suspect
that
the
battery
is
frozen
.
Trapped
gas
may
explode
.
Allow
the
battery
to
thaw
first
.
"
Do
not
quick-charge
the
battery
(for
boost
start-
ing)for
longer
than
one
minute,
and
donot
ex-
ceed
15
volts
at
the
battery
with
the
boosting
cables
attached
.
Wait
at
least
one
minutebefore
boosting
the
battery
a
second
time
.
"
Some
electrical
system
'comfort"
features
may
not
function
correctly
once
battery
power
is
restored
.
For
example,
the
front
window
one-touch-up
func-
tion
may
be
disabled
.
Some
electrical
systems
will
need
to
be
reinitialized
Consult
the
appropriate
re-
pairgroup
formore
specific
information
.
1
.
Place
cars
close
together,
but
do
not
allow
them
to'touch
each
other
.
Turn
off
the
engine
of
thecar
with
the
good
battery
.
2
.
Connect
oneend
of
the
positive
(+)
cable
to
the
positive
(+)
post
of
the
good
battery
.
Remove
the
coverfromthe
positive
(B+)
junction
post
in
the
engine
compartment
of
the
dead
car
and
connect
the
other
end
of
the
posi-
tive
(+)
cable
to
the
junction
post
.
See
Fig
.
17
.
EMERGENCIES
3
.
Connect
one
end
of
the
negative
(-)
cable
to
the
nega-
tive
(-)
battery
post
of
the
good
battery
.
Connect
oppo-
site
end
of
the
negative
cable
(-)
to
the
engine
block
of
thecar
with
the
dead
battery
.
4
.
Start
thecar
with
the
good
battery
and
runthe
engine
at
about2,000
rpm,
then
start
the
car
with
the
dead
bat-
tery
.
5
.
With
the
engine
at
¡dle,
switch
on
the
headlights,
blower
motor
and
rear
window
defogger
to
avoid
damaging
the
cars
electrical
system
.
Carefully
disconnect
the
jumper
cables,
starting
with
the
negative
cable
on
the
engine
block
.
Turn
all
electrical
consumers
off
.
NOTE-
The
engineshould
be
run
for
at
least
an
hour
to
re-
charge
the
battery
.
Overheating
lf
the
temperature
gauge
needle
goes
into
the
red
band
on
the
gauge
face,
the
coolant
temperature
is
too
high
.
Find
a
safe
place
to
stop
and
turn
the
engine
off
.
Open
the
hood
and
allow
the
engine
to
cool
until
the
temperature
gauge
needle
is
at
the
lower
thirdof
the
scale
.
Continuing
to
drive
an
overheated
car
can
cause
extensive
engine
damage
.
WARNING
-
Do
not
remove
the
coolant
reservoir
or
radíator
cap
with
the
engine
hot
.
Undoing
either
couldspray
hot
coolant
and
cause
burns
or
damage
the
engine
.
CAUTION-
Do
not
add
cold
water
or
coolant
to
a
hot
engine
.
Engine
damage
could
result
from
the
sudden
tem-
perature
change
.
NOTE-
If
the
enginecannot
be
safely
tumed
off,
make
sure
the
air
condifioner
isoff
and
turn
the
heater
to
high
.
This
will
helo
cool
the
engine
until
a
salestopping
place
canbe
reached
.
Overheating
may
be
caused
bylow
coolant
leve¡
or
a
dam-aged
engine
drive
belt
.
Visually
check
the
coolant
leve¡
and
en-
gine
belts
as
described
in
020
Maintenance
Program
.
lf
the
coolant
leve¡
is
low,
check
the
filler
cap,hoses,
clamps
and
ra-
diator
for
signs
of
leakage
.
Check
for
leaks
at
the
water
pump
on
the
frontof
theengine
.
lf
no
leaks
are
found,
add
coolant
after
the
engine
has
cooled
.
The
carcan
be
driven,
but
have
the
cooling
system
thoroughly
checked
assoonas
possible
.
lf
replacement
cool
0013245
-
ant
is
not
available,
then
plain
water
canbe
used,
butthe
cool-
antshould
later
be
drained
and
refilled
with
theproper
mixture
Fig
.
17
.
Battery
jump
starting
posts
(arrows)
behind
right
frontstrut
of
anti-freeze
and
water
.
tower
.
Lift
cover
to
access
positive
post
.
Page 21 of 759
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
Page 28 of 759
020-6
MAINTENANCE
PROGRAM
Group
310/330
Table
c
.
Inspection
II
Service
a
d
d
a
a>
0
d
a
r
.c
mm
L
m
y
L
E
ó
3
E
ó
Maintenance
ítem
l
o-
z
~
c
Engine
compartment
maintenance
Inspect
V-belt
/Poly-ribbeddrive
condition
.
Check
V-belt
tension,
if
applicable
.
Lubricate
throttle
linkage
.
Replace
air
filter
.
Change
oil
and
oil
filter
.
Replacespark
plugs
.
Repair
Group
120
Check
brake/clutch
fluid
leve¡
.
Check
battery
acid
leve¡
and
correct
asnecessary
.
Repair
Group
121
Check
engine
coolant
leve¡
and
anti-freeze
protection
and
add
asnecessary
.
Inspect
for
cooling
system
leaks
.
Repair
Group
170
Under
car
maintenance
Change
automatic
transmission
fluid
.
Repair
Group
240
Change
manual
transmission
oil
.
Repair
Group
230
Check
clutch
plate
for
wear
.
Repair
Group
210
Check
drive
axle
boots
for
leaks
.
Repair
Group
330
Change
final
drive
fluid
(1995
and
later
models
:
change
synthetic
oil
every
2nd
Inspection
II)
.
Replace
fuel
filter
.
Check
fuel
tank,
fuel
lines,
and
af
connections
for
leaks
.
Inspect
exhaust
system
.
Repair
Group
180
Check
steering
gear
and
steering
¡inkages
.
Check
power
steering
system
for
leaks
.
Check
fluidleve¡
.
Repair
Group
320
Inspect
brake
system
for
damaged
hoses
and
lines,
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
.
Check
thickness
of
parking
brake
lin-
ings
.
Repair
Group
340
Inspect
front
and
rear
suspension,
including
front
and
rear
wheel
bearings,
for
play
.
Repair
Inspect
wheels
and
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
asnecessary
.
Check
operation
of
headlights,
parking
lights,
back-up
lights,
licenseplate
lights,
interior
lights,
glove
box
light,
engine
compartment
light,
trunk
light,
instrument
panel
lights,
turn
signals,
emer-gency
flashers,
stop
lights,
horns,
headlight
flasher
anddimmer
switch
.
Check
active
check
control
panel
forfauits
(where
applicable)
.
6
Electrical
System
MAINTENANCE
TABLES
Continued
on
next
page
Page 60 of 759
110-2
ENGINE
REMOVAL
AND
INSTALLATION
8
.
Drain
engine
coolant
andremove
coolant
hoses
at-
10
.
Remove
radiator
cooling
fan
and
radiator
as
described
tached
to
cylinder
head
.
in
170
Radiator
and
Cooling
System
.
"
Drain
radiator
and
engine
block
.
See
170
Radiator
and
Cooling
System
.
NOTE-
"
Disconnect
hoses
from
thermostat
housing
at
front
of
Some
late
4-cylinder
modelsuse
an
electric
prímary
cylinder
head
.
cooling
fan
.
"
Disconnect
heater
hoses
at
rear
of
engine
.
See
Fig
.
2
.
CAUTION-
NOTE-
On
cars
with
viscous-type
cooling
fans,
the
radia-
"
The
block
drain
plug
is
located
on
the
exhaust
side
to-
tor
fan
has
left
hand
threads
.
wards
rear
of
engine
.
"
Remove
small
plastic
lock
clíp
to
pull
radiator
drain
11
.
Remove
upper
intake
manifold,
unfasten
cable
duct
plug
out
completely
.
from
lower
intake
manifold,
crankcase
vent
valve
hose
(M44
engine
only)
0012687
Fig
.
2
.
Coolant
hoses
at
heater
valve
and
heatercore
to
be
discon-
nected
(arrows)
.
9
.
Remove
air
shroud
from
top
of
radiator
.
See
Fig
.
3
.
ENGINE
REMOVAL
AND
INSTALLATION
12
.
Disconnect
fuel
supply
and
fuel
return
lines,
main
en-
gine
electrical
connectors,
and
lower
intake
manifold
as
described
in
113
Cylinder
HeadRemoval
and
Instal-
lation
.
See
Fig
.
4
.
0012504
Fig
.
4
.
Crankcase
ventvalve
(A)
on
top
of
lower
intake
manifoldof
M44
engine
.
Fueldelivery
and
retum
lines
shown
at
B
.
Engine
harness
and
sensor
connectors
shown
at
C
.
WARNING
-
"
Fuel
may
be
expelled
under
pressure
.
Do
not
smoke
orworknear
heaters
or
other
fire
haz-
ards
.
Keep
a
fire
extinguisher
handy
.
Before
dis-
connecting
fuel
hoses,
wrap
a
cloth
around
fuel
hoses
to
absorb
any
leaking
fuel
.
Plug
all
open
fuel
lines
.
"
Always
unscrew
the
fuel
tank
cap
to
release
pres-
sure
in
the
tank
before
working
on
the
tank
or
lines
.
CAUTION-
0013137
I
Stuff
clean
rags
into
the
open
intake
ports
topre-
Fig
.
3
.
Front
air
shroud
mounting
screws
(arrows)
.
vent
any
parts
from
falling
into
the
engine
intake
.
13
.
Disconnect
vacuum
hose
from
brake
booster
on
bulk-
head
.
Cover
bothhole
in
booster
and
plug
hose
end
.
Page 110 of 759
117-
1
4
CAMSHAFT
TIMING
CHAIN
22
.
Installation
of
remaining
parts
is
reverse
of
removal,
When
theengine
is
running,
the
piston
housing
is
supplied
noting
the
following
:
with
pressurized
engine
oil
.
At
idie,
the
solenoid
isin
the
off
"
When
installing
thermostat,
make
sure
arrow
or
vent
position
(de-energized)
and
valve
timing
is
maintained
in
the
hole
faces
up,
if
applicable
.
normal
position
:
When
the
solenoid
is
energized,
the
gear
cup
"
Refill
cooling
systemas
described
in
170
Radiator
piston
moves
forward
to
advance
the
camshaftby
a
maximum
and
Coming
System
.
of
12
.5
.
"
Install
oil
pan
as
described
in
119
Lubrication
Sys-
tem
.
"
Fill
engine
with
oil
and
install
a
new
oil
filter
as
de-
scribed
in
020
Maintenance
Program
.
"
Insta¡¡
ground
wires
at
cylinder
head
cover
mounting
studs
and
at
front
of
cylinder
head
and
thermostat
housing,
where
applicable
.
VANOS
system
operation,
testing
Tightening
Torques
There
are3
special
tools
required
to
check
VANOS
opera-
"
Coolant
drain
plugto
cylinder
block
.
.
25
Nm
(18
ft-Ib)
tion
;
an
electricaltest
lead
(BMW
special
tool
no
.
12
6
410),
an
"
Radiator
cooling
fan
to
coolant
pump
.
40
Nm
(30
ft-Ib)
air
line
fitting
(BMW
special
tool
no
.
11
3
450),
and
a
crank-
"
Radiator
drain
screw
to
radiator
...
.
2
.5
Nm
(22
in-Ib)
shaft
TDC
locking
tool
(BMW
special
tool
no
.
112
300)
.
"
Upper
timing
chaincover
to
cylinder
head
The
test
leal
is
used
to
power
the
solenoid,
simulating
the
M6
nut
...
.....
.............
..
.
10
Nm
(89
in-lb)
ground
signal
from
the
DME
control
unit
.
The
air
line
fitting
M8
bolt
.....
....
.
.
.............
22
Nm
(17
ft-Ib)
takes
the
place
of
the
oil
supply
line
fitting
to
simulate
oil
Ares-
"
VANOS
control
unit
to
cylinder
head
sure
.
The
locking
tool
positions
and
locks
the
crankshaft
at
M6
nut
.........
..
..
.
..........
10
Nm
(89
in-lb)
TDC,
cylinder
no
.
l.
M8
bolt
........
...
.............
22
Nm
(17
ft-Ib)
"
VANOS
oil
supply
pipe
to
VANOS
control
unit
1
.
Remove
alternator
cooling
air
duct
.
banjo
bolt
.......
..
..
.
..........
32
Nm
(24
ft-Ib)
VANOS
(VARIABLE
VALVE
TIMING)
3
.
Remove
top
plastic
enginecovers
.
Disconnect
ignition
coil
harness
connectors
fromcofs
.
Remove
ignition
1993
and
later
6-cylinder
engines
are
equipped
with
a
vari-
coils
.
able
valve
timing
system
called
VANOS
.
This
system
is
con-
trolled
by
the
engine
management
system
and
dynamically
4
.
Remove
cylinder
head
cover
mounting
bolts
and
re-
adjusts
intake
camshaft
timing
based
on
engine
load,
engine
move
cylinder
head
cover
.
Unclip
andremove
oil
baffle
speed
and
engine
temperature
.
cover
from
above
intake
camshaft
.
See
113
Cylinder
Head
Removal
and
installation
.
The
main
components
of
the
VANOS
system
are
the
control
unit
with
piston
housing
and
integral
spool
valve,
and
the
mod-
ified
intake
camshaft
.
See
Fig
.
35
.
VANOS
(VARIABLE
VA
LVE
TIMING)
Fig
.
35
.
VANOS
control
unit
with
modified
intake
camshaft
.
B11001
WARNING
-
Special
BMW
service
tools
are
required
to
check
and
repair
the
VANOS
System
.
Read
theproce-
dures
through
before
beginning
the
job
.
2
.
Disconnect
crankcase
ventilation
hose
fitting
from
cyl-
inder
head
cover
.
NOTE-
Note
the
arrangement
of
the
cylinder
head
cover
bolt
insulators
and
gaskets
during
removal
.
5
.
Set
engine
to
approximate
TDC
by
rotating
in
normal
operating
direction
until
camshaft
lobes
at
cylinder
no
.
1
are
facing
each
other
.
See
Fig
.
20
.
6
.
Set
engine
to
TDC
by
aligning
"0/T"
mark
(0°TDC)on
front
vibration
damper
withcast
boss
on
lower
timing
chain
cover
.
See
Fig
.
21
.
7
.
Lock
crankshaft
in
position
by
inserting
BMW
special
tool
no
.
11
2
300
through
transmission
bellhousing
and
into
hole
in
flywheelor
driveplate
.
See
Fig
.
36
.
NOTE-
Confirm
that
the
locking
tool
has
been
correctly
in-
stalled
by
trying
to
rotatethe
crankshaft
.
Page 195 of 759
170
Radiator
and
Cooling
System
GENERAL
.
.
.....
.
...
.
.
.
.
.
....
.
.
.
.
.
.
.
.170-1
Coolant
Pump
and
Thermostat
........
.
.
.
.
170-1
Radiator
and
Expansion
Tank
.........
.
...
170-1
Cooling
Fans
.
....
.
.
.
.
.
.
.
.
.
.....
.
......
170-2
Warnings
and
Cautions
.
.
.
.
.
.
.
.
.
.
.
.
...
.
.
.
170-2
TROUBLESHOOTING
...
.
.
.
...
.
.
.
.
.
.
.
.
.170-2
Cooling
System
Pressure
Test
...
.
.
.
.
.
.
.
.
.
170-3
Thermostat
Quick
Check
.
.
.
.
...
.
.
.
.
.
.
.
.
.
170-3
Temperature
Gauge
Quick
Check
.
.
.
.
.
.
.
.
.
170-3
Cooling
fan,
testing
.
.
.
.
........
.
.
.
.
.
.
.
.
.
170-4
COOLING
SYSTEM
SERVICE
.
.
.
.
.
.
.
.
.
.
170-5
Coolant,draining
and
filling
.
.
......
.
.
.
.
.
..
170-5
Cooling
system,
bleeding
(radiator
with
integral
expansion
tank)
.....
170-6
GENERAL
This
section
covers
repair
and
troubleshooting
information
for
the
engine
cooling
system
.
For
heater
core
and
related
heating
and
air
conditioning
components,
see640
Heating
and
Air
Conditioning
.
Coolant
Pump
and
Thermostat
A
centrifuga¡-type
coolant
pump
is
mounted
to
the
front
of
the
engíne
.
The
belt-driven
pump
circulates
coolant
through
the
system
whenever
the
engíne
is
running
.
A
thermostat
con-
trols
the
flow
of
coolant
into
the
radiator
.
When
the
engíne
is
cold
the
thermostat
is
closed
so
coolant
bypasses
the
radiator,
recirculating
from
the
engíne
directly
back
to
the
pump
.
When
the
engíne
reaches
operating
tem-
perature,
the
thermostat
opens
and
coolant
circulates
through
the
whole
system
including
the
radiator
.
Radiator
and
Expansion
Tank
The
radiator
is
a
crossflow
design
.
A
translucent
expansion
tank
provides
for
coolant
expansion
at
higher
temperatures
and
easy
monitoringof
the
coolant
leve¡
.
On
4-cylinder
modeis,
the
radiator
expansion
tank
is
integral
with
the
radiator
.
See
Fig
.
1
.
RADIATOR
AND
COOLING
SYSTEM
170-1
Belt-driven
cooling
fan,
replacing
.
.......
.
.
.
170-7
Electric
cooling
fan,
replacing
.
.
.
.....
.
.
.
.
.
170-8
Auxiliary
cooling
fan,
replacing
.
.
.....
.
.
.
.
.
170-8
Thermostat,
replacing
.
.
.
.
.
.
.
.
.
.....
.
.
.
.
.
170-9
Coolant
pump,
replacing
..........
.
.
.
.
.
.
170-10
RADIATOR
SERVICE
.....
.
......
.
.
.
.
.
.
170-11
Radiator,
removing
and
installing
....
.
.
.
.
.
.
170-11
TABLES
a
.
Coolant
Temperature
Sensor
Wire
Colors
...
.
..
.
.
170-3b
.
Auxiliary
Cooling
Fan
Switching
Temperatures
.:.
.170-4
c
.
Auxiliary
Cooling
Fan
Temperature
Switch
Tests
..
..
.
...
...
.
.............
.
..
.
.
170-5d
.
Cooling
System
Capacities
..............
..
.
.
.
170-6
A
.
Expansion
tank
C
.
Dualtemperature
fan
switch
B
.
Radiator
drain
screw
Fig
.
1
.
Radiator
assembly
with
integral
expansion
tank
(4-cylinder
engine)
.
On
6-cylinder
models,
a
standalone
expansion
tank
is
used
.
On
cars
with
automatic
transmission,
ATF
is
circulated
through
an
additional
heat
exchanger
(ATF
cooler)
.
GENERAL
Page 196 of 759
170-2
RADIATOR
AND
COOLING
SYSTEM
Cooling
Fans
TROUBLESHOOTING
Belt-driven
coolingfan
.
The
primary
cooling
fan
is
belt-
driven
.
It
is
mounted
to
the
frontof
the
coolant
pump
through
a
fan
clutch
.
The
fan
clutch
is
a
viscous
fluid
coupling
that
con-
trols
the
speed
of
thefan
based
on
engine
compartment
tem-
perature
.
Electric
cooling
fan
.
Models
with
M44
engine
and
stan-
dard
transmission
substitute
an
electric
fan
for
the
belt-driven
viscous
fan
.
This
is
attached
to
the
rear
of
the
radiator
and
controlledvia
the
DME
5
.2
engine
management
system
.
NOTE-
The
electric
cooling
fan
in
these
models
is
activated
by
the
engine
control
module
(ECM)
.
Auxiliary
coolingfan
.
In
al¡
models
a
two-speed
electric
auxiliary
cooling
fan
is
mounted
behind
the
front
grill
and
in
front
of
the
radiator
.
This
fan
is
primarily
used
for
the
A/C
sys-
tem,
but
also
operates
when
the
coolant
temperature
ex-
ceeds
a
predetermined
leve¡
.
Warnings
and
Cautions
The
following
warnings
and
Cautions
should
beobserved
when
working
on
the
cooling
system
.
WARNING
-
"
Atnormal
operating
temperature
the
cooling
sys-
tem
is
pressurized
.
Allow
the
system
to
cool
as
long
as
possible
before
opening-a
minimum
of
an
hour-then
release
the
cap
slowly
to
allow
sale
release
of
pressure
.
"
Releasing
the
cooling
system
pressure
lowers
the
coolants
boiling
point
and
the
coolant
may
boíl
suddenly
.
Use
heavy
gloves
and
wear
eye
and
laceprotection
to
guard
against
scalding
.
"
Use
extreme
care
when
draining
and
disposing
of
engine
coolant
.
Coolant
is
poisonous
and
lethal
to
humans
and
pets
.
Pets
are
attracted
to
coolant
because
of
its
sweet
smell
and
taste
.
Consult
a
veterinarian
immediately
if
coolant
is
ingested
byan
animal
.
CAUTION-
"
Avoidadding
cold
water
to
the
coolant
while
the
engine
is
hot
or
overheated
.
If
it
is
necessary
to
add
coolant
to
ahot
system,
do
so
only
with
the
engine
running
and
coolant
pump
tuming
.
"
Prior
to
disconnecting
the
battery,
read
the
bat-
tery
disconnection
cautions
given
at
the
front
of
this
manual
on
page
viii
.
TROUBLESHOOTING
Most
cooling
system
faults
can
be
grouped
into
one
of
three
categories
:
"
Cooling
system
leaks
"
Poor
coolant
circulation
"
Radiator
cooling
fan
faults
When
investigating
the
cause
of
overheating
or
coolant
loss,
begin
with
a
visual
inspection
.
Be
sure
to
check
the
con-
dition
and
tension
of
the
coolant
pump
drive
belt
.
Check
hoses
for
cracks
or
softness
.
Check
clamps
for
looseness
.
Check
the
coolant
leve¡
and
check
for
evidence
of
coolantleaks
from
the
engine
.
Check
that
the
radiator
fins
are
not
blocked
with
dirt
or
de-
bris
.
Clean
the
radiator
using
low-pressure
water
or
com-
pressed
air
.
Blow
outward,
fromthe
engine
side
out
.
Inspect
the
coolant
pump
by
first
removing
the
drive
belt
from
the
pump
.
Firmly
grasp
opposite
sídes
of
the
pulley
and
check
for
play
in
all
directions
.
Spin
the
pulley
and
check
that
the
shaft
runs
smoothly
.
NOTE-
The
coolant
provides
lubrication
for
the
pump
shaft,
soan
occasional
drop
of
coolant
leaking
from
the
pump
is
acceptable
.
If
coolant
drips
steadily
from
the
vent
hole,
the
pump
should
be
replaced
.
The
cooling
system
becomes
pressurized
at
normal
operat-
ing
temperature,
which
raises
the
boiling
point
of
the
coolant
.
Leaks
may
prevent
the
system
from
becoming
pressurized,
allowing
the
coolant
to
boil
at
a
lower
temperature
.
If
visual
ev-
idence
is
inconclusive,
a
cooling
system
pressure
test
can
help
to
pinpointhard-to-find
leaks
.
If
the
cooling
system
is
full
of
coolant
and
holds
pressure,
the
next
most
probable
cause
of
overheating
are
:
"
Faulty
radiator
fan
"
Loose
or
worn
drive
belt
"
Failed
thermostat
or
coolant
pump
"
Clogged/plugged
radiator
or
coolant
passages
.
NOTE
-
"
Some
early
style
coolant
pumps
were
fitted
wíth
fi-
berlplastic
type
impellers
.
Over
time,
this
impeller
can
wear
away
and
result
in
overheating
.
The
plastic
im-
peller
can
also
slip
or
free-wheel
on
the
pump
shaft
.
If
the
engine
overheats
and
no
other
faults
canbe
found,
theold
style
impeller
may
be
the
cause
of
the
problem
.
"
Only
pumps
with
the
updated
metal
impeller
should
be
used
for
replacement
.
Page 198 of 759
170-
4
RADIATOR
AND
COOLING
SYSTEM
A
quick
testat
the
coolant
temperature
gauge
sender
can
The
auxiliary
cooling
fan
comes
on
when
coolant
tempera
determine
if
the
gauge
is
functioning
correctly
.
ture
exceeds
a
predetermined
leve¡
or
whenever
the
air
condi-
tioning
is
on
.
A
dual-range
temperature
switch
for
cooling
fan
lf
the
gauge
needie
remains
at
the
rest
position
with
theen-
control
is
mounted
on
the
right
side
of
the
radiator
.
See
Fig
.
3
.
gine
warm,
remove
the
harness
connector
from
the
sender
and
jumper
the
correct
terminals
in
the
connector
to
simulate
a
high
engine
temperature
.
See
Table
a
.
Turn
the
ignition
on
.
If
the
gauge
needle
moves
upward,
the
sender
is
faulty
.
If
the
gauge
does
not
respond,
the
wiring
to
the
gauge
is
broken
(open
circuit)
or
the
gauge
itselfis
faulty
.
WARNING
-
1996
and
laten
models
are
OBD
11
compliant
.
Dis-
connecting
electrical
connectors
wíth
the
ignition
turned
on
may
set
fault
codes
in
the
ECM
.
It
is
rec-
ommended
that
you
leave
the
diagnosis
of
faults
in
the
coolant
temperature
sensorsystem
to
the
BMW
dealer
service
department
which
has
specialized
OBD
11
scan
tool
equipment
.
If
the
gauge
needle
reads
too
high
when
the
engine
is
cold,
remove
the
harness
connector
from
the
sender
.
Turn
the
igni-
tion
on
.
lf
the
gauge
needle
position
does
not
change,
the
wir-
ing
or
the
gauge
is
shorted
to
ground
.
If
the
gauge
needle
drops,
the
sender
is
faulty
and
should
be
replaced
.
When
re-
placing
a
faulty
coolant
temperature
sender,
the
gasket
ring
on
the
sender
should
also
be
replaced
.
Tightening
Torque
"
Temperature
gauge
sender
to
engine
18
Nm
(13
ft-Ib)
Cooling
fan,
testing
NOTE-
OnM44
engines
with
manual
transmission,
the
primary
electric
cooling
fan
is
mounted
on
the
engine
side
of
the
radiator
and
is
controlled
by
the
engine
control
module
(ECM)
.
Troubleshooting
thiscircuit
should
be
left
to
an
authorized
BMW
dealer
with
the
proper
diagnostic
equipment
An
otherwise
sound
cooling
system
may
still
overheat,
par-
ticularly
with
prolonged
idling,
due
to
a
failure
of
the
coolíng
fan(s)
.
The
belt-driven
cooling
fan
is
controlled
by
a
temperature
dependent
viscous
clutch
.
A
failed
fan
clutch
may
affect
air
flow
through
the
radiator
resulting
in
overheating
orpossibly
overcooling
.
Speed
Low
sp
High
s
With
the
engine
off,
check
thefan
clutch
by
spinning
thefan
.
eed
The
fan
should
spin
on
the
clutch
with
some
resistance
.
peed
Check
for
signs
of
leaking
fluid
from
the
clutch
.
If
thefan
free-
wheels
with
no
resistance,
cannot
be
tu
rned
by
hand,
or
there
are
signs
of
oil
leakage,
the
clutch
should
be
replaced
.
TROUBLESHOOTING
Fig
.
3
.
Radiatorcooling
fan
temperature
switch
(arrow)
.
WARNING
-
"
Use
caution
when
testing
the
electric
cooling
fan(s)
and
coolant
temperature
switch
.
Keep
hands
and
wires
clear
of
thefan
blades
.
The
cool-
ing
fan(s)
can
run
any
time
the
ignition
is
ON
.
"
For
greatest
safety,
coolíng
fan
and
coolant
tem-perature
switch
tests
shouldbe
performed
on
acoldengine
with
the
air
conditioning
off
.
Table
b
.
Auxiliary
Cooling
Fan
Switching
Temperatures
Switching
temperature
196°F(91°C)
210°F(99°C)
0012506
If
a
faulty
thermostat,
trapped
air,
or
a
restriction
in
the
sys-
tem
is
not
allowing
the
coolant
to
circulate
through
the
radia-
tor,
the
temperature
switch
will
not
close
and
the
auxiliary
cooling
fan
will
not
run
.
Before
making
the
tests
described
be-
low,
make
sure
the
thermostat
is
operating
correctly
as
de-
scribed
earlier
.
The
normal
switching
temperatures
for
the
dual
-speed
switch
are
listed
in
Table
b
.
Page 199 of 759
NOTE-
Some
cars
covered
by
this
manual
may
have
an
alter-
nate
cooling
fan
switchwith
switching
temperatures
of
176%190W
(80%88°C)
.
When
replacing
the
switch
check
theswitching
specifications,
whichshouldbe
stamped
on
the
switch
body
.
1
.
If
coolant
is
circulating
at
normal
operating
tempera-
ture,
but
auxiliary
cooling
fan
does
not
run,
disconnect
connector
from
radiator
temperature
switch
and
make
tests
listed
in
Table
c
.
Table
c
.
Auxiliary
Cooling
Fan
Temperature
Switch
Tests
Wires
jumpered
Test
Test
resuits
conditions
Black/green
(terminal2)
and
Ignition
ON
Fan
runs
on
brown
(terminal
1)
low
speed
Black/gray
(terminal
3)
and
Ignition
ON
Fan
runson
brown
(terminal
I
1)
high
speed
2
.
If
fan
runs
only
when
powered
directly
by
jumpered
connector
and
hot
coolant
is
circulating
through
radia-
tor,
radiator
temperature
switch
is
most
likelyfaulty
.
Use
a
new
sealing
ring
when
replacing
switch
Tightening
Torque
"
Temperature
switch
to
radiator
......
15
Nm
(11
ft-Ib)
3
.
If
auxiliary
fan
does
notrun
when
powered
directly,
check
for
battery
voltage
at
temperature
switch
connec-
tor
(black/green
wire)
with
ignition
on
.
If
battery
voltage
is
not
present,
check
fuses
.
See
610
Electrical
Com-
ponent
Locations
.
RADIATOR
AND
COOLING
SYSTEM
170-
5
~r~nmm
a
00
0
Fig
.
4
.
Auxiliary
radiator
cooling
fan
low
speed
relay
(1)
and
high
speed
relay
(2)
in
power
distribution
box
.
(Relay
locations
may
vary
.)
Auxiliary
Cooling
Fan
Circuit
Fuses
Fig
.
5
.
Auxiliary
radiator
fan
resistor
(arrow)
.
"
Fuse16
.
...................
..
..
...
...
.5
amp
"
Fuse
41
(ex
.
M44
w/man
.
trans)
.
..
.
..
.....
30
amp
"
Fuse
48
(M44
w/man
.
trans
.
only)
..
.
..
.....
40
amp
COOLING
SYSTEM
SERVICE
0013034
4
.
If
no
faults
are
found,
remove
low
speed
relay
and
turn
Coolant,draining
and
filling
ignition
ON
.
See
Fig
.
4
.
1
.
Remove
expansion
tank
cap
.
Set
temperature
controls
"
Check
for
power
at
terminal
30
and
terminal
86
of
relay
to
full
warm
.
socket
.
"
Reinstall
low
speed
relay
and
repeat
testat
high
speed
WARNING
-
relay
socket
.
Fix
any
wiring
faults
found
.
Allow
the
cooling
system
to
cool
before
openlng
or
On
early
productioncars
(up
to
9/92)
:
If
fan
operates
only
on
draining
the
cooling
system
.
high
speed
and
no
electrical
faults
have
been
foundup
to
this
point,
usean
ohmmeter
to
check
that
fan
resistor
is
not
electri-
2
.
Place
3
ra
allo
ug
.
beneath
radiator
drain
plug
and
re-
cally
open
.
Resistor
is
mounted
on
auxiliary
cooling
fan
housing
move
drain
plg
.
See
Fig
.
6
.
behind
front
grille
.
See
Fig
.
5
.
Wiring
diagrams
for
the
radiator
cooling
fan
canbefoundunder
Electrical
Wiring
Diagrams
.
3
.
Place
3-g
pail
beneath
rear
of
engine
blo
.
Loos-
en
and
re
mlon
ove
engine
blockcoolant
drain
plug
k
.
COOLING
SYSTEM
SERVICE