
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
.

170-6
RADIATOR
AND
COOLING
SYSTEM
Fig
.
6
.
Radiator
drain
plug
(arrow)
.
WARNING
-
Coolant
is
poisonous
.
Itis
especially
lethal
to
pets
.
Cleanup
spills
immediately
and
rinse
the
area
with
water
.
NOTE
-
The
block
drain
plug
is
located
on
the
exhaust
side
of
the
engine,
near
the
reas
of
the
engine
.
4
.
Reinstall
radiator
and
engine
block
drain
plugsusing
new
sealing
washers
.
Leave
heater
controis
on
full
warm
.
5
.
Using
a
coolantmixture
of
50%
antifreeze
and
50%
dis-
tilled
water,
fill
system
slowly
On
radiator
with
integral
expansion
tank,
bleed
cooling
system
as
described
be-
low
.
NOTE-
"
Tap
water
may
cause
corrosion
of
radiator,
engine
and
coolant
hoses
.
"
Coolant
can
often
be
reused
provided
itis
clean
and
less
than
twoyears
old
.
Do
not
reuse
coolant
when
re-
placing
damaged
engine
parts
.
Contaminated
coolant
may
damage
the
engine
or
cooling
system
.
Tabled
.
Cooling
System
Capacities
Engine
j
Capacity
4-cylinder
1
6
.5
liters
(6.9
qt)
6-cylinder
M50/M52
10
liters
(10
.6
qt)
S50US/S52US
10
.5
liters
(11
.1
qt)
COOLING
SYSTEM
SERVICE
Tightehing
Torques
"
Radiator
drain
plug
to
radiator
...
2-3
Nm
(18-27
in-lb)
"
Engine
block
drain
plug
to
block
.
.
..
25
Nm
(18
ft-Ib)
Cooling
system,
bleeding
(radiator
with
integral
expansion
tank)
NOTE
-
On
radiators
with
a
separate
expansion
tank,
ableed
screw
is
not
provided
.
The
cooling
system
with
sepa-
rate
expansion
tank
is
self
bleeding
via
the
vent
hose
on
the
expansion
tank
.
Air
maybecome
trapped
in
the
system
during
filling
.
Trapped
air
can
prevent
proper
coolant
circulation
.
Whenever
the
coolant
is
drained
and
filled,
the
system
should
be
bled
of
trapped
air
.
1
.
With
engine
cold,
add
coolant
to
expansion
tank
until
level
reaches
COLD
(KALT)
mark
on
tank
.
2
.
Loosen
bleed
screw
on
radiator
expansion
tank
.
See
Fig
.
7
.
0011976
Fig
.
7
.
Cooling
system
bleed
screwon
radiator
(arrow)
.
Note
cold
level
mark
on
expansion
tank
.
3
.
M3
models
:
Loosen
bleed
screw
on
thermostathous-
ing
.
4
.
Set
temperature
controls
in
passenger
compartment
to
fui¡
warm
and
turn
ignition
on
position
(do
not
start
en-
gine)
.

5
.
Slowly
add
coolant
until
it
spills
from
bleed
screws
.
When
coolant
spillíng
from
bleed
screws
is
free
of
air
bubbies,
tighten
screws
.
6
.
Run
engine
until
it
reaches
operatíng
temperature
.
Af-
ter
engine
has
cooled,
recheck
coolant
level
and
top
up
as
necessary
.
CAUTION-
Always
use
genuine
BMW
coolant
or
its
equiva-
lent
to
avoid
the
formation
of
harmful,
clogging
de-
posits
in
the
cooling
system
.
Use
of
other
antifreeze
solutions
may
be
harmful
to
the
cooling
system
.
Tightening
Torque
"
Radiator
bleed
screw
to
thermostat
housing
...
.
.
........
8
Nm
(71
in-lb)
Belt-driven
cooling
fan,
replacing
1
.
Usinga32
mm
wrench
on
fan
clutch
nut,
turn
wrench
quickly
in
a
clockwise
direction
(working
from
front
of
car)
to
loosen
.
Spin
fan
off
pump
.
See
Fig
.
8
.
NOTE-
"
The
radiator
cooling
fan
nut(32
mm
wrench)
has
left-
hand
threads
.
"
The
nut
may
be
difficult
to
loosen
.
Use
a
tool
to
hold
the
coolant
pump
pulleystationary
.
BMW
hasa
spe-
cial
tool
forthis
purpose
(BMW
special
tool
no
.
115
030)
.
2
.
Remove
expansion
rivets
holding
shroud
to
radiator
.
See
Fig
.
9
.
Remove
fan
and
shroud
together
.
NOTE-
Store
the
removed
fan
clutch
assembly
in
an
upright
(installed)
positionto
prevent
lossof
clutch
fluid
.
RADIATOR
AND
COOLING
SYSTEM
170-
7
Fig
.
8
.
Radiatorcooling
fannut
(arrow)
.
Nuthas
left-hand
threads
.
3
.
To
replace
fan
clutch,
remove
fan
mounting
bolts
and
separate
clutch
from
fan
.
Fig
.
9
.
Fan
shroud
retaining
rivet
(arrow)
.
Pryout
center
pin
and
re
4
.
Installation
is
reverse
of
rernoval
.
move
rivet
.
Rivet
design
may
vary
depending
on
model
and
model
year
.
Tightening
Torques
"
Clutchnut
to
coolant
pump
(left-hand
threads)
Wíthout
BMW
tool
no
.
11
5
040
.....
40
Nm
(29
ft-lb)
With
BMW
tool
no
.
11
5
040
.
......
30
Nm
(22
ft-Ib)
"
Fan
to
viscous
clutch
...
.
..
.
......
10
Nm
(89
in-lb)
0013203
COOLING
SYSTEM
SERVICE

Fig
.
13
.
Version
2
auxiliary
fan
mounting
screws
(arrows)
.
Front
bumper
hasbeen
removed
.
4
.
Installation
is
reverse
of
removal
.
Thermostat,
replacing
0013146
The
coolant
thermostat
is
instalied
in
a
housing
at
the
front
of
the
cylinder
head
.
See
Fig
.
14
.
Fig
.
14
.
Coolantthermostat
and
housíng
.
NOTE-
On
M44
engines,
the
thermostat
is
integrated
into
the
thermostat
housíng
.
If
the
thermostat
requiresreplace-
ment,
the
complete
thermostathousing
mustbe
replaced
.
RADIATOR
AND
COOLING
SYSTEM
170-
9
WARNING
-
Allow
the
cooling
system
to
cool
before
opening
ordraining
the
system
.
2
.
Remove
belt-driven
cooling
fan
and
fan
shroudas
de-
scribed
earlier
.
3
.
On
M52/S52US
engines
:
Unclip
wiring
duct
retaining
clips
and
remove
duct
from
above
thermostat
housing
.
Also
remove
engine
front
lifting
bracket
.
4
.
Remove
thermostat
housing
from
front
of
engine
.
See
Fig
.
15
.
Fig
.
15
.
Thermostat
housíng
shown
removed
(6-cylinder
engine)
.
NOTE-
Some
thermostats
have
a
direction
arrowor
venthole
near
the
edge
.
Install
the
thermostat
so
that
either
the
arrow
or
hole
are
at
thetop
.
CAUTION
-
Be
sure
to
reconnect
ground
wire(s)
at
thermostat
housing
mounting
bolt,
where
applicable
.
5
.
Remove
thermostat
.
Note
thermostat
direction
and
ori-
entation
before
removing
.
6
.
Insta¡¡
new
thermostat
and/or
thermostat
housing
using
new
O-ring
and
gasket(s)
as
necessary
.
oo131ss
7
.
Installation
is
reverseof
removal
.
Fill
system
with
cool-
ant
as
described
under
Coolant,draining
and
filling
.
Tightening
Torques
1
.
Drain
radiator
as
described
above
under
Coolant,
"
Thermostat
housing
cover
draining
and
filling
.
to
housing
orcoolant
pump
..
..
....
10
Nm
(89
in-lb)
"
Engine
lifting
bracket
bolt
to
thermostat
housing
(M52/S52US
engine)(M8)
....
..
...
22
Nm
(17
ft-Ib)
COOLING
SYSTEM
SERVICE

170-10
RADIATOR
AND
COOLING
SYSTEM
Coolant
pump,
replacing
The
engine
coolant
pump
is
mounted
in
the
frontof
the
en-
gine
on
the
timing
cover
.
See
Fig
.
16
.
Fig
.
16
.
Coolant
pump
mounted
on
timing
cover
.
NOTE-
Onlyreplacement
coolant
pumps
with
metal
¡mpellers
should
be
installed
.
Pumps
with
plastic
impellers
should
not
be
used
.
1.
Drain
cooling
system
as
described
earlier
.
0013197
WARNING
-
Allow
cool¡ng
system
to
cool
before
open¡ngor
drain¡ng
system
.
2
.
Remove
primary
cooling
fan
shroud
and
cooling
fan
(belt-driven
or
electric)
as
described
earlier
.
Fig
.
17
.
Engine
drive
belt
tensioner
being
released
on
M44
engine
.
Pry
off
tensioner
cover
and
then
lever
tensioner
in
counterciock-
wise
direction
(as
facing
engine)
and
slip
belt
off
pulleys
.
Fig
.
18
.
Drive
belt
tensioner
being
released
on
M52
engine
.
Pry
off
3
.
Disconnect
hoses
from
thermostat
housing
.
Unbolt
tensioner
cover
and
then
lever
tensioner
clockwise
(as
facing
thermostat
housing
from
front
of
cylinder
head
.
engine)torelease
belt
tension
.
4
.
Remove
coolant
pump
drive
belt
.
See
Fig
.
17
or
Fig
.
18
.
NOTE-
-
Mark
direction
of
drive
belt
rotation
if
reusing
belt
.
"
The
6-cylinder
coolant
pump
¡s
mounted
on
studs
and
retained
by
nuts
.
"
Severa¡
drive
belt
and
tensioner
configurations
havebeenused
in
E36
models
.
Refer
to
020
Maintenance
Program
and
640
Heating
and
Air
Conditioning
.
5
.
Remove
coolant
pump
pulley
from
pump
.
6
.
Remove
mounting
fasteners
from
pump
.
COOLING
SYSTEM
SERVICE
NOTE-
"
The
4-cylinder
coolant
pump
¡s
mounted
us¡ng
two
dif-
terent
length
bolts
.
Note
where
thelonger
bolt
fits
dur-
ing
disassembly
.
0011989
7
.
Insert
twoscrews
(M6)
in
tapped
bores
and
tighten
uni-
formly
until
pump
is
free
from
timing
chain
cover
.
See
Fig
.
19
.

Fig
.
19
.
Coolant
pump
being
removed
.
Thread
two
M6
bolts
(arrows)
in
evenly
to
withdraw
pump
.
(Thermostat
and
hoseshavebeen
removed
tor
visual
access
.)
8
.
Installation
is
reverse
of
removal
.
"
Be
sure
to
replace
O-ring
and
gaskets
.
"
Coat
O-ring
with
lubricant
during
installation
.
Tightening
Torque
"
Coolant
pump
to
timing
chaincover
M6
...
.
...................
..
.
.
10
Nm
(89
in-lb)
M8
.
..
.
....................
.
.
.
22
Nm
(17
ft-Ib)
"
Coolant
pump
pulley
to
coolant
pump
.................
10
Nm
(89
in-lb)
RADIATOR
SERVICE
Radiator,
removing
and
installing
1
.
Drain
radiator
as
described
earlier
.
WARNING
-
Allow
cooling
system
to
cool
before
opening
ordraining
system
.
2
.
Remove
primary
cooling
fan
(belt-driven
or
electric)
as
described
earlier
.
3
.
Disconnect
coolingfan
and
leve¡
sensor
harness
con-
nectors
from
bottom
of
radiator,
where
applicable
4
.
Disconnect
harness
connector
from
auxiliary
fandual
temperature
switch
.
See
Fig
.
20
.
5
.
Disconnect
all
coolant
hoses
from
radiator
.
RADIATOR
AND
COOLING
SYSTEM
170-11
0012500
Fig
.
20
.
Cooling
fan
dual
temperatura
switch
(arrow)
on
right
sido
of
radiator
.
6
.
Where
applicable,
disconnectautomatic
transmission
fluid
(ATF)
cooler
lines
from
radiator
.
See
Fig
.
21
.
Fig
.
21
.
Automatic
transmission
fluid
(ATF)
linos
at
radiator
.
7
.
Carefully
pryout
radiator
retaining
clips
from
top
of
ra-
diator
.
See
Fig
.
22
.
8
.
Pul¡
radiator
up
and
out
of
car
.
NOTE-
The
radiator
rests
ontwo
rubber
mounts
.
Check
that
the
mounts
do
not
stick
to
the
bottomof
the
radiator
.
RADIATOR
SERVICE

EKE
Power
1992-
VIO
FROMIGNITION
U
VIO
FROM
IGNITI
ON
SWITCH
SWITCH
2S
(DIAGRAM3OF7)
31
(DIAGRAM3OF7)
I
-
______________-__________--
4
-_____________________I_-FRONT
POWER
O
3
3
3
3
i
14
8
8
B
18
7
26
-
4
4
I
i
I
I
i
-F-
I
i
I
-
,
I
,
I
I
F-,
ON
-BOARD
CHECKCONTROL
WIPER
WIPER
MOTOR
INSTRUMENT
BRAKELIGHT
CRUISE
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MIRROR
LIGHT
HIGH
BEAM
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THROTTLE
SERVOTRONIC
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CONTROL
SWITCH
LIGHT
LIGHTSWITCH
TRANSMISSION
SWITCH
FLAP
CONTROL
CLUSTER
SWITCH
RELAY
RANGESWITCH
HEATER
MODULE
(1996)(1996)
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THERMOSTAT
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REAR
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AEC
ABSSLIP
ASS
RELAY
CLIMATE
VALVE
SWITCH
CLUSTER
DEFOGGER
FUNCTION
RELAY
MODULE
(ABS)
SWITCH
SWITCH
CONTROLCONTROL
ASSEMBLY
RELAYCLOCK
(1996)
MODULEMODULE
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