BMW M3 1998 E36 Workshop Manual

Fig
.
12
.
Mounting
bolt
for
A/C
refrigerant
line
flange
(arrow)
.

001Suu7

Fig
.
13
.
A/
C
control
module
(A)
behind
center
console
.
Arrows
pointto
electrical
harness
connectors
to
be
disconnected
.

CAUTION
-

Replace
heater
and
AIC
flange
O-rings
and
tight-

en
fasteners
to
specified
torques
.

0012644

HEATING
AND
AIR
CONDITIONING



640-5

Fig
.
14
.
Heating
and
ventilation
ducts
on
left
side
of
heater
box
(arrows)
.
Right
side
ducts
are
similar
.

Fig
.
15
.
Heater
box
retaining
bracket
in
center
console
(arrow)
.

0012645

10
.
Unclip
andremove
heating
and
ventilation
ducts
on



Tightening
Torques

sides
of
heater
box
.
See
Fig
.
14
.



"
A/C
refrigerant
lines
flange

to
bulkhead
..............
.
..
..
.
3
.5
Nm
(31
in-lb)

11
.
Remove
heater
box
retaining
bracket
on
center
tunnel



"
Water
hose
flange
to
bulkhead

and
remove
heater
box
.
See
Fig
.
15
.



(M6
nut)
................
.
...
..
3
.5
Nm
(31
in-lb)

"
Heater
box
retaining
bracket

12
.
Installation
is
reverse
of
removal
.
Evacuate
and
re-



to
tunnel
................
.
..
..
.
4
.5
Nm
(40
in-lb)

charge
A/C
system
using
specialized
equipment
.
Fill

and
bleed
cooling
system
.
See
170
Radiator
and

Cooling
System
.

HEATER
AND
CONTROLS

640-6



HEATING
AND
AIRCONDITIONING

Heater
core,replacing

1.
Drain
engíne
coolant
.
See170
Radiator
and
Cooling

System
.

WARNING
-

Allow
the
cooling
system
to
cool
before
opening
or
drainíng
the
cooling
system
.

2
.
Remove
center
console
.
See
513
Interior
Trim
.

3
.
Remove
Multi-Information
Display
(MID)
module
.
See

620
Instruments
.

4
.
Remove
lower
dash
panel
and
knee
bolster
on
driver

side
.
See
513
Interior
Trim
.

Fig
.
17
.
Wire
harness
retaining
clips
and
wire
ties
at
heater
box
cover
5
.
Working
under
driver
side
of
dash,
remove
coolant



(arrows)
.
flange
from
heater
core
.
See
Fig
.
16
.

0012651

Fig
.
16
.
Bolts
at
3-way
coolant
flange
under
driver's
side
of
dash
(ar-
rows)
.

NOTE-

Residual
coolant
in
heater
core
will
spill
.
Protect
thecarpet
.

6
.
Working
at
front
of
driveshaft
tunnel,
unclip
wire
har-

nesses
and
move
to
one
side
in
front
of
heater
box
.
See
Fig
.
17
.

7
.
Remove
heatercore
temperature
sensorsas
described

later
in
this
repair
group
.

8
.
Remove
front
heater
box
cover
.
See
Fig
.
18
.

9
.
On
right
side
of
heater
box,
unclip
heater
air
duct
actu-
ating
lever
.
Remove
cross-rod
(with
flaps)
from
frontof
heater
core
.
See
Fig
.
19
.

HEATER
AND
CONTROLS

0012662

Fig
.
18
.
Screws
retaining
front
heater
box
cover
(shown
removed)
to
heater
box
(arrows)
.

0012661
Fig
.
19
.
Pry
heater
flap
actuating
lever
in
direction
A
.
Pull
offair
flap
cross-rod
in
direction
B
.

10
.
Pul¡
heater
core
up
and
backward,
away
from
heater
box
.
If
necessary,
remove
left
and
right
reinforcing
bracket
bolts
.
See
Fig
.
20
.

CAUTION-

Replace
coolant
flange
O-rings
and
tighten
fas-
teners
to
specified
torques
.

Tightening
Torques

1
.
Remove
center
console
.
See
513
Interior
trim
.

0012660

Fig
.
20
.
PA
heater
core
upand
towardback
of
car
.
Lower
mounting
bolts
for
steering
column
brace
and
glove
compartment
sup-
port
frame
may
have
to
be
removed
(arrows)
.

11
.
Installation
is
reverse
of
removal
.
Fill
and
bleed
cooling

system
.
See
170
Radiator
and
Cooling
System
.

"
Coolant
flange
to
heater
core
.
..
....
3
Nm
(27
in-lb)



Heater
andA/C
Control
Head

Heatercore
temperature
sensor,
replacing

The
automatic
heating
and
air
conditioning
systemuses

severa¡
sensors
to
control
interior
air
temperature
.
Use
the
fol-

lowing
procedure
and
the
data
in
Table
b
to
pinpoint
problems

with
theheater
core
sensors
.

2
.
Remove
Multi-Information
Display
(MID)
module
.
See

6201nstruments
.

HEATING
AND
AIR
CONDITIONING



640-7

0012648

Fig
.
21
.
Remove
heatercore
temperaturesensors
in
direction
shown
(arrow)
.

Table
b
.
Heater
CoreTemperatureSensor
Test

Values

Test
temperature



Resistance

4°F
(-20°C)



84
.39
-
109
.61
k
ohms

14
°
F
(-10°C)



48
.58
-
62
.09
k
ohms

32°F
(0°C)



28
.89
-
36
.40
k
ohms

68°F
(20°C)



11
.13
-
13
.83
k
ohms

140°F
(60°C)



2
.19
-
2
.78
k
ohms

212°F
(100°C)



0
.58
-
0
.77
k
ohms

Two
types
of
heater
and
aír
conditioning
control
heads
viere
installed
in
E36
cars
.
Early
models
have
control
heads
with
four
rotary
knobs
and
a
separate
control
module
.
A
flexible

shaft,
clipped
to
the
right
sideof
the
control
head,
controls
the
heater
flaps
.

Later
model
E36
cars,
starting
in
approximately
mid-1995,

have
digital
display
control
heads
with
buttons
.
The
A/C
con-
trol
module
is
integrated
with
the
digital
control
head
.

Heater
and
A/C
control
head,

removing
and
installing
(rotary-knob)

3
.
Pul¡
temperature
sensors
from
heater
box
and
discon-



1
.
Remove
Multi-Information
Display
(MID)
module
from

nect
harness
connectors
.
See
Fig
.
21
.



center
of
dash
.
See
620
Instruments
.

4
.
Installation
is
reverse
of
removal
.



2
.
Pul¡
off
outer
rotary
knobs
from
A/C
control
head
.
Re-

move
two
screwsonknob
bezels
.
Remove
control
pan-

el
face
plate
by
prying
it
off
control
head
gently
.
See
Fig
.

22
.

3
.
Carefully
push
control
head
back
into
dash
and
down-

ward
through
MID
opening
.
See
Fig
.
23
.

HEATER
AND
CONTROLS

640-8



HEATING
AND
AIR
CONDITIONING

0012649

Fig
.
22
.
A/
C
control
head
faceplate
screwson
rotary
knob
version
(ar-
rows)
.
Once
screws
are
removed,
faceplate
must
be
un-
clipped
from
control
head
.

Fig
.
23
.
Push
control
panel
out
ofcenter
console
.

4
.
Remove
harness
connectors
.
Unfasten
heater
duct
control
flex-shaft
on
right
side
of
control
head
by
squeezing
retaining
tab
.
PA
shaftout
of
coupling
in
control
head
and
remove
head
.

5
.
Installation
is
reverseof
removal
.

HEATER
AND
CONTROLS

0012650

Heater
and
A/C
control
head,

removing
and
installing(digital-display)

1
.
Remove
Multi-Information
Display
(MID)
module
from

center
of
dash
.
See
620
Instruments
.

2
.
Reach
into
dash
through
MID
opening
and
push
A/C

control
head
outwards
.

3
.
Disconnect
harness
connector
and
remove
control

head
.

4
.
Installation
is
reverse
of
removal

Heater
andA/C
control
module,

removing
and
installing
(rotary-knob)

1
.
Remove
Multi-Information
Display
(MID)
module
from

center
of
dash
.
See
620
Instruments
.

2
.
Remove
center
console
.
See
513
Interior
Trim
.

3
.
Disconnect
wiring
harness
connectors
to
A/C
control

module
in
center
console
and
removemodule
.
See
Fig
.

24
.

0013007
Fig
.
24
.
A/
C
control
module
(A)
in
center
console
.
Arrows
point
to
electrical
harness
connectors
at
A/Cmodule
.

Heater
and
A/C
control
module,

removing
and
installing(digital-display)

TheA/C
control
module
for
cars
with
the
digital
display
is
mounted
on
the
back
of
the
control
head
.
See
Fig
.
25
.

1
.
Remove
control
head
as
described
earlier
and
place
onan
anti-static
mat
.

Sensor

fan

Fig
.
25
.
Digital
display
A/C
control
head
components
.

2
.
Unscrew
left
and
right
screws
retaining
control
head
to
control
module
.
Press
retaining
clips
and
release
front
plate
from
control
head
.
Remove
A/C
control
module
from
control
head
housing
.

Sensor
fan
for
interior
temperature,

repiacing

A
small
electricfan,installed
in
the
A/C
control
head,
draws
cabin
air
past
the
climate
control
temperature
sensor
.

1.
Remove
A/C
control
head
as
described
earlier
.

2
.
Rotary-knob
control
head
:
Disconnect
electrical
con-
nector
from
top
of
control
head
housing
.
Pry
open
plas-

tic
housing
and
remove
sensor
fan
.
See
Fig
.
26
.

0013181

Fig
.
26
.
Sensor
fan
(A)
and
harness
(B)
in
back
of
A/C
control
head
(rotary-knob
control
head
shown)
.

3
.
Digital
display
models
:
Disconnect
electrical
harness

connector
from
control
head
housing
.
Remove
screws

holding
sensor
fan
to
bottom
of
control
moduleand
re-
move
.
Refer
to
Fig
.
25
.

4
.
Installation
is
reverse
of
removal
.

HEATING
AND
AIR
CONDITIONING



640-
9

Heater
and
A/C
Air
Distribution
Motors

The
recirculation,
fresh
air
and
othervent-duct
flaps
are
controlled
electrically
via
a
series
of
air
distribution
actuating
motors
.
Cars
with
the
rotary-knob
control
head
use
three
elec-
tromechanical
motors,
each
held
in
place
via
a
small
plastic
clip
.
See
Fig
.
27
.

Rightside
of
heater
box
l

Fig
.
27
.
Location
of
early
production
air
distribution
motors
(arrows)
.

Later
systems
(with
the
digital
display
control
head)
use
five
distribution
motors,
four
of
which
are
digítally
controlled
.
See
Fig
.
28
.

HEATER
AND
CONTROLS

640-10



HEATING
AND
AIR
CONDITIONING

i

El
Radio

Antenna

Rear



.
,



si,-
Left
side



I
d

1
.
Rear
vents
2
.
Fresh
air
3
.
Face-level
vents
4
.
Recirculation
5
.
Footwell
vents
0013017

Fig
.
28
.
Location
oflate
production
air
distribution
motors
in
heater
box(shown
in
rear,
side
and
top
views)
.

Heater
andA/C
air
distribution
motor,

replacing
(rotary-knob)

1
.
Toaccess
left
side
motors
(dash
vent
mixing
or
recircu-

lation
flap),
remove
lower
dash
panel
and
knee
bolster

on
driver
side
.
See
513
Interior
Trim
.

2
.
To
access
right
side
motor
(fresh
air
flap),
remove
glove

compartment
.
See513
Interior
Trim
.

3
.
Each
motor
can
be
removed
after
its
electrical
wiring

harness
connector
has
been
removed
.
Squeeze
plastic

clip
to
release
motor
.
See
Fig
.
29
.

Fig
.
29
.
A/
C
air
distribution
motor
plastic
retaíning
clip
(arrow)
.
Re-
lease
clip
and
tilt
motor
out
of
housing
.

Rear
Window
Defogger

0011877

The
rear
window
defogger
switch
is
integrated
with
the
heating
andA/C
control
head
.

HEATER
AND
CONTROLS

Fig
.
30
.
Wiring
diagram
of
rear
window
defogger
and
radio
antenna
.

Rear
Window
Blower
(Convertible
Models)

A
blower
fan,
fitted
into
the
rear
seatback,
defogs
therear

window
.
It
will
only
operate
with
the
engine
nunning
and
the

top
raised
.
A
microswitch
behindthe
rear
seats
provides
the

signal
that
thetop
is
raised
.

To
access
the
blower
fan
motor,
it
is
necessary
to
remove

four
screwsfrom
the
center
seat
back
.
Remove
the
wiring
har-

ness
connector
and
motor
mounting
boits,
then
remove
motor

by
pulling
it
down
and
forward
.
See
Fig
.
31
.

ri

Suppressor
filter

1
0013005

Fig
.
31
.
Rear
window
blower
in
center
of
rear
seat
back
(arrow)
.

The
electric
rear
window
defogger
is
integrated
with
the
ra-

dio
antenna
.
See
Fig
.
30
.



y



/f



0013014

To
access
the
rear
window
blower
relay,
remove
the
glove
compariment
.
See
Fig
.
32
.

Fig
.
32
.
Rear
window
blower
relay
located
in
frontof
glove
compart-
ment
(arrow)
.

AIR
CONDITIONING

Thissection
covers
removal
and
installation
of
air
condition-

ing
refrigerant
components
.
A/C
testing
and
diagnosis,
refrig-

erantdischarge,
evacuatíon
and
recharge
are
not
covered

here
.

The
subassemblies
and
lines
of
the
air
conditionerare
filled

with
either
refrigerant
R12
(1992
cars)
or
R-134a
(1993
and

later
cars)
.
The
major
components
of
the
A/Csystem
are

shown
in
Fig
.
33
.

A/CSystem
Warnings
and
Cautions

WARNING
-

"
Always
be
careful
that
refrigerant
does
not
come
in
contact
with
your
skin
.
Always
wearhand
andeye
protection
(gloves
and
goggles)
when
work-

ing
around
the
AIC
system
.
If
refrigerant
does
come
in
contact
with
your
skin
oreyes
:
-Do
not
rub
skin
oreyes
;

-Immediately
flush
skin
oreyes
withcool
water
for
15
minutes
;
-Rush
to
a
doctor
orhospital
;
-Do
not
attempt
to
treat
yourself
.

"
Work
in
a
wefl
ventilated
area
.
Avoid
breathing
re-
frigerant
vapors
.
Exposure
may
irrítate
eyes,

nose,
and
throat
.
Switch
on
exhaustlventilation
systems
when
working
on
the
refrigerant
system
.

"
Do
not
expose
any
component
of
the
AIC
system
to
high
temperatures
(Above
80°Cl176°F)or

open
flames
.
Excessive
heat
will
cause
a
pres-

sureincrease
whichcould
burst
the
system
.

HEATING
AND
AIR
CONDITIONING



640-
1
1

0013015

WARNING
-

"
Keep
refrigerant
away
from
open
llames
.
Poison-
ous
gas
will
be
produced
if
it
bums
.
Do
not
smoke
near
refrigerant
gases
for
the
same
reason
.

"
The
AICsystem
is
filled
with
refrigerant
gas
which
is
under
pressure
.
Pressurized
refrigerant
in
the
presenceof
oxygen
may
forma
combusti-
ble
mixture
.
Never
introduce
compressed
air
finto
any
refrigerant
container
(full
or
empty),
capped
off
AIC
component,
or
piece
of
service
equip-
ment
.

"
Refrígerant
gases
are
heavier
than
air,
displace
oxygen
and
may
cause
suffocation
in
areas
of
poor
círculation,
for
example
under
a
car
.
Switch
on
exhaustlventilation
systems
when
working
on
the
refrigerant
system
.

"
State
and
local
governments
may
have
additional
requirements
regarding
air
conditioning
servic-
ing
.
Alwayscomply
with
state
and
local
laws
.

"
Electric
welding
near
refrigerant
hoses
causes
R-134a
to
decompose
.
Discharge
system
before
welding
.

CA
UTION
-

-As
of
January
1,
1992,
any
person
who
services
a
motor
vehicle
air
conditioner
must,
by
law,
be
properly
trained
and
certified,
and
use
approved
refrigerant
recycling
equipment
.
Technicians
must
complete
an
EPA-approved
recycling
course
to
be
certified
.

"
It
is
recommended
that
al¡
system
refrigerant
AIC
refrigerant
be
left
to
an
authorized
BMW
dealer
or
other
qualified
AIC
service
facility
.

"
Do
not
top
off
a
partially
charged
refrigerant
sys-
tem
.
Dischargesystem,evacuate
and
then
re-
charge
system
.

"
R-134a
and
R-12
refrigerants
and
refrigerant
oils
and
system
components,
including
hoses
and
sealing
O-rings,
are
NOT
compatible
.
Compo-
nent
damage
andlor
system
contamination
will

result
.

"
The
mixture
of
refrigerant
oil
(PAG
oil)
and
refrig-
erant
R-134a
attacks
some
metals
and
alloys
(for
example,copper)
and
breaks
down
certain
hose
materials
.
Use
only
hoses
and
lines
that
are
iden-
tified
with
a
green
mark
(stripe)
or
the
lettering
R-
134a"
.

"
Immediately
plug
open
connections
on
AIC
com-
ponents
to
prevent
dirt
and
moisture
contamina-
tion
.

"
Do
not
steam
clean
condensers
or
evaporators
.

Use
only
cold
water
or
compressed
air
.

AIR
CONDITIONING

640-12



HEATING
AND
AIR
CONDITIONING

A/C
Compressor,
replacing

1
.
Followingmanufacturer's
instructions,
connectanap-

proved
refrigerant
recovery/recycling/recharging
unit
to

A/C
system
and
discharge
system
.

WARNING
-

Do
notdischarge%harge
the
AIC
system
without
proper
equipment
and
training
.
Damage
to
the
vehi-
cle
and
personal
injury
may
result
.

2
.
Remove
splash
shield
fromunder
engine
.

3
.
Mark
A/C
drive
belt
with
direction
ofrotation
.
Remove

A/C
belt
tensioner
trim
cap
.
See
Fig
.
34
.

0011988
Fig
.
34
.
To
access
tensioner
retaining
bolt,
remove
trim
cap
from
drive-belt
tensioner
.

Fig
.
33
.
A/
C
components
.
Arrows
indicatedirection
of
refrigerant
flow
.

AIR
CONDITIONING

4
.
On
4-cylinder
engines
:
Loosen
A/C
belt
tensioner
bolt

under
trim
cap,
then
remove
belt
from
A/C
compressor
.

See
Fig
.
35
.

~=1

A/C
compressor



A



0013019

Fig
.
35
.
4-cylinder
engines
:
Loosen
retaining
bolt
A
on
tensionerto
re-
lease
drive-belt
tension
.
To
increase
tension,
rotate
pulley
in
direction
of
arrow,
then
tighten
bolt
A
.

5
.
On
6-cylinder
engines
:
Release
tension
on
A/C
belt
by

turning
tensioner
pulley
clockwíse
(againstspring
ten-
sion)
.
See
Fig
.
36
.

NOTE
-

Detailed
instructions
for
drive-belt
removal
and
installa-tion
can
be
found
in
020
Maintenance
Program
.

Fig
.
36
.
6-cylinder
engine
belt
diagram
:
To
remove
A/C
belt,
lever
ten-
sioner
(A)
in
clockwise
direction
using
long-handled
wrench
or
breaker-bar
.

6
.
Disconnect
electrical
harness
connector
from
com-
pressor
.

7
.
Remove
A/C
pressure
hose
and
suction
hose
flange



10
.
Before
recharging,
evacuate
system
for
at
least
30
min
.
bolts
from
compressor
.
Plug
hoses
immediately
See



Recharge
system
following
equipment
manufacturer's

Fig
.
37
.



instructions
.
See
Table
d
.
A/C
System
Refrigerant

Capacities
.

0011879

Fig
.
37
.
A/
C
compressor
pressure
hose
(A)
and
suction
hose
(B)
.
(6-
cylinder
engine
shown
.
4-cylinder
engine
is
similar
.)

HEATING
AND
AIR
CONDITIONING



640-
1
3

Fig
.
38
.
A/
C
compressor
mounting
boits
(arrows)
.

9
.
Installation
is
reverseof
removal
.

CAUTION
-

"
Always
replaceO-rings
when
reconnecting
re-
frigerantfines
.

"
When
installlng
a
new
compressor
always
re-
place
receiverldrier
unit
.

Tightening
Torques

"
A/C
compressor
to
engine
block
....
22
Nm
(17
ft-Ib)
"
A/C
line
flange
to
A/C
compressor
5/8
in
.
fine
.
......
.....
....
.
.....
20
Nm
(15
ft-Ib)

3/4
in
.
fine
.......
.....
..........
39
Nm
(29
ft-Ib)

7/8
in
.
fine
...
....
.....
..........
42
Nm
(31
ft-Ib)

11/16
in
.
fine
.....
..
..
..
...
.
.....
48
Nm
(35
ft-Ib)

A/C
Compressor
Clutch

The
compressor
clutch
can
be
replaced
without
disturbing

thesealed
refrigerant
system,
although
clearances
in
the
six-

cylinder
cars
may
be
very
tight
.
Detach
the
compressor
from

the
compressor
bracket
togain
extra
clearance
.

8
.
Remove
compressor
mounting
boits
.
See
Fig
.
38
.
Re-



Typical
A/C
compressor
and
clutch
is
shown
in
Fig
.
39
.
move
compressor
by
pulling
downward
from
under-

neath
car
.



Remove
driveplate
and
pulley
to
access
clutch
magnetic

winding
.
See
Fig
.
40
.

AIR
CONDITIONING

640-14



HEATING
AND
AIR
CONDITIONING

7
Fig
.
39
.
A/
C
compressorand
clutch
components
.

8
00871208

1.
Clutch
plate
retaining
bolt



5
.
A/C
compressor
pulley
2
.
Clutch
plate



6
.
Clutch
retaining
circlip
3
.
Pulley
retaining
circlip



7
.
Clutch
(magnetic
winding)
4
.
Clutch
bearing



8
.
Compressor

00870082

Fig
.
40
.
A/
C
compressor
driveplate
canbe
held
stationary
with
strap
toolto
allow
removal
of
retaining
bolt
.

NOTE-

BMWs
are
equipped
with
compressors
from
various
manufacturers
.
Special
tools
may
be
required
tore-
move
driveplate
orpulley
.

AIR
CONDITIONING

Tightening
Torque

"
Compressor
clutch
bolt

to
compressor
shaft
.....
.
....
..
.
.
20
Nm
(15
ft-Ib)

A/C
condenser,
replacing

1
.
Following
manufacturer's
instructions,
connect
an
ap-

proved
refrigerant
recovery/recycling/recharging
unitto

A/Csystemand
discharge
system
.

WARNING
-

Do
not
dischargelcharge
the
AIC
system
without
proper
equipment
and
training
.
Damage
to
the
vehi-
cle
and
personal
injury
may
result
.

2
.
Remove
front
bumper
and
radiator
grilles
.
See510
Ex-

terior
Trim,
Bumpers
.

3
.
Remove
auxiliary
electric
radiator
fan
.
See
170
Cool-
ing
System
.

4
.
DetachA/C
lines
from
lower
right
corner
of
condenser
.

Plug
lines
immediately
.
See
Fig
.
41
.

Fig
.
41
.
A/
C
flange
bolts
at
condenser
(arrows)
.

5
.
Remove
condenser
mounting
bolts
from
frontradiator

support
.
See
Fig
.
42
.

6
.
Lift
up
condenser
to
disengage
from
lower
mounts
and

remove
from
below
.

7
.
Installation
is
reverse
of
removal
.

CA
UTION-

"
Always
replace
O-rings
when
reconnecting
re-
frigerant
fines
.

"
When
installing
a
new
condenser
always
replace
receiverldrier
unit
.