BMW 3 (E46). Manual — part 288

640-5

Heater Components

The heater valve is located in the left
side of the engine compartment,
attached to the left strut tower. The
solenoid operated valve controls
coolant flow through the heater core.

The IHKA housing, located underneath
the center of the dashboard, houses
the heater core, the A/C evaporator, the
heating and A/C blower and associated
sensors and air distribution motors.

CAUTION!

Removal of either the heater core or
the IHKA housing involves
dashboard removal. Before starting
work, disconnect the battery
negative (-) cable in the trunk. Be
sure to read the battery
disconnection cautions on page viii
and the airbag warnings in

721

Airbag System (SRS)

.

Heater valve, replacing

-

Drain engine coolant. See

170

Radiator and Cooling System

.

WARNING!

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

Disconnect hoses (A) and electrical
harness connector (B) at heater valve
on left inner fender.

-

Carefully pull heater valve out of
rubber mounting and pull up and
out of engine compartment.

-

Installation is reverse of removal.

Inspect hoses and rubber mounts.
Replace as necessary.

Use new hose clamps.

Tightening torque

Coolant hose
clamp
32 - 48 mm
(2 1/4 - 4 in.)

2.5 Nm (22 in-lb)

Heater core, replacing

Remove housing for interior ventilation
microfilter.

Remove upper cover and
microfilter.

Open wiring harness loom (A) and
remove wires.

Unfasten screws (B) and remove
lower housing.

-

Remove center console and
dashboard. See

513 Interior

Trim

.

-

Drain engine coolant. See

170

Radiator and Cooling System

.

WARNING!

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

Working at rear engine compartment
bulkhead, loosen hose clamps
(arrows) and detach heater hoses.

-

Blow out excess coolant from
heater core using compressed air
at coolant lines.

-

Release right air duct from IHKA
housing.

Working inside passenger
compartment at IHKA housing:

Detach wiring harness (A) from
housing.

Remove heater core temperature
sensor (B) by pulling straight out.

Remove retaining clips (C) from
housing cover.

Lift off front of cover, then unhook
tabs from housing at rear.

Remove coolant pipe retaining clamps
mounting screws (arrows).

To remove heater core from IHKA
housing:

Remove coolant pipe retainers

(arrows) to detach pipes.

Tilt heater core to remove from
housing.

-

Installation is reverse of removal.

Fit lugs in back of housing cover
in heater housing slots.

Use new sealing O-rings and coat
with anti-seize agent.

Fill and bleed cooling system.
See

170 Radiator and Cooling

System

.

CAUTION!

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

Tightening torque

Coolant hose
clamp
32 - 48 mm
(2 1/4- 4 in.)

2.5 Nm (22 in-lb)

IHKA housing, removing and
installing

CAUTION!

Removing the IHKA housing
requires evacuating the A/C
system. DO NOT attempt this
procedure without proper tools
and training.

Any person who services a