BMW 3 (E46). Manual — part 85

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Remove locking spring clip
retaining fuel pressure regulator.

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Wrap a shop rag around
regulator, then remove regulator
from 3/2 way valve by pulling
straight down.

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Installation is reverse of removal.
Replace sealing O-rings.

Mass air flow (MAF) sensor,
removing and installing

CAUTION!

Be sure the ignition is OFF before
replacing DME system components.

Loosen hose clamp (A) and pull intake
air duct from mass air flow (MAF)
sensor.

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Disconnect electrical harness
connector (B) and unclip fasteners
(C).

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Remove sensor. Inspect protective
screen in sensor housing. Replace
sensor if screen is damaged.

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Inspect air intake ducting for
damage and cracks. Replace
rubber parts as necessary.

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Installation is reverse of removal.

Replace sealing O-ring between
sensor and air filter housing.

Note:

No adjustment to air flow sensor is
possible.

Engine coolant temperature
(ECT) sensor, replacing

The engine coolant temperature (ECT)
sensor is located toward the rear of the
cylinder head below intake runner no.
6. Intake manifold removal is required
to access the ECT sensor.

CAUTION!

Be sure the ignition is OFF before
replacing DME system components.

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Remove intake manifold as
described in

110 Engine

Removal and Installation

.

WARNING!

Due to risk of personal injury, be
sure the engine is cold before
beginning the removal procedure.

Working at rear of cylinder head,
disconnect harness connector (arrow)
from ECT sensor.

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Remove sensor. Catch any
coolant that leaks out with shop
rags.

-

Installation is reverse of removal.

Use a new copper sealing washer
when installing new sensor.

Replace lost coolant.

Tightening torque

Tightening torque

ECT sensor to
cylinder head

13 Nm (10 ft-lb)

Intake air temperature (IAT)
sensor, replacing

The intake air temperature (IAT) sensor
is located at the top center of the intake
manifold. The intake air temperature
sensor functions to adapt or fine tune
the fuel mixture and engine timing
based on varying intake air
temperatures.

Remove housing for microfilter for
interior ventilation.

Remove upper cover and
microfilter.

Open wiring harness loom (A) and
remove wires.

Unfasten screws (B) and remove
lower microfilter housing.

Remove fuel rail cover by prying off
plastic covers (arrows) and removing
nuts.

Remove electrical harness connector
(arrow) from IAT sensor.

CAUTION!

Be sure the ignition is OFF.

-

Depress locking clip on side of
temperature sensor and pull
straight out of intake manifold.

-

Installation is reverse of removal.

Use a new sealing O-ring at base
of sensor and lubricate with
assembly lubricant for ease of
installation.

Throttle assembly, removing
and installing

Some throttle assembly faults will reset
the engine control module (ECM)
adaptation values. BMW's diagnostic
tool (DIS or MoDiC) or aftermarket
equivalent tool is necessary to reset
ECM adaptations after throttle
assembly replacement.

CAUTION!

After replacement of the throttle
valve assembly, and/or on MS 43.0
systems the pedal position sensor,
an adaption procedure must be
performed using the factory scan
tool or equivalent. The vehicle will
not start unless this adaption
procedure is carried out.

Disconnect battery negative (-) cable in
luggage compartment.

CAUTION!

Prior to disconnecting the battery,
read the battery disconnection
cautions given at the front of this
manual on page viii.

Remove complete air filter housing: