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11 3-9
Cylinder Head Removal and Installation
< Remove left and right interior ventilation ducts (left shown):
Release ventilation filter cover latch (A) and remove cover.
Release plastic locking tab
(6) or release locking tabs on
top of duct (later models).
Rotate duct counterclockwise to unlock from bulkhead and
remove (arrow).
Disconnect electrical connector from hood switch
(C).
Release spring lock (D).
Slide filter housing away from inner fender to remove.
Removal of right side ventilation duct is similar.
Remove rear bulkhead panel: Remove rubber sealing
gasket (arrow).
0 Remove 3 mounting clips (A).
Remove
4 retaining screws (6).
Lift out panel.
< Remove complete air filter housing:
Loosen
intake duct hose clamp (A) at throttle assembly.
Loosen clamp and remove idle control hose from
~ntake
duct (6) and disconnect Idle speed control valve electr~cal
harness connector.
Disconnect
electr~cal harness connector (C) from mass alr
flow sensor.
Remove air filter housing mounting screw (D).
Disconnect vent tube
(E).
Loosen air intake duct clamp (F).
Carefully lift air filter housing out of engine bay.
4 Remove positive battery cable and intake manifold cover:
Remove protective cover from positive (+)jumper post (A).
Loosen and remove battery lead mounting nut.
Remove battery lead and push down through intake mani-
fold.
Remove trim caps (arrows) from fuel injector cover.
Remove cover hold down fasteners and lift off cover.
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1 13-22
Cylinder Head Removal and Installation
CYLINDER HEAD REMOVAL AND
~NSTALLATION (M52 TU AND N154
ENGINES)
WARNING -
Due to risk ofpersonal injur)c be sure the engine is cold be-
fore
beqinning the removal procedure.
Cylinder head removal and installation is a time consuming
repair procedure requiring multiple special service tools.
Read the entire procedure before beginning the repair.
This topic includes the following procedures:
* Cylinder head, removing, M52 TU and M54 engines
Cylinder head, installing,
M52 TU and M54 engines
Cylinder head, removing,
M52 TU and M54 engines
Allow engine to cool before beginning this procedure.
- Disconnect negative (-) cable from battery.
CAUTION-
Prior to disconnecting the battery, read the battery discon-
nection cautions in
001 General Cautions and Warnings.
4 Remove left and right interior ventilation ducts (left side
shown):
Release ventilation filter cover latch
(A) and remove cover.
Release plastic locking tab
(6) or release locking tabs on
top of duct (later models).
= Turn duct counterclocltwise to unlock from bullthead and
remove (arrow).
Disconnect electrical harness from hood switch (C).
Release spring lock fastener
(D).
- Slide filter housing away from inner fender to remove.
Removal of right side ventilation
dud
Remove rear bulkhead panel:
Lift off rubber sealing
gasket (arrow)
- Remove 3 mounting clips (A).
Remove 4 retaining screws (6).
Lift off panel.
: is similar
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Cylinder Head Removal and Installation /
4 Remove top engine cover by releasing quick release fasten-
ers (arrows) by pressing down.
NOTE-
Earlier models may have an engine cover with pry off caps
and fasteners
In place of quick release fasteners.
4 Remove left and right interior ventilation ducts (left side
shown):
- Release locking tabs (A) or locking strap (early models, not
shown).
Release spring lock (B).
* Rotate duct inward (arrow) to remove.
Disconnect electrical harness from hood light switch (C).
Release locking clip and remove ventilation housing cover
(D).
Lift out housing from inner fender.
- Removal of right side ventilation housing is similar.
4 Air filter housing assembly, removing:
Disconnect electrical harness connectors from mass air
flow sensor (A) and temperature sensor (B).
Loosen hose clamp (C).
Remove filter housing mounting fastener (arrow) and re-
move filter housing with mass air flow sensor.
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Cylinder Head and valvetrain1
Hydraulic lifters, checking and replacing
Self-adjusting hydraulic lifters (A) keep the valve clearances
within a limited working range. Hydraulic lifters are sealed
units and require no maintenance. Section view of camshaft
(6) and valve with conical valve spring (C) shown.
Under some circumstances, such as a cold start, the cam fol-
lowers may emit noise. Hydraulic lifter noise is usually a
high-
pitched tapping or chattering noise. In most instances, this is
considered normal as long as the noise goes away in a few
minutes (maximum
20 minutes). If the noise does not go
away, either the lifter is faulty or the oil pressure to the lifter is
low. Hydraulic lifter replacement requires that the camshaft
first be removed.
NOTE-
Before checking hydraulic lifters, male sure engine oil is
fresh and at the proper level.
Sticky lifters can be the result of
sludge build up in the cylinder head and lifters.
- Run engine until it reaches normal operating temperature.
Shut off engine.
- Working inside luggage compartment, disconnect negative
battery cable.
CAUTION-
Prior to disconnecting battery cable, read the baltery dls-
connection cautions given In 001 General Cautions and
Warnings.
Disconnecting the battery may erase fault
code(s)
stored in control module memory Check for fault codes
4 Remove left and right interior ventilation duct (left side
shown):
Release plastic locking tab
(A) or release loclting tabs on
top of duct (later models).
Rotate duct counterclockwise to
unloclt from bulithead and
remove (arrow).
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Cylinder Head and valvetrain1
Camshaft removal and installation
(M62 engine)
Camshafts, removing (M62 engine)
Special
BMW service tools should always be used to remove
and install the camshafts. Removal of the camshafts without
the special tools can result in personal injury and lor cylinder
head damage.
NOTE-
Cylinder bank 1-4 is referred to as the right cylinder bank
and is located on the passenger side. Cylinder bank 5-8 is
referred to as the left cylinder bank and is located on the driv-
er's side.
WARNING-
Allow enqine to cool before beqinninq this procedure. 1
- Disconnect negative (-) cable from battery.
CAUTION-
Prior to disconnecting the battery, read the battery discon-
nection cautions
in 001 General Cautions and Warnings.
- Dra~n coolant. See 170 Radiator and Cooling System.
Remove plastic engine covers:
Press down on locking pins (arrows) and remove top
cover.
Pry out
trlm caps (A) from covers.
Remove fasteners from beneath
trlm caps and remove
side covers.
4 Remove left and right interior ventilation filter housing (lefl
side shown):
Release locking tabs
(A) or locking strap (early models,
not shown).
Rotate duct inward (arrow) to disconnect.
- Release spring lock (6) to unloclc ventilation housing.
Disconnect electrical harness from hood switch
(C).
Release locking clip and remove ventilation filter cover (0).
Remove filter housing.
Removal of right side ventilation duct is similar.
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.-
ignition System
Disabling ignition system
The ignition system operates in a lethal voltage range and
should be disabled any time engine service or repair work is
being done that requires the ignition to be switched on.
The engine management system can be disabled by remov-
ing the DME main relay. The relay is located in the electronics
box (E-box) in the left rear of the engine
compartment, be.
neath the interior microfilter housing.
CAUTION- Relay locations may
vary. Use care when identifying relays.
See
610 Electrical Component Locations.
Checking for spark
CAUTION-
If
a spark test is done incorrecth damage to the Engine Con-
trol Module
(ECM) or the ignition coils may result.
NOTE-
Spark plug replacement is covered in 020 Maintenance.
Check~ng for spark is d~fflcult on englnes wlth d~str~butorless
ignition systems.
Try removing the spark plugs and inspecting for differences between them.
A poor-firing plug may be wet with fuel and/or ~. - ~
black and sooty, but not always. If a coil is not operating, the
engine management system will electrically disable the fuel
injector to that cylinder. The key is to look for differences be-
tween cylinders.
Ignition coil assembly, testing and
replacing
C4 UTION-
Use a digital multimeter for the following tests. I
- Remove plastic engine cover from top of valve cover by pry-
ing off bolt covers and removing cover mounting bolts.
- Raise car slowly while constantly checking position of jack
and car.
- Disconnect harness connector from coil. Connect multimeter
between terminal 15
(+) in connector and ground.
4 Terminal identification are typically molded into connector. In
photo, terminals are from left to right: 1,
4a, 15.
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Battery, Starter, ~lternatorl
@ TO fuse & relay panel Battery Safety Terminal
A Battery Safety Terminal (BST) controlled by the Multiple
Restraint System (MRS) control unit was introduced for mod-
el year 1998
vehicles. The system will disconnect electrical
power to the engine compartment
in the event of a significant
impact. The MRS system fires an encapsulated pyrotechnic
device
in the positive (+) battery terminal that disconnects
power to the engine compartment, but maintains power to
the exterior lights and interior of the vehicle.
point
002125~1
Table a. Battery, alternator and starter troubleshooting
1-
/Starter motor or solenoid faulty. l~est starter.
Symptom
Engine does not crank
Engine cranks slowly or
not at all, solenoid
clicits
when starter is operated.
I I
Battery will not stay IShort circuit draining battery. l~est for excessive current drain with everything
Probable cause
Fault
in immobilizer system (EWS)
-Clean Battery cables loose, dirty or corroded.
Battery discharged.
Battery to body ground cable in trunk
loose,
dirty or corroded
Poor connection at starter motor terminal
30.
Corrective action
Try another ignition key. If problem persists, contact
your authorized BMW dealer.
or replace cables. See 020
~aintenance.
Charge battery and test. Replace if necessary.
inspect ground cable. Clean, tighten or replace if
necessary.
Checlc connections, test for voltage at starter. Test for
voltage at neutral safety or clutch
interloclc switch.
charged more than a few
days.
I~atter~ faulty. /Test battery and replace if necessary.
Short driving trips and high electrical drain
on
charging system does not allow battery to
recharge.
. I
I Battery cables loose, dirty or corroded. Iclean or replace cables. See 020 Maintenance.
Evaluate driving
style. Where possible, reduce
electrical
consumption when malting short trips.
Drive
belt@) loose, worn or damaged.
IAlternator or voltage regulator faulty. /Test alternator and voltage regulator.
Inspect
or replace ribbed
belt@). See 020
Maintenance.
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Battery, Starter, ~lternatorl
WARNING-
Always wear protective goggles and clothing when perform-
ing a load test.
Table
d. Battery load test - minimum voltage
Ambient temperature Voltage*
27
" C (80" F) 9.6 V
-I 8' C (0"
F) 8.5 V
* Measure
after applying a 200 amp load for 15 seconds.
Closed-circuit current measurement
If the vehicle battery is discharged for an unknown reason,
perform a closed-circuit current measurement as the first test.
For diagnostic purposes, it is important to not disconnect the
battery. Disconnecting the battery may reset a faulty control
unit, preventing proper diagnosis.
The following test is generally completed overnight using a
multimeterwith a closed circuitcurrent measurement adaptor
with a recording function
- Check that battery voltage is 12 volts or higher. If lower,
recharge battery.
- Switch off electrical consumers (interior lights, telephone,
aftermarket equipment, or others).
- Open luggage compartment and remove battery trim panel.
Use screwdriver to lock latch on trunk lid or hatch, simulating
closed luggage compartment. Close other doors.
- Open driver's door, then close it, simulating driver entering
vehicle.
- Switch ignition to RUN position for at least five seconds, then
turn ignition to OFF position. This simulates driving vehicle.
- Open and close driver's door, simulating driver leaving
vehicle.
- Lock car and arm alarm.
- Wait at least 16 minutes for consumer cut-off.