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Cylinder Head and Valvetrain
< Disconnect fuel injector electrical connectors from injectors.
Pry corner of wire lock clip (arrow) on first injector.
* Repeat for all injectors.
Lift wiring ducts off and set aside.
4 Remove right and left side ignition coil mounting nuts (ar-
rows) and coils.
NOTE-
Male note of location for ground straps (arrow A).
- Remove spark plugs.
- Disconnect positive (+)jumper junction from top of lefl cylin-
der head cover.
4 Remove retaining nuts (arrows) and remove oil lines from
left and right cylinder heads.
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1 17-2
Camshaft Timing Chain
This repair group covers timing chain and VANOS repair
information for the following engines:
M52 (Single VANOS 6-cylinder engine)
M52
TU and M54 (Double VANOS engines)
M62 (Non VANOS
V-8 engine)
NOTE-
The M62 TU V-8 engine with VANOS Variable Camshaft
Timing repair information is not included.
NOTE-
See 100 Engine General for engine code and application
information.
Worn timing chains and sprocltets can lead to noisy operation
and erratic valve timing. Afaulty tensionercan also cause tim-
ing chain noises.
For specific repair procedures, refer to the appropriate repair
group:
020 Maintenance
113 Cylinder Head Removal and Installation
119 Lubrication System
121 Ignition System
170 Radiator and Cooling System
Special tools
Special BMW service tools are needed to perform the service
and repairs procedures covered in this repair group. Many of
these tools are expensive and only available through an au-
thorized BMW dealer. Be sure to read each procedure thor-
oughly before starting a job to determine which special tools
will be necessary.
In addition, Double VANOS system diagnosis can only be
carried out by using BMW specific electronic scan tools, such
as BMW
DISplus, MoDiC or equivalent.
4 Torque wrench wl flex extension
(Tool No. BMW 00
9 250)
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Camshaft Timina chain1
- Remove viscous clutch cooling fan. See 170 Radiator and
Cooling
System.
CA UTlOEIC
The radiator cooling fan nut (32mm wrench) has left- hand
threads.
.
< Remove engine trim covers:
Pry out plastic trim caps (arrows).
. Remove cover fasteners and covers.
4 Remove ignition coils:
0 Disconnect ignition coil electrical harness connectors
Remove
coil mounting fasteners and remove coils.
Remove spark plugs.
NOTE-
Make note of ignition coil ground strap locations.
Disconnect VANOS electrical harness connector
(A) and oil
line fitting
(B) from VANOS control unit.
NOTE-
Wrap the VANOS oil line fitting with a shop rag to absorb
leaking oil.
- Disconnect cranltcase breather by squeezing at arrows,
- Remove cylinder cover mounting fasteners and remove
cylinder head cover.
NOTE-
The cylinder head cover mounting bolt insulators and gas.
kets should be reinstalled in their original positions. Make
note of their arrangement during removal.
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Camshaft Timing Chain
VANOS timing, checking and adjusting
(M52 engine)
NOTE-
* Special BMW service tools are required to remove and in-
stall the VANOS control unit. Read the procedure through
before starting the job.
If the camshafts are not properly timed, the pistons can
contact the valves.
- Disconnect negative (-) cable from battery.
CAUTIOG Disconnecting the battery may erase
faultcode(s) storedin
control module memory. Prior to disconnecting the battery,
checlc for fault codes using special BMW diagnostic equip-
ment.
Prior to disconnecting the battery, read the battery dis-
connection cautions given in
001 General Cautions
and Warnings.
- Remove viscous clutch cooling fan. See 170 Radiator and
Cooling
System.
CAUTIOG The radiator cooling fan nut
(32 mm wrench) has left-hand
threads.
4 Remove ignition coils:
Disconnect ignition coil electrical harness connectors.
Remove coil mounting fasteners and remove coils.
Remove
spark plugs.
NOTE-
Make note of ignition coil ground strap locations.
Page 273 of 1002
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Camshaft Timing Chain
VANOS control unit, removing
(M52 TU and M54 engines)
This procedure includes removal of the Double VANOS con-
trol unit.
NOTE-
If the Double VANOS control unit is being replaced, camshaft
timing must be checked. This procedure requires multiple
special tools. Be sure to read the procedures through before
beginning the repair.
- Working inside luggage compartment, disconnect negative
(-) battery cable.
Prior to disconnecting the
batteg read the battery discon-
nection cautions given in
001 General Cautions and
Remove engine cooling fan assembly. See 170 Radiator
and Cooling System.
Remove engine trim covers.
Pry out plastic trim caps (arrows).
Remove cover fasteners, oil filler cap, and covers.
Remove ignition coils:
Disconnect ignition coil electrical harness connectors.
Remove coil mounting fasteners and coils.
NOTE-
Make note of ignition coil ground strap locations.
Remove spark plugs,
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-- - -- - -- Camshaft Timing chain1
- Remove camshaft locking tools from rear of camshafts
- Remove BMW special tool 11 4 220 (adjustable primary
chain tensioner). Reinstall primary chain tensioner.
Tightening torque Primary chain tensioner to cylinder head
70
Nm (52 it-lb)
- Remove crankshaft locking tool from transmission bellhous-
ing. Reinstall sealing plug.
- Remove VANOS setup bracket from front of cylinder head
- lnstall VANOS control unit as described earlier in this group.
- Remove compressed air fitting (BMW special tool 11 3 450)
from VANOS control unit.
- Fit VANOS oil line banjo bolt with new seals. Attach oil line to
VANOS control unit.
Tightening torque
Oil line to VANOS control unit (banjo bolt) 32 Nm (24 H-lb)
- Remainder of installation is reverse of removal, noting the fol-
lowing:
lnstall spark plugs.
* lnstall intake camshaft plastic baffle prior to installing cylin-
der head cover. lnstall ignition coil packs and connect elec-
trical harness connectors.
Install radiator cooling fan.
- lnstall air filter housing and top engine cover.
Tightening torque Radiator cooling fan
(VISCOUS clutch) to 40 Nm (30 ft-lb)
coolant pump
Cyitnder head cover to cylinder head 10 Nm (89 in-lb)
Sparlc plug to cylinder head 25 Nm (18 ft-lb)
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Camshaft Timing chain1
- Disconnect negative cable (-) from battery.
CAUTION-
Prior to disconnecting the battery, read the battery discon-
nection cautions given
in 001 General Cautions and
Warnings.
4 Removing top and side engine covers:
Press down on locking pins (arrows) to release locks. Lifl
intake manifold cover straight up to remove.
Pry out caps from side covers.
Remove fasteners
and covers.
NOTE-
Some early models use
pry out trim caps and fasteners to
hold the top cover in place.
Disconnect electrical harness connectors at ignition coils
(A).
Remove left and right side ignition coil mounting fasteners
and coils.
NOTE-
Make note of location of ground strap (arrow).
Remove spark plugs.
- Remove posltlve (+) terminal cable from left cylrnder head
cover.
- Unbolt left and right side cable ducts from fuel rail
Remove air filter housing and mass air flow sensor:
Disconnect mass air flow sensor and intake air tempera-
ture sensor electrical harnesses
(A and B).
Remove air filter housing mounting fastener (arrow)
Loosen intake hose clamp
(C).
Remove air filter housing with mass air sensor and intake
duct from throttle body assembly.
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1 17-68
Camshaft Timing Chain
4 Remove left and right side ignition coils and spark plugs:
- Remove positive (+) terminal cable from left cylinder head
cover.
- Unbolt lefl and right side cable ducts from fuel rail,
4 Disconnect fuel injector electrical connectors:
Pry corner of wire lock clip to release connector from injec-
tor
(arrow).
Repeat for all injectors.
Lift off wiring ducts.
4 Remove Fasteners (arrow) from lefl and right cylinder head
cover fasteners and remove covers.