Page 303 of 1002

Downloaded from www.Manualslib.com manuals search engine
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.
Page 304 of 1002
Downloaded from www.Manualslib.com manuals search engine
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.
Page 305 of 1002
Downloaded from www.Manualslib.com manuals search engine
-
Camshaft Timing chain1
4 Remove oil lines from camshaft supports (arrows).
- Remove radiator cooling fan and fan shroud. See 170 Radi-
ator and Cooling System.
NOTE-
The radiator cooling fan nut (32 mm wrench) has left-hand
threads.
- Remove engine drive belts alternator and AlC compressor.
See
020 Maintenance.
4 Remove vibration damper bolts (arrows) and remove
damper.
4 Mount BMW special tool 11 2 450 to crankshaft hub while
aligning damper locator pin with hole (arrow) in special tool.
CAUTION-
Crankshaft center bolt is torqued to 410 Nm (300 ft-lb) use
BMWspecial tool I I 2 450 to secure crankshaft when remov-
ing center bolt.
- Loosen and remove cranltshaff center bolt.
Page 306 of 1002
Downloaded from www.Manualslib.com manuals search engine
I Camshaft Timins Chain
4 Using special tool 11 2 450, rotate engine clocltwise to TDC
with number one cylinder cam lobes facing each other (ar-
rows)
as shown.
4 Lock crankshaft in TDC position with BMW special tool 11 3
200 (arrow).
- Remove BMW special tool 11 2 450 and remove hub.
- Remove upper engine oil pan. See 119 Lubrication.
- Remove alternator. See 121 Battery, Starter, Alternator.
- Remove retaining bolt for oil dipstick tube from upper timing
chain cover on right side.
- Remove camshaft position sensor from right upper timing
chain cover.
< Remove right upper timing chain cover:
Remove chain tensioner
(A).
CAUTIOG
Tensioner is under spring tension. Release slowly. 1
Release fasteners (arrows) and remove cover
Page 307 of 1002
Downloaded from www.Manualslib.com manuals search engine
Camshaft Timing chain1
< Remove Automatic Stability Control (ASC) throttle body:
Disconnect electrical harness from throttle position sensor.
Disconnect ASC actuator cable (arrow).
Remove
3 mounting fasteners and remove throttle body.
4 Disconnect fuel tank vent valve line and cap off line (arrow).
- Drain engine coolant and remove hoses from thermostat
housing. See
170 Radiator and Cooling System.
- Remove water pump and thermostat housing. See 170 Ra-
diator and Cooling System.
- Remove left side upper timing chain cover retaining bolts and
remove cover.
4 Counter hold right intake camshaft
CAUTION-
Counter hold camshaft with a 27mm open-end wrench while
loosening sprocket bolts. Grind wrench if necessary to pre-
vent damage to head.
Page 308 of 1002
Downloaded from www.Manualslib.com manuals search engine
1 17-72
Camshaft Timing Chain
4 Working at right side cylinder head loosen Intake camshaft
sprocket bolts
(arrows).
4 Secure left and right side camshafts in TDC position:
Use BMW special tool set
11 2 440.
- If necessary, turn camshaft so that special tools are
squarely seated on cylinder head.
Working at left cylinder head loosen
intake camshaft
sprocket bolts
(arrows).
CAUTION-
Counter hold camshaft with a 27mm open-end wrench while
loosening sprocket bolts. Grind wrench
if necessary to pre-
vent damage to head.
Remove BMW special tool
11 2 300 from crankshaft locking
tool bore.
Page 309 of 1002
Downloaded from www.Manualslib.com manuals search engine
1 Camshaft Timing Chain
4 Secure right side timing chain and guide rails together with a
plastic wire ties
(arrow).
4 Remove lower timing chain cover bolts (arrows) and cover.
- Remove wire ties supporting guide rails.
-
Q Remove sprocket from intake camshafts and remove timing
chain.
If necessary, remove tensioning rail
(A), reversing rail (B),
and guide rail (C) to remove timing chain.
Page 310 of 1002

Downloaded from www.Manualslib.com manuals search engine
I Camshaft Timina Chain
/ Cylinders 5-8
Timing chains, installing
(M62 engine to 911 998)
4 The procedure outlined below assumes that the camshafts
are locked in the TDC installation position with special lock-
ing tools as shown earlier.
4 lnspect timing chain sprocltets and chain. Inspect guide rail
and tensioner rail
(arrows) for grooves caused by chain con-
tact. Replace any part that is worn or damaged.
NOTE-
If any sprocl(ets are being replaced due to wear, the chain
should also be replaced.
If the crankshaft sprocket requires
replacement, the oil pump
drive sprocket and chain must be
removed. See
119 Lubrication System for oilpump removal
information.
- If removed, reinstall timing chain tensioning rail, reversing
rail, and guide rail.
If tensioning rail was removed, replace O-ring at tensioning
rail oil guide.
Tightening torque Reversing rail
to engine block 14 Nrn (10 n-lb)
4 lnstall timing chain and intalte sprocket to intake camshaft on
left cylinder head. Center bores of camshaft flange in sprock-
et mounting slots. Install two mounting bolts finger tight.