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I Cylinder Head Removal and Installation
4 Drain engine coolant and remove coolant hoses:
Remove expansion tank cap on radiator.
Place a
3 gallon pail beneath engine to capture coolant
Remove coolant drain plug (arrow) located on exhaust
side of cylinder
2 of engine block.
4 Drain radiator into a 3 gallon pail by removing plastic drain
plug (arrow) completely.
Use caution when draining and disposing of engine coolant.
Coolant is poisonous andlethal to humans andpets. Pets are
attracted to coolant because of its sweet smell and taste.
Seek medical
attention immediately if coolant is ingested.
NOTE-
Catch and dispose of drained coolant according to local,
state, and federal laws.
4 Remove thermostat housing:
. Disconnect electrical harness connector at thermostat
housing.
. Remove hoses from thermostat hous~ng by releasing loclts
(arrows).
Unbolt
(4 bolts) and remove thermostat hous~ng.
- On vehicles equipped with mechanical cooling fan: Remove
belt-driven cooling fan and radiator shroud as described in
170 Radiator and Cooling System.
CAUTIOI\C
32 mm radiator fan mounting nut has left hand threads. r
4 Remove fasteners (arrows) from heater bypass tube. Pull
tube out of cylinder head and set to side, leaving heater hose
connected.
- Unbolt power steering fluid reservoir and pull aside without
disconnecting hoses. Secure to fender with cord or stiff wire.
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Cylinder Head Removal and Installation
4 If applicable, remove secondary air injection pump:
Disconnect hose at one-way valve
(A).
Remove bolts at support bracket on strut tower (arrows).
Disconnect electrical harness from bottom of secondary
air injection pump.
Remove mounting bracket from strut tower.
4 Remove ignition coils:
* Disconnect ignition coil harness connectors.
Remove coil mounting fasteners.
Remove coils.
* Remove ground straps.
CA UTIOI\C
Note location of all ground wires. Failure to reinstall grounds
can result in permanent damage to engine control module or
ignition system components.
Set coil harness to side of engine compartment
- Remove cylinder head cover mounting fasteners and remove
cylinder head cover.
NOTE-
The cylinder head cover mounting bolt insulators and gas-
ltets should be reinstalled in their original locations. Male
note of their arrangement during removal.
- Remove spark plugs
4 Remove oil baffle cover from above intake camshaft.
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Cylinder Head Removal and Installation I
Remove cylinder head cover mounting studs (arrows) from
center of cylinder head.
- Remove crankshaft loclting tool from transmission bell hous-
Ing.
Lift primary chain and hold under tension, then rotate engine
at vibration damper in opposite direction of normal rotation
(counterclocltwise) approximately 30".
CAUTION-
By turning crankshait3O0, pistons are movedaway from top
dead center, to prevent possible valve interference to pistons
during camshaft servicing.
- Remove camshaft loclting tools (BMW special tool set 11 3
240) from rear of cylinder head.
4 Remove camshaft bearing cap 1 on intake camshaft.
4 Fit BMW special tools 11 3 260 (A) and 11 3 270 (B) to cyl-
inder head and screw long bolts (arrows) into spark plug
threads. Tensioning pins on tool will align with the bearing
caps on the
intake camshaft.
CAUJION-
Do not over torque bolts into sparkplug holes.
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Cylinder Head Removal and Installation
4 Rotate camshafts until intake and exhaust lobes for cylinder
1 face each other (arrows).
CAUTION-
Be sure that cranlcshaft is stillpositioned at least 30" away
from
TDC.
- Place bearing caps on cams, but do not install retaining nuts.
4 Fit BMW special tool 11 3 260 (A) and 11 3 270 (B) to cylin-
der head over intake camshaft and screw long bolts (arrows)
into spark plug threads.
CAUTIOI\C
Do not overtighten bolts in spark plug holes.
Turn eccentric shaft of special tool to pretension
bearing
caps. Install and torque nuts on intake camshaft bearing
caps.
Tightening torque Camshaft bearing
cap to cylinder head (M7) 14 Nm (10 ft-lb)
Release tension on eccentric
shaft and remove BMW special
tools
11 3 2601270.
Repeat procedure for exhaust camshaft.
CAUTION-
After the camshafts are installed, a minimum waiting time is
required for the hydraulic lifters to 'bleed down" before bring-
ing the crankshaft andpiston back to top
deadcenter. When
the camshafts are removed, the hydraulic lifters can expand.
This expansion can cause increased valve lift when the cam-
shafts are bolted down, possibly resulting in piston interfer-
ence.
Crankshaft
I valve timing waiting times
68.F (20°C) and higher 4 minutes
50-68"F(10-20°C) 11 minutes
32-5O0F(O-10°C) 30 minutes
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.
Cylinder Head and Valvetrain
< Remove cylinder head cover retaining studs (arrows) from
center and rear of cylinder head.
< Remove spark plugs and install BMW special tool 11 3 260
(A) and 11 3 270 (6) to cylinder head. Tighten tool retaining
bolts in spark plug bores. Do not overtighten bolts.
Tightening
torque
BMW special tool 11 3 260 I1 1 3 270 to 23 Nm (17 It-lb)
cylinder head
- Remove intake camshaft bearing cap for cylinder number 1.
CA UTIOG
Intake camshaft bearing cap 1 is centered with adapter
sleeves. To avoid
can~sllaft daniage, it must be removed bs-
fore any other caps.
Turn eccentric shaft on special tool until pressure is applied
to camshaft bearing caps.
- Remove remaining bearing cap mounting nuts
- Slowly release pressure on camshaft bearing caps by turning
eccentric shaft. Remove bearing caps and camshaft. Repeat
procedure on remaining camshaft.
CAUTION-
Camshaft bearing caps must be reinstalled in their original lo-
cations.
NOTE-
The camshaft bearing caps are coded with a letter anda
number. For example,
'XI" is the first exhaust camshaft
bearing cap at the front of the engine, and
"El "is the intalce
camshaft bearing cap at the front of the engine.
0 The camshafts are stamped with a code letter - "E" for the
intake side and 'MA" for the exhaust side.
0 "E is for Einlap, (German for intake) and 'XA"is for Auspuff,
(German for exhaust).
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..--.
I Cylinder Head and Valvetrain - I
4 Lift primary chain and hold under tension, rotate engine
against direction of rotation (counterclockwise) approximate-
ly 30".
To prevent damaging valves while
worlcing on camshafts, no
aistons should be in the TDC position.
- Remove BMW special tool set 1 I 3 240 from rear of cylinder
head.
Remove retaining nuts (arrows) and bearing cap
1 of intake
camshaft.
Intake camshaft bearing cap
1 is centered with adapter
sleeves. To avoid camshaft damage, it must be removed be-
fore anv other caos.
4 Fit BMW special tools 11 3 260 (A) and 11 3 270 (B) to cylin-
der head and screw long bolts (aiiows) into spark plug
threads. Tensioners will align with the bearing caps on the in-
take camshaft.
CA UTION--
Do not over torque bolts into spark plug holes. 1
4 Turn eccentric shaft of special tool to pretension intake carn-
shaft bearing caps. Remove nuts on remaining bearing caps.
- Slowly release tension on eccentric shaft and remove BMW
special tools. Remove bearing caps and set aside in order.
Remove camshaft and store safely.
CA U TIOW-
Camshaft bearing caps must be installed in their original lo-
cations.
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Cylinder Head and Valvetrain
4 Rotate camshafts so that intalte and exhaust lobes for cylin-
der
1 face each other (arrows).
CAUJION-
A minimum waiting time is required for the hydraulic lifters to
'bleed down"after installing the camshafts into the cylinder
head, before bringing the piston to TDC. When the camshafts
are removed, the hydraulic lifters can expand. This expan-
sion can cause increased valve lift when the camshafts are
bolted down, possibly resulting in piston interference.
Place bearing caps on cams, but do not install retaining nuts.
4 Fit BMW special tool 11 3 260 (A) and 11 3 270 (B) to cylinder
head over
intalte camshaft and screw long bolts (arrows)
into spark plug threads.
CA UTION-
Do not overtighten bolts into spark plug holes.
< Turn eccentric shaft of special tool to pretension bearing
caps. Install and torque nuts on intake camshaft bearing
caps.
Tightening torque Camshaft bearing cap
to cylinder head (M7) 14 Nm (10 it-ib)
- Release tension on eccentric shaft and remove BMW special
tools
11 3 2601270.
- Repeat procedure for exhaust camshaft.
NOTE-
Observe waiting time for lifter bleed down before continuing
with camshaff installation.
Crankshaft
I valve timing waiting times
68°F (20°C) and higher 5 minutes
50-6S°F(10-20°C) 15 minutes
32-50DF(O-10°C) 30 minutes
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Camshaft Timing Chain/ - - - - - - . - - . - .
Tighten exhaust camshaft sprocket mounting bolts (arrows)
alternately in two stages.
Tightening torques
Secondary timing chain sprocltets to camshafts
Stage
1
Stage 2
5 Nm (44 in-lb)
22 Nm (17 ft-lb)
- Remove crankshaft locking tool and camshaft locking tool
set.
- install camshaft gear bolt access plugs using new sealing
washers and tighten.
- Remove timing chain tensioning tool from side of cylinder
head. Install primary chain tensioner with new sealing wash-
er and tighten.
Tightening torques
Access plugs to VANOS control unit 50 Nm (37 ft-lb)
Primary timing chain tensioner
plug to 70 Nm (52 ft-lb)
tensioner sleeve
- Check adjustment VANOS system, see VANOS timing,
checking and adjusting
(M52 engine).