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j Cylinder Head Removal and Installation
4 Working at throttle housing, unscrew and disconnect electri-
cal harness plug
(arrow).
4 Disconnect electrical harness connector at fuel tank venting
valve
(A) and vent hose at quick disconnect fitting (arrow).
- Working under intake manifold, disconnect the following:
Engine oil dipstick tube support.
Oil separator return line from dipstick tube.
Knock sensor harness connector from support.
4 Working underneath car, remove intake manifold support
mounting nut
(arrow), located adjacent to left engine mount.
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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 - - .- - - - -
4 Disconnect electrical harness connections at exhaust cam-
shaft position sensor and exhaust camshaft VANOS control
valve (arrows).
4 Remove banjo bolt from VANOS unit oil pressure line. Use
banjo bolt to attach
BMW special tool 11 3 450 (compressed
air fitting) to VANOS control unit.
CAUTIOI\C
Oil will drain from pressure line. Have a drain container and
rags ready Do not allow oil to run onto drive belts.
4 Cover oil hole (arrow) in VANOS unit with shop towel to cap-
ture oil which will spray when compressed air is applied.
- Connect compressed air line to air fitting. Apply air pressure
set to
2-8 bar (30-1 15 psi).
4 With compressed air line connected, rotate engine at vibra-
tion damper in direction of rotation (clockwise) at least twice,
until cylinder 1 intake and exhaust camshaft lobes face each
other (arrows) in the top dead center (TDC) position for cyl-
inder
1.
CAUTION--
Do not rotate engine counterclocltwise to reach the top dead
center position. If engine rotated beyond top dead center;
complete another two complete rotations.
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11 3-31
Cylinder Head Removal and Installation
Remove sealing plug from special tool bore on lower left side
of engine block near flywheel. Secure crankshaft in TDC po-
sition with
BMW special tool l l 2 300 (arrow).
4 Unscrew and remove two cylinder head cover studs
(arrows) at rear of cylinder head.
4 Secure camshafts in TDC position using BMW special tool
set
11 3 240.
- Disconnect compressed air line, leaving compressed air fit
ting attached to VANOS unit.
4 Unscrew sealing plugs (arrows) from VANOS unit.
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[Cylinderead Removal -. . and Installation -7 - . ..
4 Oil will drain from plugs (arrows) when removed. Have a
container and rags ready. Do not allow oil to run onto drive
belts.
Pull sealing caps straight out of VANOS unit using short nee-
dle nose pliers.
NOTE-
Additional oil may drain from VANOS unit.
Remove set screws (left-hand thread) on ends of intake and
exhaust camshafts.
CAUTION-
Set screws have left-hand threads. Loosen in clocltwise di-
rection.
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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 --
Remove bolts (arrows) holding timing chain cover to cylinder
head. (Photo shows camshafts and camshaft bearing caps in
place).
4 Using BMW special tool 11 2 250 or equivalent, loosen cylin-
der head bolts in several stages, in sequence shown. Discard
head bolts.
NOJE-
BMW special tool 11 2 250 is a thin-walled Torx El2 socket
with an extended reach. The cylinder head bolts are re-
cessed into the head below the
camshaft towers with little
working space.
- Lift off cylinder head. Refer to 116 Cylinder Head and Val-
vetrain for cylinder head reconditioning information.
Cylinder head, installing, M52 TU and M54
engines
Clean cylinder head and gasket surfaces of cylinder bloclc
and all timing chain covers.
CAUTION- Remove foreign matter and liquid from bolt holes. Trapped oil
or coolant in bolt holes can cause damage to
blocl~,
CAUJION-
Do not use a metal scraper or wire brush to clean the alumi-
num cylinder head or pistons. If necessary, use a hard wood-
en orplastic scraper. Also available are abrasive discs to be
used in conjunction with an electric drill. Be sure to use the
correct disc for the type of metal being cleaned.
Evaluate cylinder head as shown in
116 Cylinder Head and
Valvetrain.
NOTE- If the cylinder head has been machined, a special 0.3
mm
(0.01 1 in.) thicker gasket should be installed. The thicker
gasket is available from an authorized
BMW dealer and
should be marked accordingly
Cylinder head and valve specifications are covered in 116
Cylinder Head and Valvetrain.