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11 3-25
Cylinder Head Removal and Installation
4 Working beneath car (on left side under driver seat), remove
fuel filter cover and clamp
off fuel hose(s).
NOTE-
M54 engines use a single fuel line to the non-return fuel rail.
Disconnect fuel lines by pressing in on spring lock (arrows).
CAUTION--
Fuel may be expelled underpressure. Do not smoke or worlc
near heaters or other fire hazards. Keep a fire extinguisher
handy Before disconnecting fuel hoses, wrap a cloth around
fuel hoses to absorb any leaking fuel. Plug all open fuel lines.
NOJE-
BMW uses various styles of line connections; a one-time
band clamp; a
self-locl(ing connector (that use BMWspecial
tool 16 1 050 to release); and a quick release connector
(above).
4 M52 TU engine: Pull throttle cable out of rubber retainer (A)
and unhook ball end of cable (6) from throttle actuator.
4 Remove fasteners retaining wiring harness at throttle body
and support bracket (arrows).
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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 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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- -
-- .- Cylinder ~ead~ernoval and Installation I - -.
Remove VANOS unit:
Remove engine lifting eye.
- Remove VANOS mounting nuts (arrows) and pull VANOS
unit and metal gasket off.
CAUTION-
Do not crank the engine with VANOS unit removed. Pis-
tonhalve inteiference may result.
NOTE-
The VANOS unit will contain a small quantity of oil. Place
shop towel to catch oil as unit is removed or tilted.
CAUTION-
If the VANOS adjustment unit is replaced, or if operations are
completed that may change the timing of
the camshafts, the
camshaft timing must be checked. See
11 7Camshaft Timing
Chain.
4 Remove primary camshaft chain tensioner cylinder (arrow).
CAUTION-
Primary camshaft chain tensioner is under spring pressure.
Press down on secondary chain tensionerand lock into place
using
BMW special tool 11 3 291, or a thin drifl or pin.
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11 3-40
I Cylinder Head Removal and Installation
Lubricate camshafts, camshaft carriers, bearing caps, hy-
draulic lifters, friction washers, splined shafts and spline hubs
with assembly lubricant before installation.
4 Check that two cylinder head aligning sleeves (arrows) are
correctly positioned in block and are not damaged.
- Apply elastic sealing compound Three Bond 1209 8 to cor-
ner joints on cylinder block to timing chain cover.
- Place new cylinder head gasket on cylinder block.
NOTE-
The word "OBEN" or "TOP printed on the gasket, should
face up. The cylinder headgaslet will fit correctly in only one
orientation.
- Set cylinder head in position, guiding primary chain through
cylinder head opening.
CAUJION-
Make sure the crankshaft, which had been rotated approxi-
mately 30" opposite the direction of engine rotation from
TDC, is still in thatposition before lowering the cylinder head
into position. All pistons must be out of TDC position to pre-
vent
valve/piston interference when the camshafts are in-
stalled.
- Lightly lubricate new cylinder head bolts and washers with
oil. Install bolts and washers finger tight. Install cylinder head
to lower timing chain cover bolts finger tight.
NOJE-
Cylinder head bolts should not be reused. They are
stretch-type bolts and must be replaced whenever loos-
ened.
* Aluminum cylinder blocls use different length cylinder
head bolts and torque values than cast iron blocks.
Check that all washers for
Nle head bolts are in place be-
fore installing the bolts. Some of the washers may be
staked to the cylinder head.
I 12 10 4 2 6 8 141 Tighten cylinder head bolts in correct sequence (1-14)
CA U TIOW-
The bolts should be tightened in three stages as listed below
The final stages require the use of a BMW special tool
11 2
110 or a suitable protractor to tighten the bolts to a specified
torque angle.
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. - ..
Cylinder Head Removal and installation] --
- Secure cylinder head bolts by torquing an additional 90"
each for Stage 2 and 3.
Tightening torques
Cylinder head to engine block
(aluminum block)
Stage
1 40 Nm (30 it-lb)
Stage 2 +90°
Stage 3 80'
4 lnstall intake camshaft position sensor (arrow).
4 Install lower secondary chain guide. Tighten tom bolts to
specifications. The bolt on the intake camshaft side is long
and extends into the engine block.
4 Install and tighten cylinder head-to-lower timing chain cover
bolts (arrows). (Photo shows camshafts in place).
Tightening torque Secondary chain guide to cylinder head
10 Nm (89 in-lb)
Cylinder head to lower timing chain cover
M6 10 Nm (89 in-lb)
M7 15 Nm (1 1 it-lb)
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Cylinder Head Removal and Installation
4 While maintaining tension on timing chain, rotate crankshaft
at vibration damper from
30" before TDC in direction of rota-
tion (clockwise) until number
1 cylinder is at TDC position
with line between the
OIT (arrow) on front pulley lined up
with boss on lower timing chain cover.