2001 BMW 525i cylinder head bolt

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I Cylinder Head Removal and Installation
4 Check that two locating dowels are correctly positioned in
block and are not damaged.
- Apply permanently elastic sealing compound Three Bond
1209 8 to joints where cylinder block joins timing case cover.
- Place new cylinder head gasket on cylinder block.
NOTE-
The word "OBEN" or 'TOP': printed on the gasket, should
face up. The cylinder head
gasket will fit correctly in only one
orientation.
- With camshafts locked in TDC oosition with BMW soecial
tools as described during cylinder head removal,
seicylinder
head in position, guiding primary chain through cylinder head
opening.
NOTE-
* The camshafts must be locl(ed in the TDC position at the
rear of the cylinder head with
BMW special tool I1 3 240
before installing the cylinder head.
Make sure the
cranksha% which had been rotated approx-
imately
30" opposite the direction of engine rotation, is still
in that position before lowering the cylinder head into posi-
tion.
- Lightly lubricate new cylinder head bolts. Loosely install bolts
and their washers, then thread them in until they are finger
tight.
NOTE-
. Torx-type cylinder head bolts should not be reused. They
are stretch-type bolts and must always be replaced when-
ever loosened.
Check that all washers for the cylinder head bolts are in
place before installing the bolts. Some of the washers may
be
stalced to the cylinder head.
CAUTIOI\C
Cylinder head bolts for a cast iron engine block are different
length and require different tightening torque than bolts for an
aluminum cylinder bloclc engines
(95 rnm versus 110 rnm
bolts).
- Install cylinder head-to-lower timing chain cover bolts finger
tight.
< Tighten cylinder head bolts in correct sequence to initial
torque value.

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I Cylinder Head Removal and Installation I
< Use BMW tool 11 2 110 or torque angle gauge to tighten cyl-
inder head bolts in sequence to stage
2 and 3.
Tightening torques
Cylinder head to cast iron
bloclc
Staoe 1
staie 2
Stage 3
Cyllnder head to aiumlnum block
Stage
1 40 Nm (30 it-lb)
Stage 2 +90°
Staoe 3 -80"
- Tighten cylinder head-to-lower timing chain cover bolts.
Tightening torques
cylinderhead to lower timing chain cover 10 Nm (89 in-lb)
- Inspect secondary chain guide rail and tensioner rail for
grooves caused by chain contact. Replace any part that is
worn.
NOTE-
Inspect timing chain sprocl(ets. Sprockets that have worn
or missing teeth should be replaced.
* If any of the sprockets are being replaced due to wear, the
chain should also be replaced.
If the crankshaft sproclet requir?s replacement, the oil
pump drive sprocket and chain must be removed as de-
scribed under
119 Lubrication System.
The procedure outlined below assumes that the camshafts
and the
cranl(shaft are locledin the TDCposition with special
4 Mount primary timing chain sprocltet to primary chain so that
arrow on sprocket faces up. Mount sprocket to camshaft so
that tapped holes in camshaft are on left side of elongated
holes in sprocltet
Install BMW special tool
1 I 4 220 into primary timing chain
tensioner sleeve. Thread center spindle in finger tight
until
slack is removed from chain.

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--
Cylinder Head Removal and Installation
NOTE-
BMW special tool 11 4 220 is an adjustable primary chain
tensioner and simulates the function of the hydraulic
tensioner.
- Check that elongated holes in primary sprocket are now cen-
tered to bolt holes in camshaft and chain is free of slack. If
not, reposition sprocket to chain and reinstall.
- lnstall secondary timing chain guide and secondary chain
tensioner. Tighten mounting bolts (tensioner remains locked
down for now using
BMW special tool 11 3 292).
- Install cylinder identification trigger plate to front of intake
camshaft with studs.
- Install spacer to front of intake camshaft.
- Install secondary chain sprockets and chain as an assembly
so that arrows on sprockets are pointing up. Center mounting
holes in sprockets to bolt holes in camshafts.
4 lnstall thrust washers and diaphragm spring to intake cam
sprocket.
I 2hm thrust washer I
- Install shim and torx bolts to exhaust camshaft. Tighten fin-
ger tight; do not torque down.
- Tighten intake sprocket nuts.
CA UTIOG
Hold the camshaft stationary (at hex on camshaft) when loos-
enino or tiahtenino sorocket mounting bolts and studs.
Tightening torque
Intake s~rocket nuts to studs 10 +l Nm (89 +9 in-lb)
- Turn crankshaft approx. 30" in direction of rotation to bring
engine to TDC. Lock crankshaft in TDC position with BMW
special tool
11 2 300.
CAUTION-
The camshafts andcranlshaft must be lockedin the TDCpo-
sition using BMW special tools 11 2 300 and 11 3 240. If the
camshafts and cranl(shaft are not at TDC, the valves can
contact the pistons.

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- -.
Cylinder Head Removal and lnstallation
NOTE-
Be Sure the secondary timing chain tensioner is locked down
and the exhaust
camshaif mounting bolts are loose before
proceeding.
- Install VANOS control unit. See VANOS control unit, install-
ing
(M52 engine) in 117 Camshaft Timing Chain.
CAUTION--
Incorrect installation ofthe VANOS control may result in dam-
age to the engine valvefrain.
- Install exhaust manifolds using new gaskets and nuts. Coat
manifold studs with copper paste prior to installing nuts.
Install intake camshaft cover and cylinder
head cover.
Check for correct seating of half-moon seals
(A) in back of
cylinder head cover.
Use a small amount of Three Bond 1209
O or equivalent
sealant at corners
(6) of half-moon cutouts.
Seat gasket and seal corners in front of cylinder head at
VANOS unit.
- Installation of remaining parts is reverse of removal, noting
the following:
Reinstall electrical harness connectors for oil pressure
switch and coolant temperature sensor before installing in-
take manifold.
Refill cooling system as described in 170 Radiator and
Cooling System.
Change engine oil and filter as described in 020 Mainte-
nance.
If necessary, adjust accelerator cable.
Reconnect battery last.
Tightening Torques
VANOS oil line
32 Nm (24
ft-lb)
VANOS solenoid to control unit 30 Nm (22 ft-lb)
Coolant drain plug to cylinder
block 25 Nm (18 ft-lb)
Cylinder head cover to cylinder head
10 Nrn (89 in-lb)
(M6 bolts)
intake manifold to cylinder head 15 Nm (I 1 ft-lb)
Radiator cooling fan to coolant pump
40 Nm (30 ft-lb) - . .
Radiator drain screw to radiator 2.5 Nm (22 in-lbl

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11 3-27
Cylinder Head Removal and Installation
< Remove fuel rail mounting bolts (arrows):
- Carefully pry fuel rail off manifold.
Separate fuel line support bracket at rear of intake mani-
fold.
Guide fuel
line(s) out of rear of engine compartment while
lifting fuel rail out.
4 Remove intake manifold mountino hardware (arrows).
I from falling into the engine intake. I
4 Remove cylinder head top cover:
- Remove plastic trim caps (arrows).
Remove cover hold down fasteners and
lilt off cover.

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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.