1997 BMW 525i cool

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Cvlinder Head Removal and Installation /
Right cylinder head, installing, M62 engine
- Clean cylinder head and block sealing surfaces of gasket de-
bris, making sure no debris drops into coolant or oil passag-
es.
CA UTIOW-
To prevent valve to piston contact when tightening camshaft
sprocket fasteners, counterhold camshaft with
27 mm open-
end wrench. If
necessarq: grind outer side of wrench jaws to
prevent damaging cylinder head.
- Check cylinder head bolt holes and condition of threads. Re-
move debris and liquids from holes.
4 Check cylinder head locator sleeves (arrows) for damage
CAUTION-
lithe cylinder head has been machined, a special 0.3 rnm
(0.01 1 in.) thickergasket should be installed. The thickergas-
ket is available through an authorized BMW dealer and
should be marked
accordinglw
- Place new cylinder head gasket over locating sleeve on
block.
< The word "OBEN" or "TOP (arrow) printed on the gasket.
must face up.
CAUTION-
Male sure the crankshaft, which had been rotated approxi-
mately
45" opposite the direction of engine rotation from
TDC, is
stillin thatposition before installing the cylinder head.
All pistons must be out of
TDCposition to prevent valve/pis-
ton contact
- Install new cylinder head bolts and washers finger tight. Be
sure not to remove coating from bolts.
4 Tighten cylinder head bolts in correct sequence (1 -10) to
stage
1 torque values.

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1 13-82
1 Cylinder Head Removal and Installation
4 Reinstall cylinder head covers to right and left cylinder heads
using new gaskets.
Check for correct seating of half-moon seals
(A) in back of
cylinder head cover.
Use a small amount of Three Bond
1209 8 or equivalent
sealer at corners
(B) of half-moon cutouts.
- Install cylinder head cover fasteners and tighten uniformly in
'I2 turn steps.
Tightening torque Cvlinder head cover fasteners
10 Nm (7.5 It-lb)
- Install exhaust manifolds using new gaskets and fasteners.
See
180 Exhaust System.
- Refill and bleed cooling system as described in 170 Radiator
and Cooling System.
- Change engine oil and filter as described in 020 Mainte.
nance.
CA UTIOW-
To prevent damaging engine electricalsystems, be sure to in-
stall all ground wires previously removed.
Tightening
tOrqUeS
Camshaft sprocket to camshaft 15 Nm (1 1 ft-lb)
Coolant manifold to cylinder head lo Nm (7.5 It-lb)
Cylinder head cover nuts 10 Nm (7.5 ft-lb)
Exhaust manifold to head 22 Nm (17 ft-lb)
Engine mount to subframe 42 Nm (30 ft-lb)
Spark plugs to cylinder head 22 Nm (17 ft-lb)

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116-12
I Cylinder Head and Valvetrain
Camshaft and lifter removal and installation
(M52 engine)
Camshafts and lifters, removing (M52 engine)
WARNING
-
The process of evenly loosening the camshaft bearing cap
nuts is NOT an acceptable method of removing the cam-
shafts. Special tools should always be used to remove the
camshafts. Be sure to read the procedure
tlirough before
starting a job.
I Allow engine to cool before beginning this procedure. /
- Disconnect negative (-) cable from battery.
CAUTION-
Prior to disconnecting the batfew read the battery discon-
nection cautions given in
001 General Cautions and
Warnings.
- Remove VANOS control unit from cylinder head. See 117
Camshaft Timing Chain.
I I 4 Remove loosened bolts (arrows) from front of exhaust
sprocket
nuts
(arrows) from intake camshaft

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Cylinder Head and valvetrain1
- Remainder of installation is reverse of removal, noting the
following:
See
117 Camshaft Timing Chain for VANOS control unit
installation.
Tightening torques
Camshaft bearing caps
to cylinder head (M7) 15 Nm (1 1 ft-lb)
Cylinder head cover to cylinder head (M6) 10 Nm (89 in-lb)
Sparic plugs (M12) 23 Nm (17 ft-lb)
Camshaft and lifter, removal and
installation
(M52 TU and M54 engine)
Camshafts and lifters, removing
(M52 TU and M54 engine)
WARNING-
Allow engine fo cool before beginning this procedure.
- Disconnect negative (-) cable from battery.
CAUTION--
Prior to disconnecting the battea read the battery discon-
nection cautions in
001 General Cautions and Warnings.
Remove VANOS control unit. See 117 Camshaii Timing
Chain.
Remove primary timing chain tensioner (arrow).
CAUTION-
Primary timing chain tensioner is under spring pressure. 1

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I Cylinder Head and Valvetrain
- Remove adjustable primary timing chain tensioner tool and
reinstall primary chain tensioner cylinder to cylinder head.
Tightening torque
Primary chain tensioner cylinder
to 70 Nm (52 ft-lb)
cylinder head
- Remove flywheel locking tool from crankcase. Replace spe-
cial tool bore sealing plug.
- Remove camshaft locking tools from cylinder head
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
8 1209 or equivalent
sealing compound at corners
(B) of half-moon cutouts.
Seat gasket and seal corners at VANOS unit with Three
Bond
@ 1209.
Tightening torque Cylinder head cover to cylinder head
(M6) 10 Nm (89 in-lb)
- Installation of the remaininq parts is reverse or removal, not- -
ing the following:
Change engine
011 and f~lter as descr~bed in 020 Mainte-
nance.
Reconnect battery.
To prevent damaging the engine electronic systems, install
all ground wire previously removed, including the ground
wires for the ignition coils.
Tightening torque
-
Radiator cooling fan to coolant pump 40 Nm
(30 ft-ib)
Spark plug to cylinder head
25 Nm (18 ft-ib)

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Cylinder Head and valvetrain1
Camshaft removal and installation
(M62 engine)
Camshafts, removing (M62 engine)
Special
BMW service tools should always be used to remove
and install the camshafts. Removal of the camshafts without
the special tools can result in personal injury and lor cylinder
head damage.
NOTE-
Cylinder bank 1-4 is referred to as the right cylinder bank
and is located on the passenger side. Cylinder bank 5-8 is
referred to as the left cylinder bank and is located on the driv-
er's side.
WARNING-
Allow enqine to cool before beqinninq this procedure. 1
- Disconnect negative (-) cable from battery.
CAUTION-
Prior to disconnecting the battery, read the battery discon-
nection cautions
in 001 General Cautions and Warnings.
- Dra~n coolant. See 170 Radiator and Cooling System.
Remove plastic engine covers:
Press down on locking pins (arrows) and remove top
cover.
Pry out
trlm caps (A) from covers.
Remove fasteners from beneath
trlm caps and remove
side covers.
4 Remove left and right interior ventilation filter housing (lefl
side shown):
Release locking tabs
(A) or locking strap (early models,
not shown).
Rotate duct inward (arrow) to disconnect.
- Release spring lock (6) to unloclc ventilation housing.
Disconnect electrical harness from hood switch
(C).
Release locking clip and remove ventilation filter cover (0).
Remove filter housing.
Removal of right side ventilation duct is similar.

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11 6-42
/ Cvlinder Head and Valvetrain
4 Using crankshaft center bolt, rotate engine clockwise one
complete rotation until the first cylinder is at TDC.
4 Confirm TDC position. Lobes of camshafts for cylinder head
1-4 (passengers side) should point up (arrows).
4 Remove timing chain tensioner (arrow) from right side upper
timing chain cover.
- Remove secondary air injection pipes in front of upper timing
chain covers.
- Remove left and right coolant hoses from coolant pump
housing.
- Detach dipsticlc tube from upper right timing cover,

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1 17-2
Camshaft Timing Chain
This repair group covers timing chain and VANOS repair
information for the following engines:
M52 (Single VANOS 6-cylinder engine)
M52
TU and M54 (Double VANOS engines)
M62 (Non VANOS
V-8 engine)
NOTE-
The M62 TU V-8 engine with VANOS Variable Camshaft
Timing repair information is not included.
NOTE-
See 100 Engine General for engine code and application
information.
Worn timing chains and sprocltets can lead to noisy operation
and erratic valve timing. Afaulty tensionercan also cause tim-
ing chain noises.
For specific repair procedures, refer to the appropriate repair
group:
020 Maintenance
113 Cylinder Head Removal and Installation
119 Lubrication System
121 Ignition System
170 Radiator and Cooling System
Special tools
Special BMW service tools are needed to perform the service
and repairs procedures covered in this repair group. Many of
these tools are expensive and only available through an au-
thorized BMW dealer. Be sure to read each procedure thor-
oughly before starting a job to determine which special tools
will be necessary.
In addition, Double VANOS system diagnosis can only be
carried out by using BMW specific electronic scan tools, such
as BMW
DISplus, MoDiC or equivalent.
4 Torque wrench wl flex extension
(Tool No. BMW 00
9 250)