1999 BMW 525i replace timing chain

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Camshaft Timing chain1
Tap locating dowels into cover until they protrude 2 to 3 mm
from sealing surface.
- Using new gaskets, install lower timing chain cover:
Tap cover into position to engage dowels.
Install timing chain cover fasteners and tighten to
5 Nm (44
in-lb).
Drive dowels in flush to front of cover.
. Tighten cover mounting bolts alternately and in stages.
Install cylinder head to timing chain cover fasteners and
tighten.
Tightening torques Lower timing chain cover to block
M7 15 Nm (1 1 ft-lb)
ME 20 Nm (15 it-lb)
- Replace front crankshaft radial seal. See Crankshaft oil
seal, front, replacing
(M52 engine).
Install engine oil pan using
a new gasket. See 119 Lubrica-
tion System.
Mount primary timing chain sprocket to primary
cha~n so that
arrow on sprocket faces up. Mount sprocket to camshafl so
that tapped holes in camshaft are on left side of elongated
holes in sprocket.
4 Install adjustable timing chain tensioner (BMW special tool
11 4 220). Thread tool in finger tight until slack is removed
from chain.
NOTE-
BMW special tool 11 4 220 is an adjustable timing chain ten-
sioner that simulates the function of the hydraulic tensioner.
- Check that elongated holes in primary sprocket are centered
to bolt holes in camshafl and chain is free of slack.
- Install secondary timing chain guide and secondary chain
tensioner. Tighten mounting bolts (tensioner remains
locited
down).
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Camshaft Timing Chain
VANOS control unit, removing
(M52 TU and M54 engines)
This procedure includes removal of the Double VANOS con-
trol unit.
NOTE-
If the Double VANOS control unit is being replaced, camshaft
timing must be checked. This procedure requires multiple
special tools. Be sure to read the procedures through before
beginning the repair.
- Working inside luggage compartment, disconnect negative
(-) battery cable.
Prior to disconnecting the
batteg read the battery discon-
nection cautions given in
001 General Cautions and
Remove engine cooling fan assembly. See 170 Radiator
and Cooling System.
Remove engine trim covers.
Pry out plastic trim caps (arrows).
Remove cover fasteners, oil filler cap, and covers.
Remove ignition coils:
Disconnect ignition coil electrical harness connectors.
Remove coil mounting fasteners and coils.
NOTE-
Make note of ignition coil ground strap locations.
Remove spark plugs,

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Camshaft Timing Chain
4 Remove VANOS unit:
Remove fasteners from engine support eye.
Remove VANOS mounting nuts (arrows) from cylinder
head. Slide VANOS control unit and metal gasltet off.
NOJE-
The VANOS control unit will contain residual oil. Place
shop towels beneath adjustment unit when removing.
If the VANOS control unit is replaced, or if repair operations
are completed that may change camshaft timing, the cam-
shaft timing must be checked as described in VANOS tim-
ing,
checlcing and adjusting (M52 JU and M54
engines).
CAUJION-
Do not crank the engine with VANOS unit removed.
Piston/valve interference may result.
VANOS control unit, installing
(M52 TU and M54 engines)
< Clean contact edges of cylinder head face and double
VANOS control unit and apply a thin coat of sealing com-
pound (Three Bond
1209 8 or equivalent) to surfaces.
I CAUJION-
. Make sure all gaskel material is removed from lace of
cyl~nder head. Clean sealing lace and keep lree of oil.
Checklocating dowel (A) and dowelsleeve (B) at top of
cylinder head for damage or incorrect installation.
NO
JE -
If the Double VANOS control unit is beino reolaced. be -.
sure to check and adjust camshaft timing, see VA NOS
timing, checking and adjusting (M52 JU and M54 en-
gines).
* If work being carried out has no effect on camshaft timing,
it is not necessary to recheck the timing. It is recommend-
ed, however, that the VANOS operation be checked using
a compatible scan tool once the engine is running.

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I Camshaft Timing Chain
- Using new gasket, install VANOS control unit to cylinde~
head.
Reinstall engine support eye.
Tightening torques VANOS control unit to cylinder head
M6 nut 10 Nm (89 in-lb)
M7 nut 14 Nm (10 ft-ib)
4 Insert and tighten VANOS hydraulic piston set screws on
intake and exhaust camshafts.
CAUTIOI\C
Set screws have left hand thread Tighten counterclocltwise.
Tightening torque
Hydraulic piston
to splined shaft 10 Nm (89 in-lb)
(set screw)
4 Replace sealing caps inside VANOS control unit with BMW
special tool 11 6 170, or short flat nosed pliers.
Insert and secure VANOS sealing plugs (arrows), using new
sealing O-rings.
Tightening torque Sealing plug to VANOS control unit 50 Nm (37
it-lb)
Remove compressed air fitting from VANOS control unit
Fit VANOS oil line banjo bolt with new seals. Attach oil line to
VANOS control unit.
Tightening torque Oil line to VANOS control unit (banjo bolt) 32
Nm (24
it-lb) -

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Camshaft Timing Chain
- Connect electrical harness connectors to camshaft position
sensors and VANOS solenoid valves.
- Remove BMW special locking tools from rear of cylinder
head.
- Remove cranltshaft locking tool and replace sealing plug.
Install intake camshaft baffle and cylinder head cover.
Checlc 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
(B) of half-moon cutouts.
Similarly, seat gasket and
seal corners in front of cylinder
head, at VANOS control unit.
Tightening torque
Cylinder head cover to cylinder head
(M6) 10 Nm (89 in-lb)
- Remainder of installation is reverse of removal.
Tightening torques
Radiator fan (viscous clutch) to
coolant pump 40
Nm (30 ft-lb)
Spark plug to cylinder head
25 Nrn (18 ft-lb)
VANOS timing, checking and adjusting
(M52 TU and M54 engines)
Use this procedure to check and, if necessary, adjust cam-
shaft timing. This procedure assumes that the cylinder head
cover and intake
camshaft plastic baffle have been removed.
Also, be sure the cooling fan and the spark plugs have been
removed.
Remove primary camshaft chain tensioner cylinder
(arrow).
~~ ~ ~~ ~--~
CA UTlOAC
Primary camshaft chain tensioning piston is under spring
pressure.

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~ ~~ ~
I Camshaft Timing Chain I --
lnstall crankshaft holding tool (BMW special tool 11 8 190/11
8 200). Make sure cut outs in tool engages openings in
damper assembly. While counterholding crankshaft with
special tool, remove crankshaft center bolt (A).
CAUTION-
Do not use flywheel locking tool to hold crankshaft stationary
NOTE-
The crankshaft hub centerbolt is tightened to a torque of 410
Nm (300 ft-lb).
4 Install crankshaft damper puller (BMW special tool 11 8 210)
to 11 8 200. and (A) remove damper from crankshaft.
The crankshaft must not be allowed to rotate when the timing
chains are loosened or removed. The pistons can contact the
valves. Use appropriate crankshaft holding tool when loosen-
ing crankshaft hub center bolt.
Using a drift of less than
5 mm diameter, drive two locating
dowels in left and right sides of lower timing
cham cover to-
ward engine. Remove cover mounting bolts
(arrows) and
carefully lift cover off.
CA
UTION-
* Use care when removing the cover from the cylinder heao
gasket. If the cover is stuck, use a sharp
knife to separate
it from the headgasket.
If cylinder liead gasket Is damaged, remove cylinder
head and replace head gasket. See
113 Cylinder
head and valvetrain.
NOTE-
- The chain cover can be removed with the coolant pump in-
stalled.
Use care when removing the cover from the coolant pipe
at rear.
- Push primary chain tensioner guide rail aside and remove
chain.

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... -.
rpp- --- Camshaft Timing Chain1
Timing chains, installing
(M52 TU and M54 engines)
CAUTIOI\C
The procedure outlined below assumes that the camshaits
are lockedin the
TDC installation position with speciallocling
tools as shown earliel:
- inspect timing chain sprockets. Inspect guide rail and ten-
sioner rail for damage. Replace any part that is worn
or dam-
aged.
NOTE-
If any sprockets are being replaced due to wear, the chain
should also be replaced.
4 Primary timing chain assembly
1. Primary chain tensioner
2. Chain tensioner rail
3. Cranltshaft sprocket
4. Exhaust camshaft sprocket
5. Primary chain
6. Anchor bolt
7. Guide rail
8. Anchor bolt
9. Woodruff key
- Install primary timing chain to crankshaft sprocltet and hang
upper end from exhaust camshaft.
- If necessary, replace crankshaft radial seal in cover. See
Crankshaft oil seal, replacing (M52 TU and M54 engines).

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I Camshaft Timina Chain
/ Cylinders 5-8
Timing chains, installing
(M62 engine to 911 998)
4 The procedure outlined below assumes that the camshafts
are locked in the TDC installation position with special lock-
ing tools as shown earlier.
4 lnspect timing chain sprocltets and chain. Inspect guide rail
and tensioner rail
(arrows) for grooves caused by chain con-
tact. Replace any part that is worn or damaged.
NOTE-
If any sprocl(ets are being replaced due to wear, the chain
should also be replaced.
If the crankshaft sprocket requires
replacement, the oil pump
drive sprocket and chain must be
removed. See
119 Lubrication System for oilpump removal
information.
- If removed, reinstall timing chain tensioning rail, reversing
rail, and guide rail.
If tensioning rail was removed, replace O-ring at tensioning
rail oil guide.
Tightening torque Reversing rail
to engine block 14 Nrn (10 n-lb)
4 lnstall timing chain and intalte sprocket to intake camshaft on
left cylinder head. Center bores of camshaft flange in sprock-
et mounting slots. Install two mounting bolts finger tight.