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Camshaft Timing chain1
VANOS control unit, installing (M52 engine)
CAUTION-
Incorrect installation of the VANOS control unit may result in
damage to the engine.
- Make sure camshafts and crankshaft are loclted in TDC po-
sition with BMW special tools as described during VANOS
removal.
< Rotate exhaust camshaft sprocket clocltwise (as viewed from
front of engine) using BMW special tool
11 5 490, until detent
position stop is reached.
4 Apply a small amount of liquid gasket sealer (Three Bond
1209
8 or equivalent) to VANOS housing alignment dowels
on front of cylinder head. Install a new
gasket.
< Push VANOS piston gear cup (arrow) into VANOS housing
until it bottoms out. Position VANOS control unit in front of
camshafts, but do not engage splines on gear cup.
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Camshaft Timing Chain
4 Disconnect VANOS electrical harness connector (A) and oil
line fitting
(B) from VANOS control unit.
NOTE-
Wrap the VANOS oil line fitting with a shop rag to absorb
leaking oil.
Disconnect cranltcase breather by squeezing at arrows.
- Remove cylinder cover mounting fasteners and remove
cylinder head cover.
NOTE-
The cylinder head cover mounting bolt insulators andgas-
lets should be reinstalled in their original positions. Make
note of their arrangement during removal.
4 Remove oil baffle cover from intake camshaft
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-
Camshaft Timing Chain -. -
Measure gap (B) between secondary timing chain tensioner
and intake camshaft sensor wheel. Make note of distance.
To determine VANOS control travel:
Distance
I3 - distance A = a minimum of 8.5 mm
CAUTION-
If the adjustment travel is less than 8.5 mm the VANOS ad-
justment unit must be removed and readjusted. See
VANOS
control unit, removing (M52 engine)
and VANOS con-
trol unit, installing
(M52 engine).
Remove special tools:
Cranltshaft locking tool.
Camshaft
loclting tool set.
Air fitting.
* VANOS cable adaptor.
- Install VANOS oil line with new seal
- Install oil baffle cover above intake camshaft.
- Install cylinder head cover mounting studs to rear of head.
- Install cylinder head cover,
Tightening
torques
Cylinder head cover 10 Nrn (89 in-lb)
VANOS oil line
32 Nm (24 R-lb)
VANOS solenoid to control unit 30 Nrn (22 ft-lb)
- Installation of remaining parts is reverse of removal.
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Camshaft Timing Chain Timing chains, removing
(M52 engine)
Camshaft timing chain removal on M52 engines requires en-
gine oil pan removal.
Special
BMW sewice tools are needed for timing chain re-
moval and installation procedures. The special tools assure
propertiming of thevalvetrain. Precise marks to
setthe timing
on the camshafts are not provided for reassembly. Read the
procedures through before beginning the job.
NOTE-
If the camshafts are not properly timed, the pistons can con-
tact the valves.
- Remove VANOS control unit. See VANOS control unit, re-
moving (M52 engine).
- Remove radiator cooling fan and shroud. See 170 Radiator
and Cooling System.
- Drain cooling system. See 170 Radiator and Cooling Sys-
tem.
- Remove coolant hoses from thermostat housing and remove
thermostat housing from front of cylinder head.
- Loosen bolts for coolant pump pulley.
- Remove drive belts for alternator and AIC compressor. See
020 Maintenance.
- Remove coolant pump pulley.
Remove drive belt tensioner mounting bolts (arrows) and re-
move tensioner from front of engine.
- Remove engine speed sensor from lower timing chain cover.
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4 With crankshaft at TDC position, remove vibration damper
bolts (arrows) and remove vibration damper.
< Mount crankshaft holding tool (BMW special tool 11 2 150
and
11 2 410) to crankshaft hub. Counter hold crankshaft and
loosen crankshaft hub retaining bolt.
Crankshaft hub retaining bolt is torqued to
410 Nm (300 ft-lb).
Do not use flywheel
locliing tool to hold cranl(shait stationary
to loosen or tighten crankshaft hub center bolt. Use only the
special tools specified, or equivalent hub holding tool.
- Remove crankshaft hub.
- Remove cylinder cover mounting fasteners and remove cyl-
inder head cover.
NOTE-
The cylinder head cover mounting bolt insulators and gas-
lets should be reinstalled in their original positions. Make
note of their arrangement during removal.
- Drain engine oil, remove oil pan. See 119 Lubrication Sys-
tem.
Remove primary timing chain tensioner (arrow).
CAUTION-
Timing chain tensioner is under spring tension. I
- Remove VANOS control unit. See VANOS control unit, re-
moving
(M52 engine).
- Remove fasteners from intake and exhaust camshaft
sprocket.
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-- Camshaft Timing Chain -- -
Tightening torque
Vibration damper hub to crankshaft
410 Nm (300 ft-lb)
4 Install cranltshaft hub and vibration damper while aligning
locating hole (arrow) in damper with dowel pin in hub.
Tightening torque
Vibration damper and
pulley to
cranltshaft hub
22 Nm (17 ft-lb)
- Turn engine over by hand in direction of rotation at least two
full rotations. Reinstall camshaft and crankshaft locking
toois
to recheck engine timing. Remove locking tools if no faults
are found.
- Remove BMW special tool 11 3 390 (dummy tensioner) from
side of cyiinder head.
- Install primary chain tensionerso that cutout in tensioner pis-
ton engages chain rail.
Tightening torque
Timing chain tensioner to tensioner sleeve
70 Nm (52 ft-ib)
- Install cylinder head cover mounting studs, camshaft cover,
and cylinder head cover.
Tightening torque Cylinder head cover to cyiinder head
M6 nut 10 Nm (89 in-lb)
MB bolt 22 Nm (17 ft-lb)
- installation of remaining parts is reverse of removal, noting
the following:
When installing thermostat, make sure arrow or vent hole
faces up, if applicable.
Refill cooling system as described in
170 Radiator and
Cooling System.
Fill engine with oil and install new
oil filter as described in
020 Maintenance.
Tightening torque Upper timing chain cover to cylinder head
M6 nut 10 Nm (89 in-lb)
MB bolt 22 Nm (17 ft-lb)
VANOS oil supply pipe to VANOS control
unit banjo bolt
32 Nm (24 ft-ib)
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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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-- - -- - -- Camshaft Timing chain1
- Remove camshaft locking tools from rear of camshafts
- Remove BMW special tool 11 4 220 (adjustable primary
chain tensioner). Reinstall primary chain tensioner.
Tightening torque Primary chain tensioner to cylinder head
70
Nm (52 it-lb)
- Remove crankshaft locking tool from transmission bellhous-
ing. Reinstall sealing plug.
- Remove VANOS setup bracket from front of cylinder head
- lnstall VANOS control unit as described earlier in this group.
- Remove compressed air fitting (BMW special tool 11 3 450)
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 H-lb)
- Remainder of installation is reverse of removal, noting the fol-
lowing:
lnstall spark plugs.
* lnstall intake camshaft plastic baffle prior to installing cylin-
der head cover. lnstall ignition coil packs and connect elec-
trical harness connectors.
Install radiator cooling fan.
- lnstall air filter housing and top engine cover.
Tightening torque Radiator cooling fan
(VISCOUS clutch) to 40 Nm (30 ft-lb)
coolant pump
Cyitnder head cover to cylinder head 10 Nm (89 in-lb)
Sparlc plug to cylinder head 25 Nm (18 ft-lb)