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Cylinder Head and Valvetrain
4 Secure hydraulic lifters in lifter bores using BMW special tool
11 3 250, or remove lifters using a magnetic pick-up tool.
4 Remove camshaft bearing carrier from cylinder head.
CA UTION-
Camshaftbearing carriers must be reinstalledin their original
/ locations (E for ir;fal
NOTE-
Do not let hydraulic lifters fall out as the camshaft carrier is
removed.
Hydraulic lifters should be stored in an upright position.
Used hydraulic lifters
must be replaced into original lifter
bores.
Camshafts and lifters, installing
(M52 Engine)
Lubricate camshafts, camshaft carriers, bearing caps, hy-
draulic liflers, friction washers, splined shafts and spline hubs
with assembly lubricant before installation.
Make sure
the cranltshaft, which had been rotated approxi-
mately
30" opposite the direction of engine rotation from
TDC, is still in thatposition before lowering the
camshaffs into
position. All pistons must be out of TDC position to prevent
valve/piston interference when the camshalts are installed.
Before installing camshaft carriers, examine bearing bores
(arrows) on hydraulic lifter bores for signs of wear.
Page 194 of 1002
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116-18
Cylinder Head and Valvetrain
4 Install camshaft carriers with hydraulic lifters into cylinder
head. Note marks on carriers:
(E) for intake side and (A) for
exhaust side.
4 Center camshaft carrier on pins (arrows) at bearing posi-
tions
2 and 7.
4 Install camshafts with number 1 cylinder camshaft lobes fac-
ing each other (arrows).
CAUTION-
A minimum waiting time is required for the hydraulic lifters to
'bleed down" after installing the camshafts into the cylinder
head, before bringing the pistons to TDC. When the cam-
shafts are removed, the hydraulic
lifers can expand. This ex-
pansion can cause increased valve lift when the camshafts
are bolted down, possibly resulting in piston interference.
Camshaft Installation waiting
times
68" F (20" C) or above 4 minutes
50-68' F (1 0-20°C) 11 minutes
32-50" F (0-1 0" C) 30 minutes
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Cylinder Head and Valvetrain
NOTE-
The camshaft bearing caps are coded with a letter and a
number. For example, "A
1" is the first exhaust camshaft
bearing cap
at the front of the engine, and "El "is the intake
camshaft bearing cap at the front of the engine.
-. -
The camshafts are stamped with a code letter - "E for the
intake side and
'X" for the exhaust side.
"E is for Einlap. (German for intake) and 'XA7s for Auspuff.
(German for exhaust).
- Repeat procedure for exhaust camshaft
< Secure hydraulic lifters in lifter bores using BMW special tool
11 3 250, or remove lifters using a magnetic pick-up tool.
I CAUTION-
Used liydraulic lifters must be reinstalled in original lifter
1 bores.
4 Remove lower camshaft bearing carriers from cylinder head.
CAUTION- Camshaft bearing carriers must be reinstalled in their original
locations
(E for intalce and A for exhaust).
NOTE- Do not allow hydraulic lifters to fall out of camshaft carriers.
Hydraulic lifters should be stored in an upright position.
Camshafts and lifters, installing (M52TU and M54 engine)
Lubricate camshafts, camshaft carriers, bearing caps, hy-
draulic lifters, friction washers, splined shafts and
spline hubs
with assembly
lubricant before installation.
CAUTION-
Make sure the crankshaft, which had been rotated approxi-
mately
30" opposite the direction of engine rotation from
TDC, is
stillin thatposition before lowering the camshafts into
position. Allpistons must be out of
TDCposition to prevent
valve/piston inteiference when the carnshafis are installed.
- Lift timing chain and place exhaust cam onto exhaust cam-
shaft carriers. Place
intake camshaft on camshaft carrier.
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-- - . .- -,
Cylinder Head and Valvetrain
4 Rotate camshafts so that intalte and exhaust lobes for cylin-
der
1 face each other (arrows).
CAUJION-
A minimum waiting time is required for the hydraulic lifters to
'bleed down"after installing the camshafts into the cylinder
head, before bringing the piston to TDC. When the camshafts
are removed, the hydraulic lifters can expand. This expan-
sion can cause increased valve lift when the camshafts are
bolted down, possibly resulting in piston interference.
Place bearing caps on cams, but do not install retaining nuts.
4 Fit BMW special tool 11 3 260 (A) and 11 3 270 (B) to cylinder
head over
intalte camshaft and screw long bolts (arrows)
into spark plug threads.
CA UTION-
Do not overtighten bolts into spark plug holes.
< Turn eccentric shaft of special tool to pretension bearing
caps. Install and torque nuts on intake camshaft bearing
caps.
Tightening torque Camshaft bearing cap
to cylinder head (M7) 14 Nm (10 it-ib)
- Release tension on eccentric shaft and remove BMW special
tools
11 3 2601270.
- Repeat procedure for exhaust camshaft.
NOTE-
Observe waiting time for lifter bleed down before continuing
with camshaff installation.
Crankshaft
I valve timing waiting times
68°F (20°C) and higher 5 minutes
50-6S°F(10-20°C) 15 minutes
32-50DF(O-10°C) 30 minutes
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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
1 VANOS I 4 When engine is started, camshafts are in deactivated
camshaft
retarded Engine I i oil supply
position:
. lntalte camshaft is held in RETARDED position by oil
pressure.
Exhaust camshaft is held in ADVANCED position by
preload spring and oil pressure.
VANOS
Piston out
ECM Piston in Within 2
- 5
seconds (50 engine revolutions), the ECM begins
monitoring and controlling camshaft positions.
The Double VANOS system allows full variability of camshaft
timing up to the limits of the system. When the ECM detects
that the camshafts are in optimum position, the solenoids are
modulated at approximately 100
- 220 Hz to maintain oil pres-
sure on both sides of the actuator pistons to maintain timing.
In models with DME
MS 43.0 (model year2001 and newer),
the engine control module (ECM) detects camshaft position
before the engine starts, thereby adjusting camshaft timing
immediately upon start-up.
NOTE-
. VANOS system troubleshooting and diagnostics is best
accomplished using a scan tool.
. Diagnostic Trouble Codes (DTCs) pertaining to the
VANOS system are listed
in the following table. See also
OED On-Board Diagnostics.
Elevated oil temperatures can cause VANOS to deactivate.
Oil that is too thick (high viscosity) may cause
a DTC to be
set
in the ECM. If VANOS is deactivated (limp-home
mode), there will be a noticeable loss of power.
VANOS fault codes
BMW code P-code Fault description
19
PI529 VANOS solenoid valve activation,
exhaust
21
PI525 VANOS solenoid valve activation,
intake
103
PI519 VANOS faulty reference value
intake
104
PI520 VANOS faulty reference value
exhaust
105
PI522 VANOS stuck (Bank I) intake
106
PI523 VANOS stuck (Bank 2) exhaust
Page 272 of 1002
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1 17-36
Camshaft Timing Chain
1 Double VANOS control unit
1. BoltM6
2. Exhaust camshaft position
sensor
3. Sealing ring
4. Camshaft end sealing plug
-tighten to 50 Nm (37 ft-lb)
5. Camshaft seal cap
6. VANOS hydraulic piston set
screw -CAUTION: left hand
thread -tighten to
10 Nm
(89 in-lb)
7. Nut M7 -tighten to
14 Nm
(1 0 ft-lb)
8. Engine lifting hook
9. Stud M7
10. Nut
M6 -tighten to 10 Nm
(89 lb-in)
11. Gasket
12. Cylinder head
13. Sealing ring
14. Intake camshaft sensol
15. Bolt M6
16. VANOS control unit
17. Copper sealing ring
18. VANOS oil feed line
19. Banjo bolt -tighten to 32 Nm
(24ft-lb)
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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) -