2005 BMW 745i sensor

Downloaded from www.Manualslib.com manuals search engine Cylinder Head Gaskets
The cylinder head gasket is a multi-layer steel
gasket with a rubber coating. This type of gas-
ket has previously been used on other engines.
The B44 head gasket has a 6 mm hole in a flap
on the outlet side of the cylinder head gasket.
The cylinder head bolts for the N62 engine are
M10x160 necked-down “stretch” bolts.
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The lower part of the timing chain housing is
bolted to the cylinder head using two M8x45
bolts.
Camshafts
The camshafts are made from chilled cast iron
and are hollowed to reduce weight. The cam-
shafts are weighted with counterbalances for
equalizing imbalances in the valve gear.
1. Camshaft sensor wheels (sintered metal)
2. Thrust bearing area with oil ducts for the
VANOS units
N No
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22
N62 Engine
42-02-23
42-02-22
42-02-24

Downloaded from www.Manualslib.com manuals search engine Principle of Operation
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This combi-
nation of abilities allows the ECM to control when the intake valves are opened and closed,
and also the opening lift. The intake air flow is set by adjusting the valve lift while the throt-
tle valve is fully opened. This improves cylinder filling still further and reduces fuel con-
sumption.
Each cylinder head in the N62 engine has a Valvetronic assembly. This Valvetronic assem-
bly consists of a bridge support with eccentric shaft, intermediate levers with retaining
springs, drag lever and the intake camshaft.
In addition, the following components belong to
the Valvetronic system:
• A Valvetronic motor for each cylinder head
• A Valvetronic control module
• A Valvetronic sensor for each cylinder head
The intake valve lift can be adjusted to anywhere between 0.3 mm and 9.85 mm.
The cylinder heads are precision manufactured together to ensure precise flow rate and
uniform distribution. The valve gear components on the intake side are precisely matched
together to the tightest limits.
The bridge support, lower eccentric shaft and inlet camshaft bearings are matched togeth-
er in the cylinder head once it is assembled. If the bridge support or the lower bearings are
damaged, the entire assembly must be replaced.
N No
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25
N62 Engines
42-02-30

Downloaded from www.Manualslib.com manuals search engine 27
N62 Engine
Eccentric Shafts
The eccentric shafts (one per cylinder head) are driven by the
Valvetronic motors and are supported by four caged needle
bearing assemblies for a smooth rotation.
To assist in maintaining the set positions and counter the
valve train torque, a torque compensation spring is mounted
on the end of the shaft for tension.
Magnets are fitted in the (removable) magnetic wheel at the
end of the eccentric shaft. Together with the position sensor,
the Valvetronic Control Module determines the exact shaft
position. The eccentric shaft sensor is mounted through the
cylinder head cover (one per cylinder head) at the back.
The magnetic wheel is secured to the shaft by a bolt and is
indexed by a tab (arrow) to prevent incorrect installation.
Intermediate Lever and Roller Finger
The intermediate lever is positioned further (minimum valve
opening) or closer (maximum valve opening) to the camshaft
by the the progressive “lobe” on the eccentric shaft as it is
rotated. This offers a variable ratio effect for valve actuation.
The roller finger is used to actuate the intake valve.
The intermediate levers and roller fingers are matched (by
classification) to ensure uniform valve lift.
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42-02-3643-02-32
43-02-38
43-02-33

Downloaded from www.Manualslib.com manuals search engine 30
N62 Engine
Camshaft Sensors
The cam shaft sensors (Hall effect) are mounted through the cylinder head cover. There are
two sensors per cylinder head to monitor the intake and exhaust camshaft positions.
The sensors monitor the impulse wheels
attached to the ends of the camshafts.
Solenoid Valves
The VANOS solenoid valves are mounted through the upper timing case front cover. There
are two solenoids per cylinder head to control the oil flow to the camshaft ports for the
intake and exhaust VANOS units.
The 4/3 way proportional solenoid valve is acti-
vated by the ECM to direct oil flow. The sole-
noid valve is sealed to the front cover by a radi-
al seal and secured by a retaining plate.
N No
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s:
:

42-02-48 Camshaft Sensors
1. Valvetronic Position Sensor
2. Intake Camshaft Position Sensor
3. Exhaust Camshaft Position Sensor
42-02-42

Downloaded from www.Manualslib.com manuals search engine 35
N62 Engine
Chain Drive
The camshafts are driven by a toothed chain, one for each cylinder bank. The oil pump is
driven by a separate roller chain.
1. Sensor wheels for the camshaft position sensor, cylinder bank 1-4
2. Tensioner Rail, Cylinder 5-8
3. Chain Tensioner, Cylinder Bank 5-8
4. Sensor Wheel for the camshaft position sensor, cylinder bank 5-8
5. Upper timing chain guide with integrated oil jet
6. Guide rail
7. Sprocket for Oil Pump Drive
8. Timing case lower section
9. Tensioning rail, cylinder bank 1-4
10. Solenoid Valve, VANOS exhaust camshaft
11. Solenoid Valve, VANOS intake camshaft
12. Upper Timing Chain Cover
13. Chain Tensioner, Cylinder Bank 1-4
14. VANOS exhaust camshaft Bank 1-4
15. Upper Timing Chain guide with integrated oil jet
16. VANOS intake camshaft 1-4Chain Drive
43-02-50

Downloaded from www.Manualslib.com manuals search engine 38
N62 Engine
Cooling System
Coolant Circuit - 14 Liter Coolant Capacity
42-02-56
Cooling System (Circuit Flow)
1. Cylinder Head Bank 5-8 12. Radiator
2. Coolant Supply (heater core) 13. Radiator Partition (low temp section)
3. Water valve with electric water pump 14. Temperature Sensor
4. Cylinder Head Gasket 15. Water Pump
5. Coolant Supply Line 16. Radiator Return Flow
6. Cylinder Head Ventilation Lines 17. Radiator Ventilation Line
7. Hole (crankcase venting system) 18. Expansion Tank
8. Transmission oil lines 19. Thermostat
9. Oil/water heater exchanger for automatic transmission 20. Cylinder Head Bank 1-4
10. Thermostat for transmission oil heat exchanger 21. Vehicle Heater
11. Alternator Housing 22. Radiator (High Temperature Area)

Downloaded from www.Manualslib.com manuals search engine 40
N62 Engine
The coolant flows to the rear of the engine block, from there through the side channels to
the cylinder walls and then into the cylinder heads (lower left picture). The cast aluminum
cover at the rear of the engine block (with sealing bead) is shown on the lower right.
Water Pump/Thermostat Housing
The water pump is combined with the thermostat housing and is bolted to the timing case
lower section.
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The impeller is made from reinforced plastic.
42-02-59
Water Pump / Thermostat Housing
1. Map-controlled themostat (radiator cool return flow).
2. Electrical connection for Thermostat Heating element.
3. Thermostat Mixing Chamber
4. Temperature Sensor (hot coolant from engine)
5. Radiator in-flow (hot coolant from engine)
6. Heat exchanger (transmission oil return flow)
7. Leakage Chamber (evaporation space)
8. Alternator in-flow (cool supply)
9. Water Pump
10. Expansion Tank Connection

Downloaded from www.Manualslib.com manuals search engine 42
N62 Engine
Map-controlled Thermostat
The map-controlled thermostat allows the engine to be cooled relevant to operating con-
ditions. This reduces fuel consumption by approximately 1-6%. The electrical connections,
the design and the map-controlled thermostat response have been enhanced. The map-
controlled thermostat function is the same as previous engines (M62).
Cooling Module
The cooling module contains the following main cooling system components:
• Cooling radiator
• Air conditioning condenser
• Transmission oil/water heat exchanger
• Hydraulic fluid radiator
• Engine oil radiator
• Main electric fan
• Fan shroud for viscous coupling fan
All the components (with the exception of the transmission oil radiator) can be removed for
repairs without disassembling any other coolant circuit. All connections have been fitted
with the quick-release coupling which are used in current models.
Maped-Controlled Thermostat
1. Radiator Return Flow To Thermostat
2. Connection for Thermostat Heating Element
3. Temperature Sensor
4. Radiator in-flow (hot coolant from engine)