low oil pressure BMW 545i 2002 E60 N62B44 Engine Workshop Manual

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N62 Engine
N62 ENGINE
Model: E65 - 745i / E66 - 745Li
Engine: N62B44
Production Date: 11/2001 - E65, 01/2002 - E66
Objectives of The Module
After Completing this module, you will be able to:
• Describe the two stage oil supply.
• Distinguish the difference between the left and right drive chain tensioning assem-
blies.
• Explain the Bi-VANOS operation.
• Understand the function of the Variable intake manifold.
• Explain the cooling circuit flow.
• List what chamber A and chamber B is used for in the Bi-VANOS system.
• Identify the Secondary air components.
• Explain how the initial VANOS position is retained when oil pressure is not present.
• List the proper drive belt removal procedure.
• Describe the throttle valve functions.
• Identify the N62B44 designation.

Downloaded from www.Manualslib.com manuals search engine Crankcase Venting System
The crankcase vapors (a result of combustion blow-by gasses) are led out of the crank-
case and back into the combustion chamber via the intake manifold. The blow-by gasses
contain droplets of oil which must be separated. The oil is returned to the sump while the
blow-by gasses are led into the intake pipe for combustion.
The engine performance is affected by the introduction of crankcase vapors into the com-
bustion process, particularly in idle speed ranges. This influence is monitored by lambda
regulation.
The crankcase vapors are carried from the crankcase and into the cylinder head covers
through labyrinth separators (one per cylinder head). The oil which accumulates on the
walls of the labyrinth separators flows into the cylinder head via a siphon and from there
back to the sump.
The remaining vapors are passed to the engine for combustion via the pressure control
valve (5) in the intake manifold. One labyrinth separator with a pressure control valve is inte-
grated in each of the two cylinder head covers.
The throttle valve is controlled so that there is always a 50 mbar vacuum in the intake man-
ifold. The pressure control valve regulates the crankcase pressure to a low 0-30 mbar.
12
N62 Engine
43-02-12 Cylinder Head Cover
1-4. Opening for Spark Plugs
5. Pressure Control Valve
6. Opening Valvetronic Motor
7. Opening Valvetronic Sensor
Connector
8. Camshaft Sensor

Downloaded from www.Manualslib.com manuals search engine Cylinder Heads
The two N62 cylinder heads are a new development from BMW. They are fitted with the
Valvetronic system. The secondary air ducts for subsequent exhaust gas treatment are
integrated in the cylinder heads. The cylinder heads are cooled by the “cross-flow” princi-
ple.
The inlet camshaft and the Valvetronic eccentric shaft are jointly guided by a bridge sup-
port. The cylinder heads are made from aluminum and are manufactured using gravity die-
casting. The upper timing chain housing is now an integral part of the cylinder head.
20
N62 Engine
Cylinder Head
1. Cylinder Head for Cylinder Bank 1-4 7. Mounting VANOS Intake Solenoid
2. Cylinder Head for Cylinder Bank 5-8 8. Mounting VANOS Outlet Solenoid
3. Upper Timing Chain Guide with Oil Jet 9. Oil Pressure Switch
4. Mounting for VANOS Intake Solenoid 10. Chain Tensioner Mount
5. Mounting for VANOS Outlet Solenoid 11. Upper Timing Chain Guide with Oil Jet
6. Chain Tensioner Mount43-02-20

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N62 Engine
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When oil pressure is applied to chamber A, the blades are forced away from the VANOS
housing (counterclockwise). The blades are keyed into the hub which results in the hub
position being rotated in relation to the housing (with sprocket). The hub is secured to the
camshaft which changes the camshaft to sprocket relationship (timing).
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procedure together with the pressure progres-
sion based on the VANOS unit for the exhaust camshafts.
During this adjustment chamber B is open (through the solenoid) to allow the oil to drain
back through the cylinder head (internal reservoir).
Hydraulic Actuation - Chamber A
1. Front View of Vanos Unit 5. Engine Oil Pump
2. Side View of Vanos Unit 6. Supplied Oil from Pump (Switched Through Solenoid)
3. Camshaft Oil Port (Chamber B) 7. Supplied Oil Pressure (From Engine Oil Pump)
4. Solenoid Valve43-02-45

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N62 Engine
When the solenoid valve switches over, oil pressure is applied to chamber B. This forces
the blades (and hub) in a clockwise direction back to the initial position, again changing the
camshaft timing.
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procedure together with the pressure progression
based on the VANOS unit for the exhaust camshafts.
During this adjustment chamber A is open (through the solenoid) to allow the oil to drain
back through the cylinder head (internal reservoir).
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42-02-44 Hydraulic Actuation - Chamber B
1. Front View of VANOS Unit 5. Engine Oil Pump
2. Side View of VANOS Unit 6. Oil Return (Switched through Solenoid)
3. Camshaft Oil Port (Chamber B) 7. Supplied Oil Pressure (From Engine Oil Pump)
4. Solenoid Valve

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N62 Engine
Tensioning Rail Bearing Pin
The bearing pin for the cylinder bank 1-4 drive
chain tensioning rail is hollowed. There is a ball
(check) valve in the bearing pin. The valve
opens at an oil pressure of 1 bar and allows
engine oil to flow to the tensioning rail via a port
(1).
Chain Tensioner (cylinder bank 5-8)
An oil jet has been fitted to lubricate the cylinder bank
5-8 drive chain. There is a valve in the oil jet which
opens at a pressure of 1 bar and supplies the drive
chain with engine oil.
N No
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Refer to the Repair Instructions when using the
Special Tools shown below to adjust the camshaft tim-
ing.
42-02-53
42-02-54 Tensioning Rail Bearing Pin
1. Engine Oil Port to Tensioning Rail
2. Ball (check) Valve
3. Bearing Pin
4. Sealing Rings for Sealing the Tensioning Rail
Chain Tensioner
1. Chain Tensioner
2. Tensioning Rail
3. Oil Jet
42-02-7842-02-79

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N62 Engine
Cooling Radiator
The radiator is made from aluminum and is divided into a high-temperature section and a
low-temperature section by a partition wall (see coolant circuit diagram). The coolant first
flows into the high-temperature section and then back to the engine, cooled.
Some of the coolant flows through an opening in the radiator partition wall to the low-tem-
perature section where it is cooled further. The coolant then flows from the low-tempera-
ture section (when the ÖWT thermostat is open) into the oil/coolant heat exchanger.
Coolant Expansion Tank
The expansion tank is mounted on the right hand wheel housing (engine compartment).
N No
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:
The expansion tank should never be filled above the Max marking. Excess coolant is
expelled by the pressure relief valve in the cap as it heats up. Avoid overfilling the expan-
sion tank because the cooling circuit design ensures very good “self bleeding”.
Cooling Components
1. Cooling Radiator 4. Engine oil/air heat exchanger connection
2. Expansion Tank (hot countries only)
3. Water Pump 5. Transmission oil/coolant heat exchanger

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N62 Engine
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Oil Pressure Switch
The oil pressure switch is located on the side in the bank 1-4 cylinder head.
Oil Pump
The oil pump is mounted at an angle to the crankshaft bearing cap and is driven by the
crankshaft using a roller chain. The oil pump is a two-stage gear oil pump with two paral-
lel switched gear clusters.
The two pair of gear clusters are stacked one
behind the other and work in two stages.
Stage two (both pump supply circuits) is only
active in the lower engine speed range up to
approx. 2,000 rpm to provide sufficient oil pres-
sure for the VANOS at high oil temperatures.
Stage two is deactivated hydraulically at a pres-
sure of 2 bar.
42-02-73
42-02-75
42-02-76 Oil Pump
1. Drive Shaft
2. Mounting Points
3. Oil Filter
4. Pressure Relief Valve (over 15 Bar)
5. Control Valve (Pump Stage/Pressure Control)
6. Oil supply from the oil pump to the engine
7. Oil pressure control tube from the engine to
the control valve.

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N62 Engine
Oil Filter
The canister type oil filter (3) is located under the
engine by the oil sump. The support for the oil
filter is integrated in the rear oil pump cover.
The oil filter housing (2 with o-ring) is threaded
into the rear of the oil pump cover through an
opening in the oil sump.
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The filter element support dome contains an over pressure relief valve. If the filter element
is blocked, this valve bypasses unfiltered engine oil around the element to the supply lubri-
cation to the engine.
Pressure Control
The oil pressure control valve in the oil pump has two functions:
1. Deactivates stage two oil pump circuit above 2 bar. Stage two is only active in the
lower speed range. This is to ensure that there is always sufficient oil pressure for
the VANOS units even at high oil temperatures and low speeds. The oil pump power
consumption is reduced by deactivating stage two.
2. Monitoring the required oil pressure for the engine. The piston in the control valve is
moved by a spring against the engine control pressure which is returning from the
engine. This means that precise monitoring of the actual engine oil pressure is pos-
sible.
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42-02-77

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N62 Engine
Oil Cooling (if equipped)
An oil cooler is used in hot countries. The oil cooler is located in front of the radiator above
the A/C condenser. The engine oil flows from the oil pump through a channel in the
crankcase to a connection on the generator support. The generator support has an oil ther-
mostat. A wax element in the oil thermostat continuously opens the inflow to the oil cooler
when the oil temperature is between 100 ºC to 130 ºC.
Some of the engine oil always flows past the oil thermostat and through the engine with-
out being cooled, even when the oil thermostat is fully open. This ensures a minimum
amount of oil is supplied when the cooler is faulty. A modified generator support, without
connections for the oil thermostat, is fitted to vehicles which do not have an oil cooler.
Technical Data - Lubrication System
The recommended oil is BMW High Performance 5W-30 Synthetic Oil
* P/N 07 51 0 017 866
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8.0 Filling Capacity for Service with Oil Filter Change


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1.0 Minimum Oil Pressure at 20ºC

4.0 - 8.0 Bar Maximum Oil Pressure at 20ºC


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9-12 I/Min At Idle Speed (700 rpm) at 20ºC

50-55 I/Min At Maximum Engine Speed (6500 rpm) and 20ºC