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Home >> BMW >> 2021 >> 840i 2D Convertible >> Repair and Diagnosis >> Engine Mechanical >> Mechanical >> Cylinder Head -- Repair (G14, G15, & G16) (5 Of 7) >> 11 12 Cylinder Head >> 11 12 156 Disassembling and assembling cylinder head, right (M850i xDrive convertible) >> Disassembling and assembling cylinder head, right

Disassembling and assembling cylinder head, right

WARNING: Hot surfaces. 
Risk of burning! 
  • Perform all work only on components that have cooled down.
WARNING: Vehicle may slip off the vehicle hoist if the vehicle hoist is handled incorrectly. 
Danger! Immobilization period-threatening injuries! 
WARNING: Working on 12 V electrical system. 
Risk of short circuits! Risk of fire! 
  • Make sure that there is no charger  connected to the jump start terminal in the engine compartment.
  • Detach battery ground lead from battery.
  • For auxiliary batteries: Detach battery minus cables from all auxiliary batteries.
WARNING: Working on fuel system. 
Risk of fire! Danger of explosion! 
  • When working on the fuel system, make sure the workstation has sufficient ventilation, e.g., by means of extraction.
  • Tightly seal off open lines and connections; collect any leakage fuel directly at the point of exit.
  • No fire, sparks, open flames or smoking.
NOTE: RISK OF DAMAGE 
Careless handling of tools and sharp-edged components. 
Scratches, surface damage. 
  • Protect working area.
  • Handle tools and components carefully.
NOTE: TECHNICAL INFORMATION 
Collect and dispose of emerging fluids. Observe country-specific waste disposal regulations.
NOTE: TECHNICAL INFORMATION 
When the engine is stopped after the completion of trip, it may be necessary to run the electric fan. In rare cases, operation of the electric fan can last up to 11 min. This protects the components. In this case, replacing the electric fan will not remedy the problem!

Preliminary work 

Removing the stud bolts on the right cylinder head (cylinder head removed) 

G14252585Courtesy of BMW OF NORTH AMERICA, INC.

Removing the engine venting connector of cylinder bank 1 

G14252586Courtesy of BMW OF NORTH AMERICA, INC.

Removing the spark plugs of cylinder bank 1 (cylinder head removed) 

CAUTION: Swirling dirt particles caused by compressed air. 
Injury hazard! 
  • Collect dirt particles, e.g. when blowing out, use cloth to do so.
  • Wear safety goggles.
NOTE: TECHNICAL INFORMATION 
Clean spark plug slot with compressed air. 
The spark plug shaft must be cleaned using compressed air after having removed the ignition coils and before removing the spark plugs. After having removed the spark plugs, once again check the sealing surface for contamination and (if necessary) clean using a moist cloth or clean using compressed air.
Deposits that are not removed according to instructions may enter the combustion chamber and lead to uncontrolled combustion. Remaining deposits on the spark plug sealing surfaces may lead to leaks and the spark plugs may come loose during engine operation.
Spark plug threads must not be greased or oiled. Insufficiently tightened spark plugs may cause leaks and the sparks plugs may come loose during engine operation.
G10102127Courtesy of BMW OF NORTH AMERICA, INC.
NOTE: TECHNICAL INFORMATION 
Exclusively swiveling extensions may be used for the reversible ratchet. Rigid mounting tool and variable plug connections with rigid option may not be used; there is a risk that the insulator breaks.
G14252588Courtesy of BMW OF NORTH AMERICA, INC.

Removing the engine mounting bracket of cylinder bank 1 

G14252589Courtesy of BMW OF NORTH AMERICA, INC.

Attaching cylinder head of bank 1 to assembly jig, and removing and installing valves 

CAUTION: Heavy component. 
Heavy components can lead to injury or damage. 
  • Remove and install heavy components with the aid of another person/other persons.

Removing the right intake plenum (cylinder head removed) 

G14252590Courtesy of BMW OF NORTH AMERICA, INC.

Removing right Valvetronic servomotor (cylinder head removed) 

G14252591Courtesy of BMW OF NORTH AMERICA, INC.

Installing the cylinder head of cylinder bank 1 on the assembly jig 

CAUTION: Heavy component. 
Heavy components can lead to injury or damage. 
  • Remove and install heavy components with the aid of another person/other persons.
TIGHTENING TORQUE SPECIFICATIONS

Flange to assembly jig
M14X30 Tightening torque  135 Nm
G14252309Courtesy of BMW OF NORTH AMERICA, INC.
G14252598Courtesy of BMW OF NORTH AMERICA, INC.

Removing the exhaust camshaft of cylinder bank 1 

Fig 1: Guide Bearing Screws Loosening Sequence
G14252601Courtesy of BMW OF NORTH AMERICA, INC.

Remove the roller cam follower of the exhaust side of cylinder bank 1 

G14252602Courtesy of BMW OF NORTH AMERICA, INC.

Removing hydraulic valve clearance compensating elements on exhaust side of bank 1 

G14252603Courtesy of BMW OF NORTH AMERICA, INC.

Remove torsion springs 

Precondition 

If the Valvetronic servomotor is installed, the eccentric shaft must be released via the Valvetronic servomotor. 

CAUTION: Spring preload. 
Injury hazard! 
  • The use of the specified special tool (tool) is mandatory.
  • Carry out the described steps properly.
NOTE: The description is provided only at one component. The procedure is the same for all other components.
G14252325Courtesy of BMW OF NORTH AMERICA, INC.

Removing the sliding block of cylinder bank 1 

G14252364Courtesy of BMW OF NORTH AMERICA, INC.

Removing the intake camshaft of cylinder bank 1 

G14252613Courtesy of BMW OF NORTH AMERICA, INC.

Remove the intermediate lever of the intake side 

G14252329Courtesy of BMW OF NORTH AMERICA, INC.

Removing the roller cam follower of the intake camshaft 

NOTE: The description is provided only at one component. The procedure is the same for all other components.
G14252330Courtesy of BMW OF NORTH AMERICA, INC.

Removing the eccentric shaft of cylinder bank 1 

NOTE: RISK OF DAMAGE 
Contaminant or foreign body. 
Contamination can result in malfunctions, loss of function or leaks. 
  • Adhere to the utmost cleanliness.
  • Protect components from contamination e.g. by covering.
  • Close off line connections with seal plugs.
G14252616Courtesy of BMW OF NORTH AMERICA, INC.
G14252617Courtesy of BMW OF NORTH AMERICA, INC.

Setting up cylinder head of bank 1 on special tool 119000 

CAUTION: Heavy component. 
Heavy components can lead to injury or damage. 
  • Remove and install heavy components with the aid of another person/other persons.
G14252339Courtesy of BMW OF NORTH AMERICA, INC.

Remove valves 

G14252341Courtesy of BMW OF NORTH AMERICA, INC.

Replacing the valve stem seals 

NOTE: RISK OF DAMAGE 
Contaminant or foreign body. 
Contamination can result in malfunctions, loss of function or leaks. 
  • Adhere to the utmost cleanliness.
  • Protect components from contamination e.g. by covering.
  • Close off line connections with seal plugs.
NOTE: Schematic diagram is for example purposes. Some parts may differ in certain details.
G14181743Courtesy of BMW OF NORTH AMERICA, INC.

Installing valves 

G14252351Courtesy of BMW OF NORTH AMERICA, INC.

Checking the valves for tightness 

WARNING: Working on fuel system. 
Risk of fire! Danger of explosion! 
  • When working on the fuel system, make sure the workstation has sufficient ventilation, e.g., by means of extraction.
  • Tightly seal off open lines and connections; collect any leakage fuel directly at the point of exit.
  • No fire, sparks, open flames or smoking.
WARNING: Contact with hazardous fluids. 
Hazardous to health! 
  • Note and follow safety instructions on containers.
  • Conduct all work in appropriate personal protective equipment only.
G14252353Courtesy of BMW OF NORTH AMERICA, INC.

Check 

G14252354Courtesy of BMW OF NORTH AMERICA, INC.

Result 

» No fuel escapes from the valves or valve seats.

Measure

Result 

» Fuel escapes from the valves or valve seats.

Measure

Installing the eccentric shaft of cylinder bank 1 

G14252617Courtesy of BMW OF NORTH AMERICA, INC.
NOTE: RISK OF DAMAGE 
Contaminant or foreign body. 
Contamination can result in malfunctions, loss of function or leaks. 
  • Adhere to the utmost cleanliness.
  • Protect components from contamination e.g. by covering.
  • Close off line connections with seal plugs.
G14252616Courtesy of BMW OF NORTH AMERICA, INC.
TIGHTENING TORQUE SPECIFICATIONS

Eccentric shaft bearing brackets
Screw M6 Tightening torque  10 Nm

Releasing tension on special tool 119000 

CAUTION: Heavy component. 
Heavy components can lead to injury or damage. 
  • Remove and install heavy components with the aid of another person/other persons.
G14252334Courtesy of BMW OF NORTH AMERICA, INC.

Installing the roller cam follower of the intake camshaft 

NOTE: The description is provided only at one component. The procedure is the same for all other components.
G14252330Courtesy of BMW OF NORTH AMERICA, INC.

Checking the intermediate lever classification 

NOTE: TECHNICAL INFORMATION 
All intermediate levers are classified. Only one classification may be used per engine.
All intermediate levers must be reinstalled in the same positions in an engine which has already been in use.
G11645292Courtesy of BMW OF NORTH AMERICA, INC.

Installing intermediate lever on intake side 

G14252329Courtesy of BMW OF NORTH AMERICA, INC.

Install intake camshaft of bank 1 

G14252361Courtesy of BMW OF NORTH AMERICA, INC.
NOTE: TECHNICAL INFORMATION 
The rocker arms may slip slightly when the camshaft is positioned. Make sure rocker arms are correctly positioned on the hydraulic valve clearance compensating elements and on valves.
TIGHTENING TORQUE SPECIFICATIONS

Intake/exhaust camshaft
M6 Snug torque  10 Nm
Tightening torque  10.5 Nm
TIGHTENING TORQUE SPECIFICATIONS

Intake/exhaust camshaft
M6 Snug torque  10 Nm
Tightening torque  10.5 Nm
G14252363Courtesy of BMW OF NORTH AMERICA, INC.

Install sliding blocks of bank 1 

TIGHTENING TORQUE SPECIFICATIONS

Sliding block on cylinder head
Screw M7x35 10.9 Tightening torque  23 Nm
G14252364Courtesy of BMW OF NORTH AMERICA, INC.
G14252365Courtesy of BMW OF NORTH AMERICA, INC.

Installing torsion springs 

CAUTION: Spring preload. 
Injury hazard! 
  • The use of the specified special tool (tool) is mandatory.
  • Carry out the described steps properly.
NOTE: The description is provided only at one component. The procedure is the same for all other components.
TIGHTENING TORQUE SPECIFICATIONS

Torsion spring on cylinder head
M6x20 screw tightening torque  8.8 Nm
G14252323Courtesy of BMW OF NORTH AMERICA, INC.
G14252325Courtesy of BMW OF NORTH AMERICA, INC.

Installing hydraulic valve clearance compensating elements on exhaust side of cylinder bank 1 

G14252603Courtesy of BMW OF NORTH AMERICA, INC.

Installing roller cam follower of the exhaust side of bank 1 

G14252602Courtesy of BMW OF NORTH AMERICA, INC.

Install exhaust camshaft of the bank 1 

G14252600Courtesy of BMW OF NORTH AMERICA, INC.
NOTE: To provide a better overview: Schematic diagram with partially hidden components.
TIGHTENING TORQUE SPECIFICATIONS

Intake/exhaust camshaft
M6 Snug torque  10 Nm
Tightening torque  10.5 Nm
Fig 2: Guide Bearing Screws Tightening Sequence
G14252601Courtesy of BMW OF NORTH AMERICA, INC.
TIGHTENING TORQUE SPECIFICATIONS

Intake/exhaust camshaft
M6 Snug torque  10 Nm
Tightening torque  10.5 Nm
G11645110Courtesy of BMW OF NORTH AMERICA, INC.

Remove the cylinder head of cylinder bank 1 from the assembly jig 

CAUTION: Heavy component. 
Heavy components can lead to injury or damage. 
  • Remove and install heavy components with the aid of another person/other persons.
G14252598Courtesy of BMW OF NORTH AMERICA, INC.

Install Valvetronic servomotor, right (cylinder head removed) 

NOTE: TECHNICAL INFORMATION 
The work must be performed with vehicle care to prevent component damage.
CONSUMABLE SPECIFICATIONS

Lubricating grease Longtime PD-1  400 g, Cartridge 83192160340
G14252380Courtesy of BMW OF NORTH AMERICA, INC.
TIGHTENING TORQUE SPECIFICATIONS

Valvetronic servomotor on cylinder head
M6x16-8.8 Tightening torque  9.6 Nm
G14252591Courtesy of BMW OF NORTH AMERICA, INC.

Installing right intake plenum (cylinder head removed) 

G14252382Courtesy of BMW OF NORTH AMERICA, INC.
TIGHTENING TORQUE SPECIFICATIONS

Pressure sensor
screw Tightening torque  3 Nm
TIGHTENING TORQUE SPECIFICATIONS

Intake plenum
M6 screw Tightening torque  10 Nm
G14252590Courtesy of BMW OF NORTH AMERICA, INC.
TIGHTENING TORQUE SPECIFICATIONS

Intake plenum
M8 screw Tightening torque  21.4 Nm

Install engine mounting bracket of bank 1 

TIGHTENING TORQUE SPECIFICATIONS

Engine suspension element
M8x22 screw Tightening torque  20 Nm
G14252589Courtesy of BMW OF NORTH AMERICA, INC.

Installing the spark plugs of bank 1 (cylinder head removed) 

NOTE: The description is provided only at one component. The procedure is the same for all other components.
NOTE: TECHNICAL INFORMATION 
Do not drop spark plug into spark plug shaft! This can lead to a reduction of the electrode gap and can thus impair smooth running of the engine, especially in idle position.
G10102129Courtesy of BMW OF NORTH AMERICA, INC.
NOTE: TECHNICAL INFORMATION 
Exclusively swiveling extensions may be used for the reversible ratchet. Rigid mounting tool and variable plug connections with rigid option may not be used; there is a risk that the insulator breaks.
G14252588Courtesy of BMW OF NORTH AMERICA, INC.
TIGHTENING TORQUE SPECIFICATIONS

Spark plugs
M12x1.25 Tightening torque  23 Nm

Installing venting connector of bank 1 

TIGHTENING TORQUE SPECIFICATIONS

Venting connector/special tool to cylinder head
M8x1
Replace the venting connector.
Tightening torque  15 Nm
G14252586Courtesy of BMW OF NORTH AMERICA, INC.

Installing stud bolts on the right cylinder head 

Precondition 

Cylinder head is removed.

TIGHTENING TORQUE SPECIFICATIONS

Stud bolt on cylinder head
M8x50
Replace the stud bolt.
tightening torque  20 Nm
G14252585Courtesy of BMW OF NORTH AMERICA, INC.
TIGHTENING TORQUE SPECIFICATIONS

Exhaust manifold to cylinder head
M8
Replace nuts.
tightening torque  15 Nm
G14252583Courtesy of BMW OF NORTH AMERICA, INC.

Follow-up work