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Home >> BMW >> 2025 >> 230i >> Repair and Diagnosis >> External Pages >> Different car >> Section 246 (Cylinder Head -- Repair M4 (G82 & G83)) >> 11 12 Cylinder Head With Lid >> 11 12 161 Replace cylinder head (M4 AWD models, 2021-2023) >> Replacing the cylinder head (remounting components)

Replacing the cylinder head (remounting components)

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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: Hot surfaces  .
Risk of burning! 
  • Perform all work only on components that have cooled down.
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.
CAUTION: On releasing high pressure line, fuel may emerge at high speed  .
Injury hazard! 
  • Wear suitable personal protective equipment.
  • Before performing any installation work, allow cooling system to cool down to less than 40°C.
  • Note warnings on cylinder head cover.
NOTE: RISK OF DAMAGE 
Engine damage due to missing motor oil  .
Missing motor oil following replacement of the cylinder head or the engine can lead to damage on the valve train  .
NOTE: TECHNICAL INFORMATION 
Collect and dispose of emerging fluids. Observe country-specific waste disposal regulations.

Preliminary work 

CAUTION: Heavy component  .
Heavy components can lead to injury or damage  .
  • Remove and install heavy components with the aid of another person/other persons.
NOTE: RISK OF DAMAGE 
Damage of the electric wastegate valve controller  .
Excessive force when removing and installing a jammed exhaust turbocharger may damage the electric wastegate valve controller  .
  • Do not pull on the electrical wastegate valve controller or on the coupling rod.
  • Apply force only at the turbine housing and exhaust manifold.
  • Do not pull on the compressor housing.
G15329687Courtesy of BMW OF NORTH AMERICA, INC.
NOTE: TECHNICAL INFORMATION 
Exhaust manifold/exhaust turbocharger is not bolted to the underside, but clamped instead. When removing/replacing the exhaust manifold/exhaust turbocharger, the trim strip remains screwed on.
G15329690Courtesy of BMW OF NORTH AMERICA, INC.
NOTE: TECHNICAL INFORMATION 
Exhaust manifold/exhaust turbocharger is not bolted to the underside, but clamped instead. When removing/replacing the exhaust manifold/exhaust turbocharger, the trim strip remains screwed on.
G15329698Courtesy of BMW OF NORTH AMERICA, INC.
NOTE: TECHNICAL INFORMATION 
When assembling, it is essential to observe screwing sequences and tightening torques.
Failure to comply with the regulations can lead to leaks and damage.
TIGHTENING TORQUE SPECIFICATIONS

Trim strip for exhaust turbocharger on cylinder head
M7X27 10.9
Observe tightening sequence!
Replace screws.
1. Joining torque 
2. Angle of rotation 
20 Nm
90°
G15329700Courtesy of BMW OF NORTH AMERICA, INC.
NOTE: TECHNICAL INFORMATION 
When assembling, it is essential to observe screwing sequences and tightening torques.
Failure to comply with the regulations can lead to leaks and damage.
TIGHTENING TORQUE SPECIFICATIONS

Trim strip for exhaust turbocharger on cylinder head
M7X27 10.9
Observe tightening sequence!
Replace screws.
1. Joining torque 
2. Angle of rotation 
20 Nm
90°
TIGHTENING TORQUE SPECIFICATIONS

Heat shield to cylinder head
M8X17.5
Replace screws.
tightening torque  10 Nm
G15329702Courtesy of BMW OF NORTH AMERICA, INC.

Check 

CAUTION: Heavy component  .
Heavy components can lead to injury or damage  .
  • Remove and install heavy components with the aid of another person/other persons.
G15329703Courtesy of BMW OF NORTH AMERICA, INC.
NOTE: RISK OF DAMAGE 
Damage of the electric wastegate valve controller  .
Excessive force when removing and installing a jammed exhaust turbocharger may damage the electric wastegate valve controller  .
  • Do not pull on the electrical wastegate valve controller or on the coupling rod.
  • Apply force only at the turbine housing and exhaust manifold.
  • Do not pull on the compressor housing.
NOTE: TECHNICAL INFORMATION 
When replacing the stud bolts, they must be coated with screw locking agent (Loctite 270).
TIGHTENING TORQUE SPECIFICATIONS

Stud bolt on cylinder head
M7X58 tightening torque  12 Nm
SEALING COMPOUND DESCRIPTION

Loctite 270  10 ml, Bottle 83192210337

Result 

» Loose stud bolt (1)  .

Measure

G15329704Courtesy of BMW OF NORTH AMERICA, INC.
NOTE: RISK OF DAMAGE 
Damage to the surface  .
The use of metal-cutting tools (e.g., emery cloths) for cleaning surfaces can damage them and lead to leaks and/or engine damage  .
  • Do not use any metal-cutting tools.
G15329705Courtesy of BMW OF NORTH AMERICA, INC.
NOTE: RISK OF DAMAGE 
Damage to the surface  .
The use of metal-cutting tools (e.g., emery cloths) for cleaning surfaces can damage them and lead to leaks and/or engine damage  .
  • Do not use any metal-cutting tools.
G15329708Courtesy of BMW OF NORTH AMERICA, INC.
NOTE: TECHNICAL INFORMATION 
Note the installation position of the component. The component can be installed in various installation positions.
G15329709Courtesy of BMW OF NORTH AMERICA, INC.
NOTE: TECHNICAL INFORMATION 
When assembling, it is essential to observe screwing sequences and tightening torques.
Failure to comply with the regulations can lead to leaks and damage.
Fig 7: Exhaust Turbocharger Nuts Tightening Sequence
G15329710Courtesy of BMW OF NORTH AMERICA, INC.
TIGHTENING TORQUE SPECIFICATIONS

Exhaust turbocharger to cylinder head
M7
Observe tightening sequence!
Replace nuts.
1. Joining torque  10 Nm
2. tightening torque  10 Nm
3. Joining torque  16 Nm
4. tightening torque  16 Nm
5. Tightening torque  16 Nm
G15329711Courtesy of BMW OF NORTH AMERICA, INC.
NOTE: Note the installation position of the component. The component can be installed in various installation positions.
G15329712Courtesy of BMW OF NORTH AMERICA, INC.
NOTE: TECHNICAL INFORMATION 
When assembling, it is essential to observe screwing sequences and tightening torques.
Failure to comply with the regulations can lead to leaks and damage.
Fig 8: Exhaust Turbocharger Nuts Tightening Sequence
G15329713Courtesy of BMW OF NORTH AMERICA, INC.
TIGHTENING TORQUE SPECIFICATIONS

Exhaust turbocharger to cylinder head
M7
Observe tightening sequence!
Replace nuts.
1. Joining torque  10 Nm
2. tightening torque  10 Nm
3. Joining torque  16 Nm
4. tightening torque  16 Nm
5. Tightening torque  16 Nm
TIGHTENING TORQUE SPECIFICATIONS

Heat shield to cylinder head
M8X17.5
Replace screws.
tightening torque  10 Nm
G15329714Courtesy of BMW OF NORTH AMERICA, INC.

Follow-up work