11 65 580 Replacing vacuum unit (wastegate valve) (N54, N54T)

IMPORTANT: Overpressure and vacuum lines are identified by the size of the seals and color-coded Red and Blue and must not be mixed up with each other.
Build up pressure with Blue color.
Generate vacuum pressure with Red color.
Check ease of movement between turnbuckle and pin of adjusting lever (ensure rectangularity).

Note on ordering:

Workshop equipment
Workshop planning
Workshop equipment catalogue
Measuring and test equipment
No. 81 29 0 426 464

Necessary preliminary tasks

Prepare BMW diagnosis system
Start diagnosis program
Noticeable symptoms:
1. Noises at exhaust turbocharger (clankin or Fault entry):
  1. Power train
  2. Engine electronics
  3. Air supply
  4. Charging pressure co
Remove both exhaust turbochargers . See 11 65 022 REMOVING AND INSTALLING/REPLACE EXHAUST TURBOCHARGER FOR CYLINDERS 1-3 (N54, N54T) or 11 65 024 REMOVING AND INSTALLING/REPLACE EXHAUST TURBOCHARGER FOR CYLINDERS 4-6 (N54, N54T) .

Release retaining clip (2).

Disengage linkage of vacuum unit (wastegate valve).

Fig 1: Identifying Retaining Clip

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Check linkage and valve for wear

Connect vacuum line (1) to vacuum unit (wastegate valve).

Vacuum linkage must retract to stop.

Wastegate valve must be sealed off by hand.

Fig 2: Connecting Vacuum Line To Vacuum Unit (Wastegate Valve)

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Release lock nut on controller (1).

Press setting with measurement.

Determine ambient pressure
Seal stop cock (2) in direction of arrow
Set controller (1) to 500 ± 10 mbar below ambient pressure (e.g. 980 - 500 = 480 mbar)

Fig 3: Removing Lock Nut On Controller
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Open stop cock (2) again.

Wastegate linkage closes.

Determine gap dimension.

Gap dimension between turnbuckle and adjusting lever.

Fig 4: Identifying Gap Dimension Between Turnbuckle And Adjusting Lever

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Seal off wastegate valve (1) by hand in direction of arrow up to stop.

The turbocharger must be replaced if a 1.5 mm drill bit can be inserted as pictured.

NOTE: Gap dimension ≥ 1.5 mm.

Fig 5: Sealing Off Wastegate Valve By Hand

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The turbocharger is OK if a 1.5 mm drill bit cannot be inserted or can only be inserted at an angle as pictured.

NOTE: Gap dimension ≥ 1.5 mm.

Fig 6: Inserting Drill Bit In Turbocharger

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Release screws (1 and 3).

Tightening torque: 11 65 11AZ .

Installation note:

Replace vacuum unit 2 (wastegate valve).

Fig 7: Identifying Vacuum Unit 2 (Wastegate Valve) Screws

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Adjusting vacuum unit (wastegate valve) linkage

Initial position of vacuum unit (wastegate valve) linkage depressurized.

Connect red vacuum line (1) to vacuum unit (wastegate valve).

Fig 8: Identifying Red Vacuum Line To Vacuum Unit (Wastegate Valve)

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Vacuum pressure measurement

Prepare BMW diagnosis system on vacuum diagnosis unit.

Screw in pressure sensor.
Connect 12V battery cables (2) to vehicle battery positive and negative.
Connect 12V battery cables (3) to vehicle battery positive and negative (pump operation max. 3 mins.) .
Controller for vacuum connection.
Vacuum connection (Red).

Fig 9: Connecting Stimuli Cables To Positive And Negative
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Calibration for vacuum pressure measurement

Release lock nut on controller (1).

Press setting with measurement.

Determine ambient pressure
Seal stop cock (2) in direction of arrow
Set controller (1) to 200 ± 10 mbar below ambient pressure (e.g. 980 - 200 = 780 mbar).

Fig 10: Removing Lock Nut On Controller
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Open stop cock (2) again.

Wastegate valve closes.

Initial position (1) of wastegate linkage with preset vacuum pressure.

Wastegate valve virtually closed.

Fig 11: Identifying Initial Position Of Wastegate Linkage With Preset Vacuum Pressure

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Checking turnability at wastegate valve

Wastegate valve can be turned with minimal force.
Adjustment at wastegate valve is OK.
Wastegate valve has play and can be turned without resistance, wastegate valve open too far.
Carry out adjustment at wastegate valve, shorten linkage.
Wastegate valve cannot be turned, wastegate valve closed.

Fig 12: Checking Turnability At Wastegate Valve
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Carry out adjustment at wastegate valve, lengthen linkage.

Adjustment at linkage

To lengthen linkage, turn turnbuckle (1) max. 180° in counterclockwise direction.

To shorten linkage, turn turnbuckle (1) max. 180° in clockwise direction.

Engage turnbuckle (1) on adjusting lever in direction of arrow.

IMPORTANT: Check ease of movement between turnbuckle (1) and pin of adjusting lever (ensure rectangularity).

Check turnability at wastegate valve again.

Fig 13: Engaging Turnbuckle On Adjusting Lever

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Secure lock nut (1); to do so, secure turnbuckle against turning with a suitable tool.

Tightening torque: 11 65 10AZ .

Mount locking clip (2).

Fig 14: Identifying Lock Nut And Locking Clip

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Assemble engine.

Observe diagnosis instructions.

Execute test module for boost pressure control.