Wastegate: Service and Repair
11 65 580 Replacing vacuum unit (wastegate valve) (N54, N54T)
Important!
Overpressure and vacuum lines are identified by the size of the seals and colour-coded Red and Blue and must not be mixed up with each other.
Build up pressure with Blue colour.
Generate vacuum pressure with Red colour.
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
Wahrnehmung:
1. Noises at exhaust turbocharger (clanking)
Order Fault entry:
1. Drive
2. Engine electronics
3. Air supply
4. Charging pressure control
^ Remove both exhaust turbochargers
Release locking clip (2).
Disengage linkage of vacuum unit (wastegate valve).
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.
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)
Open stop cock (2) again.
Wastegate linkage closes.
Determine gap dimension.
Gap dimension between turnbuckle and adjusting lever.
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.
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.
Unfasten screws (1 and 3).
Tightening torque 11 65 11AZ.
Installation note:
Replace vacuum unit 2 (wastegate valve).
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).
Vacuum pressure measurement:
Prepare BMW diagnosis system on vacuum diagnosis unit.
1. Screw in pressure sensor.
2. Connect 12V battery cables (2) to vehicle battery positive and negative.
3. Connect 12V battery cables (3) to vehicle battery positive and negative (pump operation max. 3 minds.).
4. Controller for vacuum connection.
5. Vacuum connection (Red).
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).
Open stop cock (2) again.
Wastegate valve closes.
Initial position (1) of wastegate linkage with preset vacuum pressure.
Wastegate valve virtually closed.
Checking turnability at wastegate valve.
a. Wastegate valve can be turned with minimal force.
Adjustment at wastegate valve is OK.
b. Wastegate valve has play and can be turned without resistance, wastegate valve open too far.
Carry out adjustment at wastegate valve, shorten linkage.
c. Wastegate valve cannot be turned, wastegate valve closed.
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.
Secure lock nut (1); to do so, secure turnbuckle against turning with a suitable tool.
Tightening torque 11 65 10AZ.
Mount locking clip (2).
Assemble engine.
Observe diagnosis instructions.
Execute test module for boost pressure control.
