Fuel Delivery and Air Induction: Testing and Inspection

11 61 730 - BMW leak test for intake system (N54)





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.
Mixing up the functions will result in damage to the engine.





Necessary preliminary tasks:
- Release upper section of intake air filter.
- Prepare BMW diagnosis system.
- Start diagnosis program.
1. - Drive
2. - Engine electronics
3 - Air supply
4. - Boost pressure control
or - Perception



Lack of power
Note on ordering:
- Workshop planning.
- Measuring and test equipment.
- No. 81 29 0 426 464





Pressure measurement:
Prepare BMW diagnosis system on diagnosis unit.
1. - Screw in pressure sensor.
2. - Overpressure connection (Blue).
3. - Connect stimuli cables (3) to positive and negative.
4. - Connect 12V battery cables (4) to vehicle battery positive and negative.





Secure seal plug (1) with union nut (2) in intake duct and seal.

Note:
Twin-Turbo: both intake ducts must be sealed.





Insert Blue pneumatic hose (4) in pneumatic coupling (2) of sealing plug (1).
Seal plug (3) has no pneumatic coupling.





Vacuum pressure measurement:
Prepare diagnosis tester on diagnosis unit.
1. - Screw in pressure sensor.
2. - Connect stimuli cables (2) to positive and negative.
3. - Connect 12V battery cables (3) to vehicle battery positive and negative.
4. - Controller for vacuum connection.
5. - Vacuum connection (Red).





Calibration for vacuum pressure measurement:
Seal stop cock (2) in direction of arrow.
Release lock nut on controller (1).
Carry out pressure adjustment in accordance with BMW diagnosis instruction.
Secure controller (1) hand-tight against turning.
Open stop cock (2) again.





Connections on EPPC:
1 - Connection (VAC) to vacuum reservoir.
2 - Connection (OUT) with ring to turbocharger.





Checking wastegate on cylinders 1-3:
Detach vacuum line from EPPC (2), cylinders 1-3 (OUT).
Disconnect connecting line with suitable tool (1).
Attach vacuum line to pneumatic coupling (3) with Red pneumatic hose in direction of arrow.





Checking wastegate on cylinders 4-6:
Detach vacuum line from EPPC (2), cylinders 4-6 (OUT).
Disconnect connecting line with suitable tool (1).
Attach vacuum line to pneumatic coupling (3) with Red pneumatic hose in direction of arrow.





Initial position (1) of wastegate linkage depressurized.
Wastegate valve opened.





Initial position (1) of wastegate linkage with vacuum pressure.
Wastegate valve closed.





Checking wastegate valve (1) with vacuum pressure:
Wastegate valve must be opened without vacuum pressure.
The wastegate valves must close if a vacuum pressure is applied at the wastegate sockets (see BMW diagnosis system).
Check shaft on turbine wheel for rotatability.





Checking pop-off valves:

Necessary preliminary tasks:
- Remove both pop-off valves

Note:
To check the function of the pop-off valves (2), it is necessary to build up vacuum pressure at the valves.
Establish vacuum pressure with the BMW auxiliary diagnosis unit - vacuum.

Connect vacuum hose (3).

Establish vacuum pressure at 500 mbar.
Plunger (1) must visibly release the opening in the direction of the arrow as far as it will go.

Important!
Plunger (1) must maintain this position while vacuum pressure is being created.
If this is not the case, replace the pop-off valve (2).

Assemble engine.





Observe BMW diagnosis instructions.