11 61 730 BMW leakage test for air intake system (N20/N26)

Special tools required:

IMPORTANT: Excess pressure 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.
Mixing up the functions will result in damage to the engine.

Necessary preliminary tasks:

Prepare BMW diagnosis system.
Start diagnosis program.
1. Power train
2. Engine electronics
3. Air supply
4. Charging pressure control
  or Perception
  
  or Lack of power

Diagnosis instruction Check air intake system for leaks .

Pressure measurement:

Prepare BMW diagnosis system on diagnosis unit.

Fit connector (81 29 2 158 850) on diagnosis auxiliary device (81 29 0 426 464).
Connect pressure hose 2 201 924 on diagnosis auxiliary device (81 29 0 426 464).
Overpressure connection (Blue).
Connect 12 V cable (3), positive battery terminal and negative terminal.
Connect 12 V cable (4), positive battery terminal and negative terminal.

Fig 1: Checking Overpressure Connection
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Insert the blue overpressure lines on the diagnosis auxiliary device 0 426 464 on the connector (1).

Connect IMIB (3) with connector (2) of the auxiliary diagnosis device using pressure hose 2 201 924.

Graphic N63.

Fig 2: Inserting Blue Overpressure Lines On Diagnosis Auxiliary Device (0 426 464)

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Disconnect clean air pipe at intake silencer housing.

Screw seal plug 2 285 501 (B11) air-tight onto clean air pipe.

Connect the auxiliary diagnosis device with the seal plug by means of the blue pressure line.

Fig 3: Disconnecting Air Pipe Of Intake Silencer Housing

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Diagnosis instruction Check turbocharging path with charge air cooler for leaks .

Unlock snap fastener (1) on exhaust turbocharger.

Disconnect pressure hose at exhaust turbocharger.

NOTE: Shown with engine/cooling package removed for better overview.

Fig 4: Identifying Charge Air Guide Snap Fastener

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Close off pressure hose air-tight to the charge air cooler with the seal plug 2 285 501 (A11).

Fig 5: Removing Charge Air Cooler

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Unlock retaining clip (1) on the throttle valve pressure hose.

Unclip tank ventilation line (2) from bracket.

Unlock and disconnect plug connection (4) on charging pressure sensor.

Undo connecting coupling (5) of the tank ventilation line.

Fig 6: Removing Retaining Clip On Throttle Valve Pressure Hose

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Required seal plug.

Part Number 13 90 7 515 387

Fig 7: Identifying Special Tool (7 515 387)

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Unlock tank ventilation line at the pressure pipe and close off with seal plug 7 515 387.

Fig 8: Removing Tank Ventilation Line

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Prepare pressure gauge from the tool set 2 285 501 with pressure hose.

Close off pressure pipe with seal plug 2 285 501 (C11).

Set pressure gauge to 1 bar with adjusting screw.

Close off sliding piece (1) on pressure gauge in direction of arrow.

Fig 9: Closing Pressure Pipe Using Seal Plug

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Diagnosis instruction Leak detection with BMW smoke tester .

Disconnect the overpressure line (2) on the diagnosis auxiliary device.

Connect pressure line (1) from the BMW smoke tester 2 353 954 with the overpressure line (2).

Fig 10: Checking Pressure Line Using BMW Smoke Tester

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Put the BMW smoke tester 2 353 954 into operation according to the operating instructions.

Fig 11: Identifying BMW Smoke Tester (2 353 954)

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Follow diagnosis instruction.