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Home >> Porsche >> 2016 >> Macan Turbo >> Repair and Diagnosis >> External Pages >> Different car >> Section 295 (10 - Engine - Crankcase, Suspension -- 911 CARRERA (991)) >> WM 101802 Checking Pressure Loss Of Cylinders (Except CARRERA "Edition", CARRERA Cabriolet "Edition", CARRERA 4 "Edition", CARRERA 4 Cabriolet "Edition", Gt3 RS) >> Checking Pressure Loss Of Cylinders >> The Scope Of Work Described Here Was Carried Out Using The Recommended Tester

The Scope Of Work Described Here Was Carried Out Using The Recommended Tester

WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2019 Porsche 911, 2018 Porsche 911, 2017 Porsche 911, 2016 Porsche 911, and 2015 Porsche 911. However, it is still accessible from the selected car via links, so may be relevant.
WARNING: Engine can turn without control (the crankshaft can turn because of the pressure in the cylinder).
  • Danger of crushing (injury)
  • Tools can become jammed (material damage)

→ The piston must be exactly at top dead center (TDC) position (secure the crankshaft).

→ Do not touch any belt drive components when building up pressure.

→ Do not insert any tools on the crankshaft belt pulley.

  1. Set the piston position (ignition TDC) and connect test tools.
    1. 1.1. Screw in adapter -1-  for M14 spark plug thread and tighten hand-tight. Connect dead-center position gauge -2-  .
      Fig 1: Checking Piston Position Using Dead-Centre Position Gauge
      G09990446Courtesy of PORSCHE CARS NORTH AMERICA, INC.
    2. 1.2. Turn the crankshaft clockwise at the vibration damper as far as the TDC marking of cylinder 1 using turning device 9773  .
    3. 1.3. Determine the piston position (ignition TDC) of the cylinder to be checked using the dead-center position gauge.
      1. 1.3.1. Piston position of the cylinder to be checked is correct:

        Continue with Step  1.4 (Fix vibration damper in place).

      2. 1.3.2. Piston position of the cylinder to be checked is incorrect (overlap):

        Continue to turn the crankshaft 360° clockwise at the vibration damper.

    4. 1.4. Fix vibration damper -1-  in place with locating pin 9595/1 -4-  .
      Fig 2: Disconnecting Vibration Damper
      G09990447Courtesy of PORSCHE CARS NORTH AMERICA, INC.
    5. 1.5. Remove the dead-centre position gauge.
  2. Set the pressure gauge -1-  .
    1. 2.1. Connect the compressed air hose -2-  to the pressure gauge.
    2. 2.2. Connect the compressed air hose to the compressed air system.
    3. 2.3. Pull and turn the pressure-regulating valve -3-  until the pointer on the pressure loss tester shows 23 % -arrow-  .
    4. 2.4. Lock the pressure-regulating valve. Disconnect compressed air hose.
      Fig 3: Installing Pressure Gauge
      G09990448Courtesy of PORSCHE CARS NORTH AMERICA, INC.

    Information 

    • Pressure of between 6 and 12 bar is required for carrying out the pressure loss test. 
    • Start the test at cylinder 1 and continue according to firing order (1 - 6 - 2 - 4 - 3 - 5). 
  3. Connect the pressure gauge -1-  to the adapter -3-  .
    1. 3.1. Secure the pressure gauge with tie-wraps -2-  and connect the test hose to the adapter -arrow-  .
    2. 3.2. Connect the compressed air hose to the pressure gauge.
      Fig 4: Connecting Pressure Gauge To Adapter
      G09990449Courtesy of PORSCHE CARS NORTH AMERICA, INC.
  4. Check the pressure loss.
    1. 4.1. The pointer on the pressure gauge must move within the green area (0-25 %). 

      A loss in pressure of more than 25 % is no longer acceptable and the source of the problem must be found! 

    2. 4.2. Pressure loss within tolerance range:
      1. 4.2.1. Check the pressure loss on the next cylinder in the same way as for cylinder 1.

        Firing order: 1 - 6 - 2 - 4 - 3 - 5 

    3. 4.3. Pressure loss not within tolerance range:
      1. 4.3.1. Locate the leak by listening for sounds of escaping air.

        The following areas can be checked: 

        Intake manifolds (checking intake valves)

        Exhaust manifolds and exhaust pipes (checking outlet valves)

        Positive crankcase ventilation and oil filler neck (checking piston rings)

        Coolant filler neck and spark plug bore of adjacent cylinder (checking cylinder head gasket)

      2. 4.3.2. Then, continue checking the next cylinder in the same way as for cylinder 1.

        Firing order: 1 - 6 - 2 - 4 - 3 - 5 

  5. Remove the turning device from the vibration damper.