ECD SYSTEM Turbocharger Noise

DESCRIPTION

Tech Tips

Turbocharger noise is classified into two types. These are whistling sound and chattering sound. During troubleshooting, first determine the type of noise.

Description
Noise Type Noise Description Main Trouble Area
Whistling sound (airflow sound) The whistling sound volume and pitch are proportional to the turbocharger or engine speed. The abnormal noise level becomes clear when the engine speed is increased.

  • Turbocharger (example: unstable shaft)

  • Transmission gears

  • Leak in intake system

  • Damaged intake system
Chattering sound (metallic sound) The chattering sound pitch is lower than the whistling sound pitch. Has a comparatively constant pitch that is independent of the engine speed and vehicle speed.

Turbocharger

Tech Tips


  • The turbocharger vibrations are transmitted to the exhaust pipe, causing noise and resonance.

  • The turbocharger vibrations are transmitted through the exhaust pipe to the chassis (floor), causing noise and resonance in the chassis.

  1. Faults and Symptoms of Diesel Engine Components

    Turbocharger System
    Main fault

    Unstable turbocharger turbine shaft

    (interference, seizing, poor balance, etc.)
    Symptoms

    • High-pitched whistling noise

      Tech Tips

      The volume and pitch are proportional to the turbocharger speed.

    • Metallic sound due to looseness
    Intake System
    Main fault Leak
    Symptoms Abnormal noise during intake leak
    Transmission Gear
    Symptoms

    Gear noise

    Tech Tips

    The pitch and volume change in proportion to the transmission gear speed.

PROCEDURE


  1. CONFIRM CONDITION IN WHICH NOISE OCCURRED


    1. Confirm with the customer the condition when noise occurred.

      Tech Tips

      To clearly understand the conditions in which the noise occurred, the items in the table below are useful.

      Item Note
      Engine speed Engine speed range
      Vehicle speed Vehicle speed range
      Transmission gear Which gear?
      Accelerator pedal position During acceleration or deceleration?
      Temperature

      • Ambient temperature

      • Engine temperature (cold, warmed up, etc.)
      Road conditions

      • City or highway driving

      • Uphill or downhill
      Noise level

      • Did the noise occur suddenly, or build gradually?

      • Has the noise gradually been getting louder?
      Other symptoms

      • Lack of power

      • High fuel consumption, etc.
      Noise recognition What made the customer determine that the sound was a malfunction?

    NEXT

  2. PERFORM SIMULATION TEST


    1. Check whether the noise described by the customer occurs.

      Tech Tips

      If an abnormal noise is heard, check whether it matches the noise described by the customer.

      Result:
      Result Proceed to
      Abnormal noise generated while idling (ticking or rattling (metallic sound)) A
      Abnormal noise generated while driving B

    B

    CONFIRM NOISE SOURCE (FROM TURBOCHARGER OR NOT) Click here

    A

  3. CHECK FOR NOISE FROM SOURCE OTHER THAN TURBOCHARGER


    1. Check for the noise source with a sound scope.

    2. The source of the noise is not the turbocharger, but a part other than the turbocharger (e.g. a part inside the engine, transmission, or vacuum pump).

    3. Sometimes gear noise may be mistaken for turbocharger noise. For gear noise, pay attention to the gear inside the engine and transmission gear.

    4. Rev the engine up and check if the noise reduces at the same time the engine speed decreases. If the noise reduces at the same time the engine speed decreases, it is gear noise. If the noise reduces a short time after the engine speed decreases, it is turbocharger noise.

    5. Check whether the noise described by the customer occurs.

      Result:
      Result Proceed to
      Abnormal noise generated from turbocharger A
      Abnormal noise generated from parts other than turbocharger B

    B

    CHECK FOR NOISE FROM SOURCE OTHER THAN TURBOCHARGER (PROCEDURE 8) Click here

    A

  4. CHECK TURBOCHARGER SUB-ASSEMBLY


    1. Check for damage to the compressor impeller.

    2. Check for interference between the compressor impeller and the compressor housing.

      Result:
      Result Proceed to
      No damage or interference A
      Damage or interference exists B

    A

    END (CAUSE CHECK EXCEPT THE TURBO CHARGER)

    B

    REPLACE TURBOCHARGER SUB-ASSEMBLY Click here

  5. CONFIRM NOISE SOURCE (FROM TURBOCHARGER OR NOT)


    1. Connect the GTS to the DLC3.

    2. Start the engine and warm it up.

    3. Turn the GTS on.

    4. Enter the following menus: Powertrain / Engine and ECT / Active Test / Activate the VN Turbo Open.

    5. Perform the Active Test under the conditions* from the time the noise occurred described by the customer and compare the noise to the noise heard when not performing the Active Test and check if the noise is reduced.

      Tech Tips

      *: Some examples of conditions are idling, racing the engine and driving at full throttle.

      Result:
      Result Proceed to
      The noise is reduced (or disappears) A
      The noise is the same as in Procedure 2 (The noise does not change) B

      Tech Tips


      • By performing Activate the VN Turbo Open Active Test, the variable nozzle of the turbocharger sub-assembly becomes fully open regardless of the engine condition, and the turbocharger speed does not increase.

      • If the turbocharger sub-assembly is the cause of the noise, the noise will be reduced when Activate the VN Turbo Open Active Test is performed because turbocharger speed does not increase.


    B

    CHECK FOR NOISE FROM SOURCE OTHER THAN TURBOCHARGER (PROCEDURE 8) Click here

    A

  6. PERFORM SIMULATION TEST


    1. Check whether the noise described by the customer occurs.

      Tech Tips

      If an abnormal noise is heard, check whether it matches the noise described by the customer.

    2. If an abnormal noise is confirmed, determine which system emits it.

      Result:
      Result Proceed to
      Noise occurs (squealing (metallic sound) when driving) A
      Noise occurs (hissing (airflow sound) when driving) B
      Noise occurs (whistling or foghorn-like (airflow sound) during acceleration) C
      Noise occurs (whistling (airflow sound) during deceleration) D

    A

    CHECK TURBOCHARGER SUB-ASSEMBLY Click here

    B

    CHECK TURBOCHARGER SUB-ASSEMBLY Click here

    C

    CHECK TURBOCHARGER SUB-ASSEMBLY Click here

    D

  7. CHECK GEAR NOISE


    1. Check if gear noise is the source of the abnormal noise (not noise from the turbocharger).


    NEXT

    ELIMINATE THE CAUSE OF THE NOISE

  8. CHECK FOR NOISE FROM SOURCE OTHER THAN TURBOCHARGER (PROCEDURE 8)


    1. Check for the noise source.

      CAUTION:

      When performing this check, make sure that the sound scope, your body, etc., do not get caught on the V-belt.

      Tech Tips


      • The source of the noise is not the turbocharger sub-assembly, but a part other than the turbocharger sub-assembly (e.g. a part inside the engine, transmission, or vacuum pump).

      • Sometimes gear noise may be mistaken for turbocharger noise. For gear noise, pay attention to the gear inside the engine and transmission gear.

      • Rev the engine up and check if the noise reduces at the same time the engine speed decreases. If the noise reduces at the same time the engine speed decreases, it is gear noise. If the noise reduces a short time after the engine speed decreases, it is turbocharger noise.


    NEXT

  9. REPLACE THE PARTS DETECTED IN PROCEDURE 8


    1. Replace the parts detected in Procedure 8 as the noise source.


    NEXT

  10. CONFIRM CONFIRM WHETHER THE NOISE PROBLEM HAS BEEN SUCCESSFULLYSOLVED


    1. Check whether the noise problem has been successfully solved.


    NEXT

    END

  11. CHECK TURBOCHARGER SUB-ASSEMBLY


    1. Check that the turbine shaft rotates smoothly, without catching Click here.

    2. Check for loose turbine mounting nuts and for axial play in the turbine shaft Click here.

      Tech Tips

      If the turbine shaft catches or if there no play or excessive play, it could indicate poor sliding due to seal damage due to seizing or a deposit build-up.

      Standard value
      0.10 mm (0.00394 in.) or less
      Result:
      Result Proceed to
      No turbine shaft malfunction A
      Turbine shaft malfunction B

    B

    REPLACE TURBOCHARGER SUB-ASSEMBLY Click here

    A

  12. CHECK TURBOCHARGER SUB-ASSEMBLY


    1. Check for damage to the compressor impeller.

    2. Check for interference between the compressor impeller and the compressor housing.

      Result:
      Result Proceed to
      Damage or interference exists A
      No damage or interference B

    B

    CHECK TURBOCHARGER SUB-ASSEMBLY Click here

    A

  13. REPLACE TURBOCHARGER SUB-ASSEMBLY


    1. Replace the turbocharger sub-assembly Click here.


    NEXT

  14. PERFORM SIMULATION TEST


    1. Check that the abnormal noise has disappeared.


    NEXT

    END

  15. CHECK TURBOCHARGER SUB-ASSEMBLY


    1. Check for interference between the turbine wheel and the turbine housing.

      Result:
      Result Proceed to
      No damage or interference* A
      Damage or interference exists B

      Tech Tips

      Replace the turbocharger sub-assembly, as the abnormal noise may have been caused by interference between the turbine blades and housing.


    A

    REPLACE TURBOCHARGER SUB-ASSEMBLY Click here

    B

    REPLACE TURBOCHARGER SUB-ASSEMBLY Click here

  16. CHECK TURBOCHARGER SUB-ASSEMBLY


    1. Check that no soot or oil adheres to the turbocharger sub-assembly connectors.

      B001C9QE01

      Tech Tips

      If adhering soot or an oil leak exists, air leaking at that position may be the cause of the abnormal noise.

      Result:
      Result Proceed to
      No adhering soot or an oil* A
      Soot adhering around the turbine housing, flange, or V band (A in the illustration) B
      Oil leak from the contact surface between the compressor housing and bearing housing (B in the illustration) C
      Oil adhering to the compressor flange (C in the illustration) D

      Tech Tips

      *: Since abnormal noise may be the result of airflow noise from the blades, replace the turbocharger sub-assembly.


    B

    CHECK EXHAUST MANIFOLD CONVERTER SUB-ASSEMBLY Click here

    C

    REPLACE TURBOCHARGER SUB-ASSEMBLY Click here

    D

    REPLACE GASKET

    A

  17. REPLACE TURBOCHARGER SUB-ASSEMBLY


    1. Replace the turbocharger sub-assembly Click here.


    NEXT

  18. PERFORM SIMULATION TEST


    1. Check that the abnormal noise has disappeared.


    NEXT

    END

  19. CHECK EXHAUST MANIFOLD CONVERTER SUB-ASSEMBLY


    1. Check for deformation or cracks in the mounting surfaces on the exhaust manifold converter subassembly and the turbine with valve housing sub-assembly.

      Tech Tips

      Deformation or cracks on a mounting surface may allow exhaust gas to leak from the damaged position.

      Standard
      No deformation or cracks on a mounting surface
      Result:
      Result Proceed to
      No problem with the mounting surface A
      Deformation or cracks on the exhaust manifold converter sub-assembly mounting surface B
      Deformation or cracks on the turbine with valve housing sub-assembly mounting surface C

    B

    REPLACE EXHAUST MANIFOLD CONVERTER SUB-ASSEMBLY Click here

    C

    REPLACE TURBOCHARGER SUB-ASSEMBLY Click here

    A

  20. REPLACE EXHAUST PIPE CLAMP AND GASKET


    1. Replace the exhaust pipe clamp and the gasket.


    NEXT

  21. PERFORM SIMULATION TEST


    1. Check that the abnormal noise has disappeared.


    NEXT

    END

  22. CHECK TURBOCHARGER SUB-ASSEMBLY


    1. Check that the turbine shaft rotates smoothly, without catching Click here.

    2. Check for loose turbine mounting nuts and for axial play in the turbine shaft Click here.

      Tech Tips

      If the turbine shaft catches or if there no play or excessive play, it could indicate poor sliding due to seal damage due to seizing or a deposit build-up.

      Standard value
      0.10 mm (0.00394 in.) or less
      Result:
      Result Proceed to
      No turbine shaft malfunction A
      Turbine shaft malfunction B

    B

    REPLACE TURBOCHARGER SUB-ASSEMBLY Click here

    A

  23. CHECK TURBOCHARGER SUB-ASSEMBLY


    1. Check for damage to the compressor impeller.

    2. Check for interference between the compressor impeller and the compressor housing.

      Tech Tips

      If the previous checks find no malfunction, replace the turbocharger sub-assembly and determine if the noise improved.

      Result:
      Result Proceed to
      Damage or interference exists A
      No damage or interference B

    B

    CHECK TURBOCHARGER SUB-ASSEMBLY Click here

    A

  24. REPLACE TURBOCHARGER SUB-ASSEMBLY


    1. Replace the turbocharger sub-assembly Click here.


    NEXT

  25. PERFORM SIMULATION TEST


    1. Check that the abnormal noise has disappeared.


    NEXT

    END

  26. CHECK TURBOCHARGER SUB-ASSEMBLY


    1. Check for interference between the turbine wheel and the turbine housing.

      Result:
      Result Proceed to
      No damage or interference* A
      Damage or interference exists B

      Tech Tips

      Replace the turbocharger sub-assembly, as the abnormal noise may have been caused by loss of rotational balance and deterioration over time.


    A

    REPLACE TURBOCHARGER SUB-ASSEMBLY Click here

    B

    REPLACE TURBOCHARGER SUB-ASSEMBLY Click here