Click here

ECD SYSTEM (w/o DPF) Turbocharger Noise

Click here
Click here Click here
DTC Code DTC Name
  Turbocharger Noise
Click here

DESCRIPTION

Tip:

Turbocharger noise is classified into 2 types. One is whistling noise, and the other is whining noise. When troubleshooting, the type of noise should be determined first.

Table 1. Description
Noise Type Noise Description Main Trouble Area
Whistling noise The volume and pitch of this noise are proportional to turbocharger speed or engine speed. Therefore, the noise level will become more obvious when engine speed increases.

  • Turbocharger (e.g. shaft imbalance)

  • Gears inside engine

  • Transmission gear

  • Intake air system leakage

  • Intake air system breakage
Whining noise This noise has a lower pitch than whistling noise. It generally occurs in the engine speed range of 1500 to 2500 rpm, and has a relatively constant pitch, independent of engine speed and vehicle speed.

Turbocharger

Tip:

  • Example: Vibration of turbocharger is transferred to exhaust pipe which causes resonation and noise.

  • Example: Vibration of turbocharger is transferred through exhaust pipe to vehicle body (floor) which then vibrates causing noise.

Click here

  1. Faults and Symptoms of Diesel Engine Components

    Table 2. Turbocharger System
    Main fault Turbocharger turbine shaft imbalance
    Symptoms

    High-pitched whistling noise

    Tip:

    The pitch and volume change in proportion to the turbocharger speed.
    Table 3. Intake System
    Main fault Leakage
    Symptoms Leak flow noise
    Table 4. Gear inside Engine
    Symptoms

    Gear noise

    Tip:

    The pitch and volume change in proportion to the engine speed.
    Table 5. Transmission Gear
    Symptoms

    Gear noise

    Tip:

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

INSPECTION PROCEDURE

Click here

PROCEDURE


  1. Click here

    CONFIRM CONDITION IN WHICH NOISE OCCURRED


    1. Confirm with the customer the conditions in which the noise occurred.

      Tip:

      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 the noise to be abnormal?

  2. Click here

    CONFIRM NOISE CUSTOMER MENTIONED (PROCEDURE 2)


    1. Check for the noise described by the customer.

      Tip:

      If a noise is heard, make sure that the noise matches the noise described by the customer.

      Table 6. Result
      Result Proceed to
      Obvious abnormal noise matching noise described by customer is confirmed A
      Obvious abnormal noise matching noise described by customer is not confirmed B

  3. Click here

    CHECK INTAKE SYSTEM


    1. Check for air leakage between the air cleaner and turbocharger, and between the turbocharger and intake manifold.

      Tip:

      • Check for disconnected or improperly connected hoses, and gaps between hoses and parts.

      • Check for foreign matter between the air cleaner and turbocharger.


  4. Click here

    CONFIRM NOISE SOURCE (FROM TURBOCHARGER OR NOT)


    1. Connect the intelligent tester to the DLC3.

      Tip:

      The software version installed on the intelligent tester must be V2009.2 or later.

    2. Start the engine and warm it up.

    3. Turn the tester on.

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

      Tip:

      This Active Test function operates both the turbocharger actuators (bank 1 and bank 2) at the same time.

    5. Perform the Active Test and rev the engine up several times.

    6. Check whether the noise is reduced or not compared with the noise under the condition that the Active Test is not performed.

      Table 7. 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
      Tip:

      • When the variable nozzle of the turbocharger opens fully regardless of the engine condition, the turbocharger speed slows down and the cause of noise can be confirmed that is from the turbocharger or not.

      • If the turbocharger is the cause of the noise, the noise will be reduced when the variable nozzle opens because turbocharger speed does not increase.


  5. Click here

    CONFIRM THE NOISE TYPE (PROCEDURE 5)


    1. Check whether the noise can be heard even when the engine speed is more than 3000 rpm, and whether the noise gradually gets louder as the engine speed increases.

      Tip:

      If so, the noise is likely to be whistling noise. If not, the noise is likely to be whining noise.

    2. If whistling noise is confirmed on the above inspection, identify the malfunctioning turbocharger (No. 1 or No. 2) using a sound scope.

      Table 8. Result
      Result Proceed to
      Yes (The noise is likely to be whistling noise) A
      No (The noise is likely to be whining noise) B

  6. Click here

    REPLACE TURBOCHARGER SUB-ASSEMBLY (NO. 1 OR NO. 2)


    1. Replace either No. 1 or No. 2 turbocharger sub-assembly which is on the malfunctioning bank confirmed in procedure 5 (Click here).


  7. Click here

    CONFIRM WHETHER THE NOISE PROBLEM HAS BEEN SUCCESSFULLY SOLVED


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


  8. Click here

    PERFORM ALIGNMENT OF EXHAUST PIPE AND CONFIRM THE NOISE


    1. A015AM9E02

      Disconnect the exhaust pipe at the ball joint and from each exhaust pipe support, and then realign the exhaust pipe and reconnect it to each exhaust pipe support and at the ball joint (Click here).

      Table 9. Text in Illustration
      *1 Gasket *2 Monolithic Converter Assembly RH
      *3 Compression Spring *4 Front No. 1 Exhaust Pipe Assembly
      *5 Monolithic Converter Assembly LH *6 Front No. 2 Exhaust Pipe Assembly
      *7 Center Exhaust Pipe Assembly *8 Exhaust Pipe Support
      *9 Clamp *10 Tail Pipe Assembly
      *a Specified torque *b Non-reusable part
      Tip:

      Above illustration is an example.

    2. Confirm whether the noise problem is solved or not.

      Tip:

      The alignment of the exhaust pipe affects whining noise.

      Table 10. Result
      Result Proceed to
      The noise problem is solved A
      The noise problem remains

      B*
      Tip:

      *: If the noise problem still remains, replace both the No. 1 and No. 2 turbocharger sub-assembly.


  9. Click here

    CHECK FOR NOISE FROM SOURCE OTHER THAN TURBOCHARGER (PROCEDURE 9)


    1. A015COCE01

      Check for the noise source with a sound scope.

      Note:

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

      Tip:

      • 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).

      • 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.

      • The following illustration is a reference for checking whether the noise source is from the engine.

      Table 11. Text in Illustration
      *1 Supply Pump Drive Gear *2 Camshafts
      *3 Crankshaft *4 Oil Pump
      *5 Scavenging Pump *6 Turbocharger
      *a Gear Location inside Engine - -
      Tip:

      • Above illustration is an example.

      • Gear noise can be confirmed with a sound scope. Put the sound scope on the cylinder block near the gear, and if the noise heard through the sound scope has the same timing as the noise heard without the sound scope, it is gear noise.


  10. Click here

    REPLACE THE PARTS DETECTED IN PROCEDURE 9


    1. Replace the parts detected in Procedure 9 as the noise source.


  11. Click here

    CONFIRM WHETHER THE NOISE PROBLEM HAS BEEN SUCCESSFULLY SOLVED


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


  12. Click here

    EXPLAIN TO THE CUSTOMER THAT THE NOISE IS NORMAL


    1. Explain to the customer that the noise the customer mentioned is not abnormal.

      Tip:

      To help the customer understand, test driving another car with the customer may be helpful.


  13. Click here

    REPAIR OR REPLACE MALFUNCTIONING PARTS

  14. Click here

    REPLACE TURBOCHARGER SUB-ASSEMBLYClick here

  15. Click here

    END