ECD SYSTEM > Turbocharger Noise |
| 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. |
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| 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
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| Faults and Symptoms of Diesel Engine Components |
| Main fault | Turbocharger turbine shaft imbalance | |
| Symptoms | High-pitched whistling noise
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| Main fault | Leakage | |
| Symptoms | Leak flow noise | |
| Symptoms | Gear noise
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| Symptoms | Gear noise
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| 1.CONFIRM CONDITION IN WHICH NOISE OCCURRED |
Confirm with the customer the conditions in which the noise occurred.
| Item | Note |
| Engine speed | Engine speed range |
| Vehicle speed | Vehicle speed range |
| Transmission gear | Which gear? |
| Accelerator pedal position | During acceleration or deceleration? |
| Temperature |
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| Road conditions |
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| Noise level |
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| Other symptoms |
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| Noise recognition | What made the customer determine the noise to be abnormal? |
| NEXT | |
| 2.CONFIRM NOISE CUSTOMER MENTIONED (PROCEDURE 2) |
Check for the noise described by the customer.
| 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 |
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| A | |
| 3.CHECK INTAKE SYSTEM |
Check for air leakage between the air cleaner and turbocharger, and between the turbocharger and intake manifold (Click here).
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| OK | |
| 4.CONFIRM NOISE SOURCE (FROM TURBOCHARGER OR NOT) |
Connect the intelligent tester to the DLC3.
Start the engine and warm it up.
Turn the tester on.
Enter the following menus: Powertrain / Engine and ECT / Active Test / Activate the VN Turbo Open.
Perform the Active Test and rev the engine up several times.
Check whether the noise is reduced or not compared with the noise under the condition that the Active Test is not performed.
| 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 |
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| A | |
| 5.CONFIRM NOISE TYPE |
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.
| Result | Proceed to |
| Yes (The noise is likely to be whistling noise) | A |
| No (The noise is likely to be whining noise) | B |
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| A | ||
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| 6.PERFORM ALIGNMENT OF EXHAUST PIPE AND CONFIRM THE NOISE |
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).

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*1 | Exhaust Manifold Converter Sub-assembly |
*2 | Tail Exhaust Pipe Assembly |
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*3 | Exhaust Pipe Support | - | - |
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*a | Boll Joint | - | - |
Confirm whether the noise problem is solved or not.
| Result | Proceed to |
| The noise problem is solved | A |
| The noise problem remains | B |
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| A | ||
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| 7.CHECK FOR NOISE FROM SOURCE OTHER THAN TURBOCHARGER (PROCEDURE 7) |
Check for the noise source with a sound scope.

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*1 | Vacuum Pump |
*2 | Camshafts |
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*3 | Supply Pump |
*4 | Chain Tensioner Slipper |
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*5 | Chain Sub-assembly |
*6 | Chain Vibration Damper |
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*7 | Oil Pump |
*8 | No.2 Chain Sub-assembly |
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*a | Gear Location inside Engine | - | - |
| NEXT | |
| 8.REPLACE THE PARTS DETECTED IN PROCEDURE 7 |
Replace the parts detected in Procedure 7 as the noise source.
| NEXT | |
| 9.CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED |
Check whether the noise problem has been successfully solved.
| NEXT | ||
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| 10.EXPLAIN TO THE CUSTOMER THAT THE NOISE IS NORMAL |
Explain to the customer that the noise the customer mentioned is not abnormal.
| NEXT | ||
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