Turbocharger Noise [10/2015 - ]: Description

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HINT:

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

Type of Abnormal Noise	Outline of Abnormal Noise	Major 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 HINT: 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.

Type of Abnormal Noise

Outline of Abnormal Noise

Major 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

HINT:

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.

Faults and Symptoms of Diesel Engine Components

TURBOCHARGER SYSTEM

Main fault	Unstable turbocharger turbine shaft (interference, seizing, poor balance, etc.) Poor installation or defective operation of the waste gate valve. Poor installation or defective operation of the air by-pass valve assembly.
Symptom	High-pitched whistling sound HINT: The volume and pitch are proportional to the turbocharger speed. Metallic sound due to looseness

INTAKE SYSTEM

Main fault	Leak
Symptom	Abnormal noise during intake leak

TRANSMISSION GEARS

Symptom

Gear noise
HINT:
The volume and pitch are proportional to the transmission gear speed.