NO. 21 Engine Noise: Notes

NO. 21 ENGINE NOISE (SKYACTIV-G 2.5T) DESCRIPTION AND POSSIBLE CAUSE

21	ENGINE NOISE
DESCRIPTION	Engine noise from under bonnet.
POSSIBLE CAUSE	Buzzing sound is heard from exhaust pipe during cold engine start: NOTE: During a cold engine start, sound occurs for up to approx. 30 s with fast idle up for a drive-by-wire control and the warm-up promotion spark retard correction for ignition timing control. Sound occurs from drive-by-wire control, ignition control (vehicle is normal) Dynamic damper loose Exhaust system installation condition Intake system installation condition Squeal, click, or chirp noise: Improper engine oil level Loose installation of solenoid valves Improper drive belt tension Generator installation Auto tensioner bearing malfunction Splash shield or under cover loose (splash water to drive belt) Thumping/rattling or creaking sound noise: Improper drive belt tension Loose parts Loose fitting heater hoses vibrating the heater hose bracket protector Hissing sound noise: Vacuum leakage Loose spark plug Air leakage from the intake-air system Clattering noise: Loose parts Lightly tapping or rumbling noise: Dynamic damper loose Exhaust system loose Intake-air system loose Excessive noise from turbocharger: Foreign objects or material in the compressor inlet to the intake manifold ducting or the compressor housing Carbon built-up in the turbine housing Turbocharger routing assembly banding or dragging Loose intake or exhaust ducting systems Other noise: Electric variable valve timing actuator malfunction Hydraulic variable valve timing actuator malfunction Timing chain noise Hydraulic lash adjuster (HLA) noise WARNING: The following troubleshooting flow chart contains the fuel system diagnosis and repair procedures. Read the following warnings before performing the fuel system services: Fuel vapor is hazardous. It can easily ignite, causing serious injury and damage. Always keep sparks and flames away from fuel. Highly pressurized fuel may spray out if the fuel line is cut. Due to the following dangers occurring with a fuel spray, always complete the "Fuel Line Safety Procedure" to prevent the fuel from spraying. (See Before Service Precaution .) Fuel may cause irritation if it comes in contact with skin and eyes. If fuel ignites and causes a fire, it may lead to serious injury or death, and damage to property and facilities. Fuel is highly flammable and dangerous. Fuel line spills and leakage can cause serious injury or death, and damage to equipment. Always refer to the "Quick Release Connector Removal/Installation (fuel system)" before performing the fuel hose installation, and execute the "Fuel Leakage Inspection" after installation. (See Quick Release Connector Removal/Installation .) (See After Service Precaution .) CAUTION: Disconnecting/connecting the quick release connector without cleaning it may possibly cause damage to the fuel pipe and quick release connector. Always clean the quick release connector joint area before disconnecting/connecting, and make sure that it is free of foreign material.

ENGINE NOISE

DESCRIPTION

Engine noise from under bonnet.

POSSIBLE CAUSE

Buzzing sound is heard from exhaust pipe during cold engine start:

NOTE:

During a cold engine start, sound occurs for up to approx. 30 s with fast idle up for a drive-by-wire control and the warm-up promotion spark retard correction for ignition timing control.

Sound occurs from drive-by-wire control, ignition control (vehicle is normal)
Dynamic damper loose
Exhaust system installation condition
Intake system installation condition

Squeal, click, or chirp noise:

Improper engine oil level
Loose installation of solenoid valves
Improper drive belt tension
Generator installation
Auto tensioner bearing malfunction
Splash shield or under cover loose (splash water to drive belt)

Thumping/rattling or creaking sound noise:

Improper drive belt tension
Loose parts
Loose fitting heater hoses vibrating the heater hose bracket protector

Hissing sound noise:

Vacuum leakage
Loose spark plug
Air leakage from the intake-air system

Clattering noise:

Loose parts

Lightly tapping or rumbling noise:

Dynamic damper loose
Exhaust system loose
Intake-air system loose

Excessive noise from turbocharger:

Foreign objects or material in the compressor inlet to the intake manifold ducting or the compressor housing
Carbon built-up in the turbine housing
Turbocharger routing assembly banding or dragging
Loose intake or exhaust ducting systems

Other noise:

Electric variable valve timing actuator malfunction
Hydraulic variable valve timing actuator malfunction
Timing chain noise
Hydraulic lash adjuster (HLA) noise

WARNING:

The following troubleshooting flow chart contains the fuel system diagnosis and repair procedures. Read the following warnings before performing the fuel system services:
- Fuel vapor is hazardous. It can easily ignite, causing serious injury and damage. Always keep sparks and flames away from fuel.
- Highly pressurized fuel may spray out if the fuel line is cut. Due to the following dangers occurring with a fuel spray, always complete the "Fuel Line Safety Procedure" to prevent the fuel from spraying. (See Before Service Precaution .)
Fuel may cause irritation if it comes in contact with skin and eyes.
- If fuel ignites and causes a fire, it may lead to serious injury or death, and damage to property and facilities.
  - Fuel is highly flammable and dangerous. Fuel line spills and leakage can cause serious injury or death, and damage to equipment. Always refer to the "Quick Release Connector Removal/Installation (fuel system)" before performing the fuel hose installation, and execute the "Fuel Leakage Inspection" after installation. (See Quick Release Connector Removal/Installation .) (See After Service Precaution .)

CAUTION:

Disconnecting/connecting the quick release connector without cleaning it may possibly cause damage to the fuel pipe and quick release connector. Always clean the quick release connector joint area before disconnecting/connecting, and make sure that it is free of foreign material.