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Engine Noise: Notes

ENGINE NOISE (VINs 7, L, M), US) DESCRIPTION AND POSSIBLE CAUSE

Troubleshooting item Engine noise
Description
  • Engine noise from under hood.
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

Pulsing sound is heard:
  • Exhaust shutter valve malfunction (With cylinder deactivation)

Lightly tapping or rumbling noise:
  • Dynamic damper loose
  • Exhaust system loose
  • Intake-air system loose

Other noise:
  • Electric variable valve timing actuator malfunction
  • Hydraulic variable valve timing actuator malfunction
  • Timing chain noise
  • Hydraulic lash adjuster (HLA) noise
Possible cause
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 [(VIN M)] .) (See BEFORE SERVICE PRECAUTION [(VIN 7 & VIN L)] .)
  • 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.
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.
System wiring diagram
  • Not applicable
Connector diagram
  • Not applicable