Inspection Procedure 12: Abnormal sound occurs during driving.


PROBABLE CAUSES



  • Engine- and body-related failures: Abnormal sound of auxiliary parts, drive shaft, wheel bearing
  • Installation of non-genuine aeroparts to the body
  • Abnormal incoming route of sound: Installation of transmission control cable, damping device, sound isolation device
  • Malfunction of the torque converter
  • A/T failure: Driving force transmission system (gear), hydraulic system (valve body assembly, hydraulic circuit)
note Inspection items for abnormal sound
  1. Check of sound source and incoming route (radiated sound, propagation sound, resonance, etc.), and measurement at driver’s seat, front passenger’s seat, and rear passenger’s seat
  2. Change of sound during cold and after warm up (Change of fluid, and hydraulic pressure)
  3. Change of sound with the engine speed (r/min order change)
  4. Change of sound with the vehicle speed (r/min order change, wind noise)
  5. Change of sound with the throttle valve opening (engine output change, hydraulic pressure change)

DIAGNOSIS PROCEDURE

STEP 1. Check the body and engine performance.

  • Check if a non-genuine aeropart is installed to the body.
  • Check the engine auxiliary parts, drive shaft, and wheel bearing.
  • Check if the abnormal sound changes in accordance with the engine speed, or the vehicle speed.

Q. Is the check result normal?
Go to Step 2.
Repair the failure, and perform adjustment.

STEP 2. Check the installation of the transmission control cable, damping device, and sound isolation device.

Q. Is the check result normal?
Go to Step 3.
Repair the failure, and perform adjustment.

STEP 3. Check the abnormal sound.

Q. Does the abnormal sound change in accordance with the vehicle speed?
Go to Step 5.
Go to Step 4.

STEP 4. Check the abnormal sound.

Q. Does the abnormal sound change in accordance with the throttle valve opening? Or is it the A/T fluid sound especially caused at start-up?
Replace the torque converter.
Go to Step 5.

STEP 5. Compare with another same model vehicle.

Q. Is there a difference from the same model vehicle?
Go to Step 6.
The procedure is complete.

STEP 6. Remove the transmission assembly from the vehicle.
Disassemble and check the transmission assembly to check if there is a foreign material inside.

Q. Is the check result satisfactory?
Replace the transmission assembly.
Replace the failure part.