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Spark Plug: Troubleshooting

WARNING:
  • When working on high voltage system, the work should be performed out by technicians who have completed the relevant training. A lack of understanding of high voltage system can lead to serious accidents due to electric shock or short circuit.
  • When working on high voltage system or related components, be sure to be familiar with and comply with the "HIGH VOLTAGE SYSTEM GENERAL SAFETY INFORMATION AND CAUTION ." Failure to comply can lead serious accidents due to electric shock or short circuit.
  • When working on the high voltage system, make sure to check the Personal Protective Equipment (PPE) and high voltage shut-off procedure
  1. Check the DTC code by using the KDS (Refer to "DTC guide").
    G15766889Courtesy of KIA MOTORS AMERICA, INC.
  2. Check the connection condition of the ignition coil connectors (A).
    G15766890Courtesy of KIA MOTORS AMERICA, INC.
  3. Check the installation condition of the ignition coils (A).

    Tightening torque: 

    9.8 - 11.8 N.m (1.0 - 1.2 kgf.m, 7.2 - 8.7 lb.ft)

    G15766891Courtesy of KIA MOTORS AMERICA, INC.
  4. Remove the spark plug.

    (Refer to Spark Plug - "REMOVAL AND INSTALLATION ")

  5. Visual inspection of the spark plugs.

    Spark plug electrode gap:  1.0 - 1.1 mm (0.039 - 0.043 in.)

    Symptom Suspected Cause Correction
    G15766892Courtesy of KIA MOTORS AMERICA, INC.

    Melting Electrode    		 Abnormal Combustion, Overheat Replace the Spark Plug
    G15766893Courtesy of KIA MOTORS AMERICA, INC.

    Carbon and Foreign Matter
    G15766894Courtesy of KIA MOTORS AMERICA, INC.

    Ring Crack    		 Abnormal Combustion, External Shock
    G15766895Courtesy of KIA MOTORS AMERICA, INC.

    Vertical Crack    		 External Shock
    G15766896Courtesy of KIA MOTORS AMERICA, INC.

    Overheat    		 Abnormal Combustion
    Symptom Suspected Cause Correction
    G15766897Courtesy of KIA MOTORS AMERICA, INC.

    Poor Gap    		 Physical Damage Replace the Spark Plug
    G15766898Courtesy of KIA MOTORS AMERICA, INC.

    Flash Over    		 Excessive Electrode Wear Replace the Spark Plug, Ignition Coil
    G15766899Courtesy of KIA MOTORS AMERICA, INC.

    Corrosion/Rust    		 Remaining Oil Mist Reassemble the Spark Plug
  6. Check the resistance between the spark plugs terminal (A) and probe (B) by using a multi-tester or a resistance meter.

    Specified value:  2 - 20 kΩ

    G15766900Courtesy of KIA MOTORS AMERICA, INC.
    NOTE:
    • Avoid the contact resistance between probe and spark plugs (when it occurs, the measured value is not stabilized).
    • Be careful not to damage center electrode (A) while measuring resistance.
    G15766901Courtesy of KIA MOTORS AMERICA, INC.
  7. Test for changing position of each ignition coil and spark plug.
  1. Remove the spark plug (A) and ignition coil (B) from the misfiring cylinder and exchange them with one of the other cylinders.

    (Refer to Spark Plug - "REMOVAL AND INSTALLATION ")

    G15766902Courtesy of KIA MOTORS AMERICA, INC.
  2. Replace the spark plugs, if misfire moves along the spark plugs.
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