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Home >> Kia >> 2018 >> Optima Plug-In Hybrid EX >> Repair and Diagnosis >> Engine Performance >> Ignition System >> Ignition System (PHEV) >> Spark Plug >> Repair Procedures >> Cleaning
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Repair Procedures: Cleaning

The combustion temporarily becomes unstable, due to the aged fuel and the carbon deposits accumulated on the spark plug(s) after long-term storage.

[1st Method] 

  1. Start the engine and keep the engine running at idle for 2 minutes.
  2. Step on the accelerator pedal and hold it steady at 4500 RPM with the shift lever in N position to warm up the engine until the temperature of the engine coolant reaches 80°C.
  3. Keep the engine running at 2500 - 3000 RPM in the N position for 15 minutes.
G12347125Courtesy of KIA MOTORS AMERICA, INC.

[2nd Method] 

NOTE: The 2nd method should be performed only if the 1st method fails (the misfire-related codes recur).
  1. Start the engine and keep the engine running at idle for 2 minutes.
  2. Drive the vehicle for over 20 minutes, keeping the engine speed above 3500 RPM.
    NOTE: If equipped with manual transaxle, shift the gear properly for keeping the engine speed above 3500 RPM.
    G12347126Courtesy of KIA MOTORS AMERICA, INC.