Kia Optima DL3 Quiz
Engine Electrical System

Spark Plug

In this manual: Engine Electrical System
General Information — 8Advanced Driver Assistance System (ADAS) — 21Maintenance — 27Engine Mechanical System — 45Engine Electrical System — 11Emission Control System — 11Engine Control System/Fuel System — 25Automatic Transmission — 20Drive Shaft and Axle — 7Suspension System — 22Steering — 7Restraints — 11Brake System — 22Body (Interior and Exterior) — 116Body Electrical System — 90Heating, Ventilation, and Air Conditioning — 32
13steps
~78min
3/5difficulty
0102030405024.518N·mlb·ft
Tightening torque found on this page
Done 0 of 13

Description and Operation

Description

The spark plug delivers electrical current from the ignition system into the combustion chamber of a spark-ignition engine to ignite the compressed air/fuel mixture by means of an electric spark, while withstanding combustion pressure inside the engine. The spark plug has a threaded metal shell that is electrically insulated from the center electrode by a porcelain insulator.

Specifications

Specification

Item Specification
Type UNLEADED SILZKR7B11
LEADING SILZKR7B8
Gap UNLEADED 1.0 - 1.1 mm
(0.0393 - 0.0433 in.)
LEADING 0.7 - 0.8 mm
(0.0275–0.0314 in.)

Repair Procedures

Inspection

[When Inspecting the Vehicle]

  1. Race the engine to approximately 3000 rpm 3 or more times.

  2. Remove the spark plug.

  3. Visually inspect the spark plug.

    If the electrode is dry, the spark plug is in good condition.

    If the electrode is wet, check for damage and the electrode gap as shown below.

[Component Inspection]

  1. Check the spark plug for thread and insulator damage.

    If damaged, replace the spark plug.

  2. Check the electrode. Measure the insulation resistance with an ohmmeter.

    If the resistance is less than the specified value, adjust the electrode gap.

    Specification: 10 MΩ or more

  3. Check the spark plug electrode gap.

    If the gap is greater than the maximum, replace the spark plug.

    Specification: 1.0–1.1 mm (0.0394–0.0433 in.)

Cleaning

Combustion becomes temporarily unstable due to fuel aging and carbon deposits accumulated on the spark plug(s) after long-term storage.

[Method 1]

  1. Start the engine and let it idle for 2 minutes.

  2. Depress the accelerator pedal and hold the engine speed at 4500 rpm with the shift lever in N to warm up the engine until the engine coolant temperature reaches 80 °C.

  3. Run the engine at 2500–3000 rpm in N position for 15 minutes.

[Method 2]

  1. Start the engine and let it idle for 2 minutes.

  2. Drive the vehicle for more than 20 minutes while keeping engine speed above 3500 rpm.

Removal

  1. Remove the ignition coil.

    (Refer to Ignition System – Ignition Coil)

  2. Using a spark plug socket, remove the spark plug (A).

    Tightening torque: 14.7–24 N·m

Installation

  1. Install in the reverse order of removal.

Test yourself

A quick Kia Optima DL3 quiz: every answer comes with an explanation and a link to the manual page.