Ford Spark Plug | Ignition Coil Replacement | 4-Cylinder Engine

DIY Cost: $20-65
Est. Time: 1-2 hr
Difficulty: Intermediate
This guide provides instructions on how to change spark plugs and ignition coils on the Ford 4-cylinder 2.0l engine.

The four-cylinder engine is found on Ford S-Max, Ford C-Max Mk I, Ford Mondeo Mk III, Mk IV, Ford Focus Mk II, and also on Mazda 3, Mazda 5, Mazda 6, Ford Galaxy Mk III.

What you will need


  1. Park the vehicle and allow the engine to cool down. Remember to set the parking brakes. Pull the hood release and open the hood.
  2. Remove the engine cover.
  3. Unplug all the electrical connectors from the ignition coils.unplug ford ignition coil
  4. Remove the 10 mm bolts that hold the ignition coils. Remove the ignition coils by pulling them up.
  5. Use a spark plug socket, extension, and ratchet to remove the spark plugs.remove ford focus spark plugs
  6. Install the new spark plugs. Carefully lower the spark plugs into the engine. Don't allow the spark plugs to drop because the gap of the spark plug may be affected. Torque the spark plugs to specification.
  7. Install the ignition coils and electrical connectors.install ignition coil
  8. Reinstall the engine cover.
  9. Start the vehicle and check to ensure the engine is running smoothly.

Torque Specifications

Torque for spark plugs varies depending on the spark plug thread size and gasket type.

Typical values:

  • 14 mm spark plugs: 8-15 lb. ft.
  • 18 mm spark plugs: 15-20 lb. ft.

Tightening spark plugs with a torque wrench is recommended. If you are installing spark plugs without a torque wrench, tighten them until they are snug tight plus an extra 1/8 to 1/4 turn.


  • Check engine light on
  • Car overheats
  • Reduced power
  • High fuel consumption
  • Engine shakes
  • Engine runs rough

Spark Plug Gap

Ford spark plug gap can range from 0.036" to 0.050".

A new spark plug should be pre-gaped for your engine. Verify the correct spark plug gap by looking it up in your owner's manual or by calling your Ford or Mazda dealer parts department.

Do not gap the new spark plugs based on the gap of the old spark plugs. The old plugs will have a bigger gap due to spark plug wear.

Spark Plug Replacement Interval

The spark plug replacement interval is directly correlated to the type of spark plug installed on your car.

Typical spark plug replacement intervals:

  • Copper: 30,000-50,000 miles
  • Platinum: 60,000-100,000 miles
  • Iridium: 100,000-120,000 miles

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Ford Spark Plug | Ignition Coil Replacement | 4-Cylinder Engine What you will need Ford Spark Plugs Ford Ignition Coils (optional) Spark Plug Socket 3/8" Ratchet wrench 3/8" 6-inch extension