← Lacetti Chevrolet Lacetti repair manuals →
Autopapyrus · Chevrolet Lacetti 1.4 F14D3 (2006)
https://autopapyrus.com/guides/chevrolet/lacetti/checking-and-replacing-the-spark-plug-wires/
Compiled automatically from service literature and owner experience. Specs are for the typical configuration — check them against your exact car before you start.

Chevrolet Lacetti 1.4 F14D3 (2006): Checking and Replacing the Spark Plug Wires

The spark plug wires carry the pulse from the ignition coil to the spark plugs. With age, the insulation cracks, resistance rises and the wires start to arc. Symptoms: rough running (misfire), fluctuating idle, hesitation under acceleration, misfire codes, and the Check Engine light coming on. Do the work on a cold engine that is turned off. Replace the wires one at a time so you don't mix up the firing order.

Difficulty: Easy Time: 30-60 minutes Steps: 13 Tools: spark plug socket (16 mm or 21 mm, to match the plugs), extension with a universal joint, multimeter (ohmmeter mode), clean dry rag, dielectric silicone grease, marker or masking tape for labeling

Part

  • 🔩 Spark plug (high-voltage) wire set for Lacetti 1.4 (F14D3), 4 wires. Make sure you get a set made specifically for the 1.4: wire lengths for the 1.4, 1.6 and 1.8 versions may differ. It's a good idea to replace the spark plugs at the same time if they have more than 30,000 km (about 18,600 miles) on them
There's a full repair manual for this car Every system, wiring diagrams and torque specs — not just this job. Haynes AutoFix (online). See manuals →

Step by step

13 steps
  1. Turn off the engine and let it cool down. Open the hood and remove the decorative plastic engine cover, if fitted.
  2. Inspect the wires with the engine running, preferably at dusk. Arcing looks like sparks or crackling on the insulation, near the boots and near the coil. Do not touch the wires with your hands and do not spray water on them: the voltage is dangerous, and water gives a misleading picture.
  3. Turn off the engine. Inspect the wires for cracks, melting, oil stains, chafing against engine bay parts, and corrosion of the contacts inside the boots.
  4. Measure the resistance of each wire with a multimeter between the contacts at its ends. For silicone wires with a conductive core, a rough guideline is about 0.5 to 10-12 kΩ per wire. A reading noticeably above the factory value, an open circuit, or a large spread between wires means the set needs to be replaced. For the exact acceptable value for your particular set, check the packaging.
  5. Label the wires (cylinders are counted from the timing belt side) and take a photo of the routing. Remove and replace them strictly one at a time.
  6. Remove the boot from the spark plug end by gripping the plastic boot and twisting it back and forth, not by pulling on the wire itself. Never pull on the wire: the conductive core will break. If the boot is stuck, carefully turn it with pliers or a screwdriver through the boot.
  7. In the same way, disconnect the other end of the wire from the output tower of the ignition coil (an ignition module with two coils). The coil outputs are usually marked or numbered by cylinder.
  8. Before installing the new wire, blow out and wipe the spark plug well. That way no dirt gets into the cylinder if you are also replacing the plugs. Check the condition of the plugs and compare it with the norm: light brown deposits mean normal operation, while black dry soot or oil points to other problems.
  9. Apply a thin layer of dielectric silicone grease to the inside of the new wire's boots. Then push it onto the spark plug and onto the coil output until it clicks or you feel it seat firmly. The wire must fit tightly, with no play.
  10. Route the wire in its original position, without tension. It must not touch the exhaust manifold or moving parts, and the clips and holders must be put back in place.
  11. Repeat the procedure for the other three wires, one at a time. Then check against the photo and labels to make sure the order has not been changed.
  12. Install the engine cover, start the engine and let it idle for 3-5 minutes. The engine should run smoothly, with no vibration or rough running. Listen for crackling around the wires. Check that the Check Engine light is off.
  13. If the engine still runs rough after the replacement, check the spark plugs, the ignition coil (module), the injectors and the compression. The cause may not be the wires.

Common mistakes and warnings

  • Do not work on the wires while the engine is running and do not touch them: the voltage in the ignition system is dangerous, especially for people with a pacemaker. Do not pull on the wire itself, only on the boot. Do not replace all the wires at once without labeling them: a mixed-up firing order will cause misfires, and a backfire into the intake is possible. Cheap wires with no resistance marking often cause radio interference and fail early, so buy a set from a well-known manufacturer.