Ignition Wire Set Replacement

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Learn about Ignition Wire Set Replacement from Wrench

Mobile Ignition Wire Set Replacement at Home or Office

As your spark plug wires age, they build resistance and do not transfer the electric pulse as well as they used to. This is mostly due to contact corrosion, and deterioration of the insulated coating or jacket on the wires. If the insulated coating on the ignition wires is cracked or torn the electric pulse may arc to other parts of your engine—causing a misfire. If the metal terminals become corroded there may be a loss of electrical power. This can result in abnormal flow of power to the spark plugs, which leads to incomplete combustion of the fuel-air mix in the cylinder. Incomplete combustion can cause engine misfires or stuttering, rough idling, power loss or power surges, and loss of fuel mileage. It also causes more harmful gasses to be passed on to the exhaust system, which might make your vehicle fail an emissions inspection. Misfires or emission problems may cause your check engine light to come on. If you don't know what to do, Wrench mobile mechanics provides towing and roadside assistance when there's no one there to help you.

What is Ignition Wire Set Replacement?

In many automobile engines, ignition cables connect a distributor, or ignition coil, to the spark plugs. The high voltage spark needed for combustion travels through these cables. These cables have a copper wire core wrapped in a silicon or rubber insulator several times thicker than the core. The copper interior may also be surrounded by shielding to prevent radio frequency interference. Each end of the cable has a clip meant to attach the cable to a spark plug or coil so that the cable will not become loose with engine vibration.

How is Ignition Wire Set Replacement Done?

  1. Allow your engine to cool for 3 to 4 hours before changing your spark plugs.
  2. If you plan to keep your original wireset, take the time to label each spark plug wire with masking tape and a marker.
  3. Remove each spark plug wire by pulling the boots to avoid breaking the wires.
  4. Check your vehicle repair guide to determine the necessary socket size and the correct gap for your spark plugs.
  5. Use a spark plug gapping gauge to achieve the specified gap on your new plugs.
  6. Be sure to use a spark plug socket with an internal gasket.
  7. Examine your spark plugs after you remove them for signs of mechanical problems.
  8. If your engine has aluminum cylinder head, you should use an anti-seize lubricant on the spark plug threads to prevent a negative reaction between the two different metals.
  9. Use a torque wrench to install your new spark plugs and tighten to the specifications given in your vehicle repair guide.
  10. If you are replacing your spark plug wires, consult your vehicle repair guide for a wiring diagram.
  11. Use a dielectric grease on the inside of each spark plug wire boot to ease removal in the future. Connect the spark plug wire boots to complete the job.


Make sure your vehicle is in a safe location, away from other traffic. If you're parked on the side of a road, make sure to turn your hazard lights on. If it's safe to do so, wait outside of your vehicle, behind guard rails. Be prepared, Wrench's towing and roadside assistance won't only solve most common issues, but also deliver peace of mind while you're on the road.

Symptoms That Indicate You Need An Ignition Wire Set Replacement

  • Rough engine idle
  • Reduced engine power
  • Engine surging

Contact us for an easy estimate, and protect your valuable vehicle.