How to Change Your Spark-Plug Wires

A bad spark-plug wire can keep your car from running well or starting at all. You should replace the spark-plug wires every 30,000 miles (50,000 km), although a tune-up won't necessarily include this service. Unless you have asked for them to be replaced, your car's spark-plug wires may be quite old.

Difficulty: Moderately Easy

Instructions

Things You'll Need:

• Spark-plug Wire Puller
• Spark-plug Wire(s)

1. Purchase a set of spark-plug wires at an auto-parts store. It is also possible to buy a single wire if only one needs replacing.

2. 

   Look under the hood to find the spark-plug wires.

3. Pull off one spark-plug wire at a time by grasping it at the base of the wire. Use a spark-plug wire puller or just your fingers.

4. Match it up by length with a new plug wire. Each spark-plug wire is a specific length, so make sure to replace the wire with one of exactly the same length.

5. Attach the new wire to the spark plug on one end and to the distributor cap on the other end. Listen for a small click or pop as you connect the wire.

6. Repeat steps 3 through 5 for all the other plug wires.

7. Replace the coil wire (if your car has one). This is the wire that goes from the middle of the distributor cap to the coil. Use the same method as for replacing the other plug wires.

Tips & Warnings

• Spend the extra money for a good-quality set of sparkplug wires. Cheap ones are not worth the effort of installation; they will fail early, creating performance problems.
• Do not disconnect the sparkplug wires all at once. Take them off and replace them one at a time so you don't mix up their order.

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on 11/22/2005 When you replace any spark plug wires, it's better to replace all of them at once, even if the others seem fine. This makes maintenance a lot easier.