Installing new plug wires

Ignition wires, or spark plug wires ... or just 'plug wires', as they are commonly referred, last a long time. But over time their conductive cores which the carry high voltage electricity to the spark plugs become degraded and should be changed to avoid problems. It's difficult to determine when ignition wires should be changed but most manufacturers recommend every 50,000 - 100,000 miles. Changing the plug wires is an easy and inexpensive maintenance task just about anyone can do. Basically what’s involved is removing each of your vehicle’s existing plug wires one at a time and replace each with a new one of the proper length. That's it! Follow along as we show you exactly how to do it.

The steps:

1) Remove a spark plug wire from the engine.
Remove and replace one wire at a time beginning with the longest wire first. Firmly grasp the boot that is attached to the distributor (top of engine) and firmly pull the wire straight off using a steady pull. If the wire seems to be stuck, firmly twist the plug wire back/fourth until it loosens. Then remove the other end of the same wire from the spark plug (about half way down the side of the motor). Pay close attention to how the wire is routed before removing the wire from the engine.

2) Match old wire to new wire
Select the wire from the set of new plug wires that matches the length of the wire you are replacing. Double-check that the ends of the new wire match the ends of the old wire.

3) Install new wire
Route the new spark plug wire through the same path as the old wire. Take care that the new wire is securely fastened to all necessary clips and holders and is not touching any hot or moving parts. Push the appropriate end of the new wire onto the spark plug - you should feel or hear a faint “click” as the terminal snaps into place. Take care to ensure that the metal terminal is correctly seated over the spark plug end and not to the side of the spark plug tip. Push the other end of the new spark plug wire onto the distributor cap (or distributor block) until firmly seated. Take special car that the metal terminal inside the boot goes deep into the distributor.

5) Repeat the above steps until all wires are replaced.

6) Double check wire routing.
Reroute any wires that rub or contact linkages or any moving part including suspension components. Also make sure wires are not touching excessively hot components such as exhaust manifolds. Double-check that the spark plug wire boots are securely fastened at both the spark plug and distributor.

Never work near an engine when it is warm or hot! Besides the obvious that you might burn yourself, most modern engines use electric cooling fans which can, and often do, come on even after an engine has been shut off. Let the engine cool for an hour before working around it. For added protection remove the negative battery cable.