Seeing your spark plug wires glowing or "lighting up" is a serious issue that shouldn't be ignored. This indicates a significant problem in your vehicle's ignition system, potentially leading to engine damage or even a fire. This comprehensive guide will explore the causes, dangers, and solutions to this concerning automotive problem.
What Causes Spark Plug Wires to Light Up?
The most common reason for illuminated spark plug wires is high voltage leakage. This happens when the high voltage generated by the ignition coil isn't properly contained within the spark plug wires. This leakage can be caused by several factors:
- Worn or Damaged Wires: Over time, the insulation on your spark plug wires can degrade, crack, or become brittle. This allows the high voltage to escape, resulting in the visible glow. Cracks, especially near the spark plug boots, are a primary culprit.
- Faulty Spark Plug Boots: The rubber boots that connect the spark plug wires to the spark plugs themselves can also deteriorate. A cracked or loose boot will allow the voltage to arc to surrounding metal components.
- High Voltage Ignition System Issues: Problems with the ignition coil, distributor cap (in vehicles with distributors), or other ignition components can cause excessively high voltage, exceeding the capacity of the wiring insulation.
- Moisture or Contamination: Water, oil, or other contaminants on the spark plug wires or boots can significantly reduce the insulation's effectiveness, leading to arcing and glowing.
- Improper Routing of Wires: Incorrectly routed wires can rub against metal parts, causing wear and tear on the insulation.
Is it Dangerous to Drive with Glowing Spark Plug Wires?
Yes, absolutely. Driving with glowing spark plug wires is extremely dangerous for several reasons:
- Fire Hazard: The high voltage arcing can ignite flammable materials under the hood, leading to a potentially devastating engine fire.
- Engine Damage: Misfires caused by the voltage leakage can damage the engine's internal components, leading to costly repairs.
- Electrical System Damage: The uncontrolled voltage can damage other electrical components in your vehicle.
- Reduced Engine Performance: The misfires caused by the leaking voltage will severely impact your engine's performance, leading to poor acceleration, rough idling, and reduced fuel efficiency.
How to Fix Glowing Spark Plug Wires?
Addressing this issue requires a systematic approach:
- Visual Inspection: Carefully inspect all spark plug wires and boots for any signs of damage, such as cracks, wear, or corrosion. Replace any damaged components.
- Clean the Wires and Boots: Use a clean rag and a suitable degreaser (check your owner's manual) to thoroughly clean the wires and boots. Make sure they are completely dry before reinstalling.
- Check for Proper Routing: Ensure the spark plug wires are properly routed and aren't touching any metal parts.
- Inspect Ignition Components: If the problem persists, it may indicate a more serious issue within the ignition system. Consider having a professional mechanic diagnose and repair problems with the ignition coil, distributor cap, rotor, or other related components.
- Replace Spark Plug Wires: If the wires are old or show significant wear, replacing the entire set is the best solution. Opt for high-quality replacement wires from a reputable manufacturer.
What are the signs of bad spark plug wires?
Symptoms of bad spark plug wires can include misfires, rough idling, poor acceleration, difficulty starting the engine, and, of course, visible arcing or glowing. A comprehensive inspection is crucial.
How much does it cost to replace spark plug wires?
The cost to replace spark plug wires varies depending on the vehicle, the type of wire, and labor costs. Generally, you can expect to pay anywhere from a few tens of dollars for the parts to several hundred dollars for a professional mechanic to replace them.
Can I drive with a bad spark plug wire?
While you might be able to drive with a bad spark plug wire for a short distance, it's not recommended. Continued operation with a faulty wire risks engine damage, and the danger of fire is ever-present.
This detailed guide should provide the information needed to address the problem of glowing spark plug wires. Remember, safety is paramount; if you are uncomfortable performing any of these repairs, consult a qualified mechanic. Ignoring this issue could lead to serious and expensive consequences.
