WHEN TO REPLACE IGNITION COILS

Ignition coils are the critical link between the battery and the combustion chamber. They are high-precision transformers designed to convert low voltage into the high-intensity spark required for operation. When these components are worn down, engine efficiency drops, which leads to strain on the equipment and increased emissions. 

Knowing when to replace ignition coils is the difference between scheduled maintenance and an emergency repair, which can lead to costly downtime and more issues for your equipment. 

Signs Ignition Coils Need to be Replaced Soon

• Thermal degradation: The constant operation at high temperatures breaks down the epoxy resin and internal copper windings.
• Secondary voltage stress: If spark plugs aren’t gapped correctly or are past their prime, the coil must work harder to jump the gap, leading to internal “arcing” or insulation breakdown.
• Vibration fatigue: Heavy-duty applications cause physical wear on the connectors and housing, eventually requiring a full change. 

When an Emergency Ignition Coil Change is Required

Look for these specific indicators of coil failure before they lead to catastrophic engine damage:

• Intermittent misfiring: Often more noticeable under heavy load or high torque requirements.
• Carbon tracking: Visual signs of electrical leakage on the coil boot or tower.
• Increased emissions: A weak spark leads to incomplete combustion, which can foul oxygen sensors and ruin catalytic converters.
• Diagnostic Trouble Codes (DTCs): Modern industrial controllers will often throw codes for “Coil Primary/Secondary Circuit Malfunction” before a total failure occurs. 

Recommended Replacement Intervals

While many ignition systems are designed for longevity, a proactive change is recommended every 60,000 to 100,000 miles or 5 years of service. For equipment operating in extreme environments or high-duty cycles, we recommend a more frequent replacement schedule to maintain peak engine calibration.

Note: When performing a replacement, it is best practice to change the spark plugs simultaneously. Worn plugs are the leading cause of premature coil failure.

Looking to replace your coils or other parts of your ignition? Improve your equipment’s performance with our wide selection of ignition parts and accessories on our e-commerce site.