Why One Ignition Coil Failure Often Signals More Trouble

A subtle misfire at idle can be the first sign of a larger ignition system issue, especially on Chrysler’s popular Pentastar engine. In this Tech Tip, Noah Nelson, Motor Age technical editor, walks technicians through a real-world diagnostic scenario involving a Pentastar 3.6 misfire diagnosis and explains why a single coil failure often signals a broader problem. 

As Nelson explains, the Pentastar engine design requires removing the intake plenum to access the driver-side coil bank. Because all six coils share the same heat cycles, vibration exposure and mileage, a failure in one component often indicates that the others are approaching the same end-of-life point. Instead of replacing coils one at a time and repeating the same labor-intensive repair, Nelson recommends a preventive ignition coil replacement strategy to restore consistent spark performance across all cylinders. 

The video also dives into the technical side of automotive misfire diagnostics, including how worn spark plugs increase voltage demand and accelerate ignition coil failure symptoms such as weak spark, cold-start hesitation and intermittent misfire counters. Nelson also discusses how OE-quality Chrysler Pentastar ignition coils ensure proper dwell control and reliable performance. 

If you want practical insight into a smarter ignition coil replacement strategy and avoiding repeat repairs, watch the full Tech Tip to see how professional technicians diagnose and solve these common misfire problems.