Unlocking Peak Engine Performance

Unlocking Peak Engine Performance

Unveiling the truth about ignition systems and engine performance optimization. Sponsored by The Group Training Academy.


When an engine is designed, each cylinder is perfect. Each is an exact copy of its neighbor. The components within the engine are designed to be equal as well – injectors, spark plugs and ignition coils are engineered to function the same, regardless of which cylinder they serve.

With all the cylinders the same, the engine is balanced. Of course, this also means that all the coils are subjected to equal heat and vibration under the vehicle’s hood. If the engineers use a balanced approach in designing the engine’s ignition system, why would you use an unbalanced approach to repair it?

Equally matched cylinders, combustion chambers and ignition components are easily created on the engineer’s computer, but in the real world, balance isn’t so easily achieved. It is not uncommon for one coil to fail and cause a diagnostic trouble code like P0301 for a specific cylinder misfire or for the ignition circuit like a P0351, indicating a malfunction or open in the primary side of the coil.

The fact is, the engine compartment is no place for the weak. It’s a rough environment for any component. Specifically, heat and vibration can break down the epoxy resin that holds the primary and secondary windings. Even the coil windings can be damaged by heat and vibration – this is one of the most common causes of these codes.

There are two practices some technicians use that can cause more ignition system problems than they solve. The first bad practice is swapping coils to isolate a misfire. The second practice is to replace coils one by one as they fail.

Both practices originated in the era of points and distributors when ignition systems were analog and not digital. Swapping coils was common because many coils were the same for most vehicles. You could take a “known good” coil from another vehicle to see if the problem was the coil.

Theoretically, this diagnostic practice works because, if a coil is not functioning, it will cause a misfire no matter what cylinder it is connected to – but this diagnostic approach does not take into account how the primary side of the coil is turned on and off.

It may be tempting to replace only one coil at a time to save some money, but while replacing one coil might cure the misfire and codes for now, the other coils could fall prey to the same failure and codes. This is why ignition coil manufacturers package coils in sets and recommend complete replacement for best performance.

On millions of popular engines, you must remove the intake manifold to gain access to the ignition coil. This adds additional effort and labor time to what can be a simple job – the best solution for your time and your customer’s piece of mind is to replace all of the car’s coils at the same time. Of course, properly performing and documenting the repair along with clearly stating the reason for your recommendations is always the right procedure.

And to maintain perfect balance, remember that spark plugs typically wear at the same rate as the coil. As the gaps increase, the voltage required from the coil also increases. Not replacing the plugs with today’s high-ignitability spark plug could leave the original cause of the coil failure in the engine. By renewing the plugs with the coils, you can assure the customer that the problem has been solved.

For more information visit NGKSparkPlugs.com.

Thanks for watching!

You May Also Like

EV Safety Basics on the Shop Floor – Part I

It’s critical to utilize OEM service information and procedures for each and every hybrid or EV.

Electric vehicle safety — it’s a topic that’s on a lot of our minds. High voltage can be frightening because it can kill, but it shouldn’t scare you away. The reality is EV technology is a safe technology. As long as you understand it, respect it, and follow established safety guidelines for EV service. Let’s look at how to establish safety basics in your shop.

Autel MaxiSYS Ultra Enhances Efficiency At Mighty Auto Pro

Time is money in vehicle repair, and the Autel MaxiSYS Ultra is all about enhancing technicians’ diagnostic prowess.

Empowering the Automotive Aftermarket Through Collaboration

Distributors, manufacturers, training institutions, associations and service providers all help automotive professionals stay ahead in a market that is constantly evolving with new technologies, trends and customer demands.

Understanding LSPI & Engine Oil

Using the correct manufacturer-recommended oil is crucial for peak performance and long-lasting engine health.

Randy Breaux, Group President, GPC North America, Talks to AMN Drivetime

At NAPA, “Breaux Knows” business relationships, ABCs to avoid, and serving the automotive professional.

Other Posts
Serpentine Belt and Drive System Maintenance

Properly maintaining the entire drive system prevents premature belt wear and system failure, ensuring customer satisfaction and vehicle reliability.

How Modern Car Sensors Optimize Performance and Emissions

Learn how Standard ensures accuracy, speed, and durability in their sensors to maximize engine performance and efficiency.

Do EVs Require Special Brake Pads?

Proper brake pad selection is crucial for EVs to ensure consistent stopping power and long pad life.

Five Tips for your Next Wheel Bearing Job

These practical tips are designed to save you time and frustration, ensuring a smooth, noise-free outcome for your customers.