What Is the Corona Effect?
When a spark plug is operating, high-voltage current travels from the center electrode to the ground electrode. In this process, electrons tend to accumulate near the metal hex section of the plug. Under the influence of high voltage from the ignition coil, these electrons attract nearby charged particles, oil mist, and dust. Over time, this forms a brown to yellow ring around the ceramic portion near the metal hex.
This is what we call the corona effect-a natural occurrence during spark plug operation.
Thanks to BANQIU SPARK PLUG's proprietary ceramic insulation technology and precise manufacturing, our spark plugs maintain excellent insulation even under extreme voltage. Corona is a visual effect, but it does not affect ignition performance or indicate any leakage.
Corona ≠ Leakage
And Definitely Not a Sealing Failure!
The corona effect is often misunderstood. It's not caused by gas escaping from the combustion chamber, nor is it a sign of faulty sealing between the plug and the cylinder head. If the spark plug is properly installed and torqued, there's no need to panic over minor discoloration.
However, if you observe the following symptoms, further inspection is necessary:
1.Heavy, widespread staining on the ceramic
2.Oil contamination on the threads or ceramic
3.Swollen or corroded ignition coil boots
4.Engine misfire or rough idling
What Causes Severe Corona?
Severe corona stains are often caused by aging valve cover gaskets, which allow engine oil to seep into the spark plug tube. This oil, combined with high voltage, can result in heavy staining and eventually corrode the ignition coil-leading to misfires or ignition failure.
BANQIU SPARK PLUG Professional Advice:
Check regularly: Inspect valve cover gaskets periodically for signs of wear, cracks, or oil leakage.
Replace if needed: If oil seepage is found, replace the gasket immediately and clean the spark plug wells thoroughly.
Use high-quality spark plugs: Choose spark plugs like BANQIU SPARK PLUG, designed for high insulation performance and contamination resistance.
Free Sample Comparison: We offer free samples for testing and comparison with NGK, BOSCH, and other well-known brands. Experience our performance in real-world conditions-see the difference for yourself.
In Summary:
If you see light brown or yellowish stains near the ceramic base of your spark plug, especially around the metal hex area, it is most likely a normal corona effect. There's no need for excessive concern.
However, if the stains are unusually severe or accompanied by oil deposits, it's time to inspect your engine's sealing system and resolve any underlying issues.
Choosing BANQIU SPARK PLUG means choosing safety, reliability, and professional performance.
Let us be your trusted ignition system partner-powered by precision, proven by results.
