If your engine misfires, lacks power, or idles rough, your spark plugs might be trying to tell you something. In this video, we break down everything you need to know about spark plugs — how they work, what they look like when they fail, and how to choose the right one for your car.

Whether you’re a DIYer, technician, or someone trying to understand a repair quote, you’ll learn:

The anatomy of a spark plug and how it creates combustion

The critical role of heat range and why the wrong one can cause serious engine damage

How to identify common spark plug failures (carbon fouling, overheating, oil contamination, cracked insulators)

What misfires feel like and what your check engine light is really saying

When to replace your spark plugs (and how long they actually last)

Tips for proper installation, gapping, and torque

Why reading a used spark plug can be the best free diagnostic tool in your shop

We also cover how spark plug issues tie into fuel economy, engine performance, and long-term reliability. If you’ve ever wondered what that little part at the end of your ignition system really does — this is the video for you.

📷 Real-world examples