Ignition Coil Problems: Symptoms and Solutions
NaTasha Brand • June 9, 2025
& Why DIY Isn’t Always the Answer
Your car’s engine is a symphony of moving parts, and the ignition coil is the conductor making sure the spark plugs fire in perfect rhythm. But when this critical component fails, your engine’s performance goes from smooth jazz to a broken kazoo.
At Ric Henry’s Auto Service, we’ve seen our fair share of ignition coil failures—and we know just how frustrating (and confusing) they can be. So, let’s break down what ignition coils do, how to spot a failing one, and why trusting a professional is the smartest move for your ride.
What Does an Ignition Coil Actually Do?
Think of your ignition coil as a high-voltage transformer—it takes your battery’s measly 12 volts and amplifies it to 20,000+ volts, creating the spark that ignites the air-fuel mixture in your engine. Without it, your spark plugs would just sit there, useless, and your engine wouldn’t run at all.
How Do Ignition Coils Work?
- Primary Circuit: Battery voltage flows through the coil’s windings, building a magnetic field.
- Secondary Circuit: When the engine’s computer signals, the magnetic field collapses, sending a high-voltage surge to the spark plug.
- Boom! Spark plug fires, combustion happens, and your engine keeps running smoothly.
Modern engines typically have one coil per cylinder (Coil-On-Plug or COP), while older vehicles may use a single coil with a distributor. Either way, when a coil fails, your engine definitely lets you know.
Symptoms of a Bad Ignition Coil
A failing ignition coil doesn’t always die suddenly—sometimes it gives warning signs before leaving you stranded. Here’s what to watch for:
1. Engine Misfires (The Jerky Ride)
- Feels like your car is hiccuping or stumbling, especially under acceleration.
- Check Engine Light may flash (a serious misfire can damage the catalytic converter).
2. Rough Idling (Shaking Like a Nervous Chihuahua)
- Vibrations at stoplights, uneven RPMs, or even stalling.
3. Hard Starts & Poor Performance
- Takes longer to crank, struggles in cold weather, or lacks power when accelerating.
4. Terrible Gas Mileage
- Weak spark = incomplete combustion = wasted fuel.
5. Backfiring or Strange Exhaust Noises
- Unburned fuel igniting in the exhaust? Yep, that’s a bad coil symptom.
Why You Should Let Professionals Handle Ignition Coil Repairs
Sure, you could buy a cheap coil online and try replacing it yourself. But here’s why Ric Henry’s Auto Service is the smarter choice:
✅ Accurate Diagnosis– A misfire could be a bad coil… or a faulty spark plug, wiring issue, or even a fuel problem. We pinpoint the real culprit.
✅ Dealer-Level Tools & Equipment– We use the same advanced diagnostic scanners and OEM-grade tools as dealerships.
✅ Nationwide Warranty – Our repairs come with a 3-year/36,000-mile warranty—something no YouTube tutorial can offer.
✅ Full-Service Auto Care – While we’re under the hood, we can check related systems (plugs, wires, fuel injectors) to prevent future issues.
Trust Ric Henry’s Auto Service in San Angelo, TX
Ignition coils may be small, but they’re critical! Guessing wrong can lead to bigger (and pricier) problems. At Ric Henry’s Auto Service, we don’t just swap parts and hope for the best. We diagnose, repair, and make sure your engine runs like it should.
So, if your car’s acting like it’s got a case of the Mondays, bring it to us. We’ll get you back on the road - without the sparky drama.
Is your car shaking when you brake? Discover the causes of brake vibration and why San Angelo trusts Ric Henry's Auto Service for expert repair. Family roots since 1966.
Is a new car worth the cost? Discover the financial reality of car ownership including depreciation, insurance hikes, and why maintenance beats replacement. Learn how Ric Henry's Auto Service in San Angelo provides trusted, honest repair services to save you money.
Learn the history, symptoms, and importance of ball joints. Discover why professional replacement matters and why Ric Henry's Auto Service is San Angelo's trusted dealership alternative with a 3-year warranty.
Discover the fascinating history of cruise control from inventor Ralph Teetor to modern adaptive systems. Learn why you need a tech-forward shop like Ric Henry's Auto Service in San Angelo, Texas, for honest diagnostics and dealer-level care. Serving generations since 1966.
Having power steering problems in San Angelo? Ric Henry's Auto Service explains what power steering does, symptoms of failure, maintenance tips, and the difference between hydraulic and electronic systems. Dealer-level care since 1966.
Electric parking brakes need professional calibration. Learn how they work, symptoms of failure, and why Ric Henry's Auto Service in San Angelo is your trusted expert. Dealer-level care since 1966.
Is your luxury SUV sagging or riding rough? Learn the symptoms of air suspension failure and why Ric Henry's Auto Service in San Angelo is your trusted dealership alternative with generations of expertise.
Does idling your car in a West Texas summer waste gas and cause engine wear? The answer might surprise you. Ric Henry's Auto Service in San Angelo explains why the warm-up ritual is outdated and shares tips to save fuel and protect your engine in the July heat. Serving Texas drivers since 1966.
Sweet smell coming from your car in San Angelo? That is a coolant leak! Learn the causes, symptoms, and why you need professional repair from Ric Henry's Auto Service. We have been trusted since 1966. Get dealer-level care with a 3-year, 36,000-mile warranty. Call us today!
Keep blowing fuses in your San Angelo car? Learn what causes blown fuses, symptoms to watch for, and why Ric Henry's Auto Service, San Angelo's trusted dealer alternative since 1966, should handle your electrical repairs. 3-year/36,000-mile warranty. Honest diagnostics. Book online today.
