What kills a coil?

Author: Prof. Pedro Rowe III  |  Last update: Sunday, September 7, 2025

The reasons for ignition coil failure can be summarised under four main headings: internal short circuits, mechanical damage, contact failure and faults in the voltage supply.

What kills an ignition coil?

Air bubbles can create a path for electricity inside of a coil, and lead to premature failure. Coils fail for a variety of reasons including heat, vibration, or issues on the secondary side of the ignition system. Coils are commonly found bolted to the cylinder head, either on top or inside of a cylinder specific well.

What burns out a coil?

Improper match between the electrical source and the coil rating is sometimes a cause for coil burn-out: Voltage Too High. The operating voltage should not be more than 10% higher than the coil voltage rating. Excessive voltage causes excessive coil current which overheats the coil.

What ruins an ignition coil?

Ignition coils tend to fail because of bad spark plugs or plug wires. If your vehicle's fuel-to-oxygen mixture is either rich or lean, therefore, your ignition coils may fail prematurely. Additionally, engine heat and vibrations can cause damage to ignition coils.

How does a coil get damaged?

Vibrations can damage ignition coil windings and insulation causing shorts or breaks in the secondary windings. The overheating of ignition coils can hinder their ability to conduct electricity. Wear and tear is a common reason for ignition coils failing.

Why Do Ignition Coils Fail: 7 Common Reasons Why They Go Bad

What causes a coil to stop working?

The reasons for ignition coil failure can be summarised under four main headings: internal short circuits, mechanical damage, contact failure and faults in the voltage supply.

How long will a coil last?

Your Coil Is Used Up

If you're a heavy vaper, using your e-cig many times a day. You might need to change the coil every couple of days. If you are a regular vaper but not particularly heavy, it could last a week or two. Irregular or casual vapers might find they need only change their coil every four weeks.

What causes an ignition coil to melt?

A bad spark plug ignition cable will have a much higher than normal resistance. This high resistance causes a very high amount of voltage to be generated from your ignition coil's secondary winding. This excessive voltage creates a high amount of heat which consequently melts the coil's wire insulation.

How to tell if a coil is bad?

5 Symptoms of a Faulty Ignition Coil
  1. Misfiring Engine. An engine misfire makes the car feel shuddery and as though it's out of rhythm. ...
  2. Engine Backfires. An engine backfire sounds like a bang or sharp cough, and it happens when unburnt fuel ignites in the exhaust system. ...
  3. Less Fuel Efficiency. ...
  4. Check Engine Light. ...
  5. Hard Starts.

Can you repair an ignition coil?

While coils can be repaired, refurbished and replaced, this must be compared to the cost of providing a new unit.

What burns coils fast?

Over-vaping

This can burn out your coil! If you vape a lot in a short period of time, you can burn the coil out by not leaving it enough time to reabsorb some e-liquid. The coil will also get too hot and start to burn. We would recommend taking about 3-5 puffs before allowing the device to sit for a few minutes.

How to tell if a coil is burnt?

If you notice a gurgling sound, a muted flavour, or a burnt taste from your vape, you'll know it's time to change your vape coil.

Can you reverse a burnt coil?

We don't recommend that you rinse out your coils as once a coil is burnt there is no going back and it's better to replace it with a new one.

What is the number one killer of coil windings?

Heat and vibration can damage the coil's windings and insulation causing shorts or opens in the primary or secondary windings. But the number one killer of ignition coils is voltage overload caused by bad spark plugs or plug wires.

Why does my car keep killing ignition coils?

Extreme temperatures, moisture, and exposure to corrosive substances can all contribute to ignition coil failure.

What is the life expectancy of an ignition coil?

The ignition coils in your car's engine must consistently generate huge 15,000 to 20,000-volt charges of electricity so the spark plugs can keep igniting the engine's fuel. Despite how hard ignition coils work, they have a relatively long expected lifespan of 80,000 to 100,000 miles.

What causes a coil to burn out?

If coil burned out while it was continuously energized:

Ambient temperature is too high for the rating of the coil insulation. Prolonged abnormally high voltages are applied or voltage surges occur due to other heavy equipment on the line.

Will a car run with a bad ignition coil?

This voltage is later sent to spark plugs, creating a spark that ignites the fuel-air mixture in the engine's cylinder. Without the ignition coils, your fuel-air mixture wouldn't ignite. As a result, the engine will never run.

How to tell if a coil needs replacing?

5 signs that your coil needs replacing
  1. Burnt Taste. The first and most prominent way to tell your coil needs changing is by experiencing an unpleasant burning taste in your vape.
  2. Bubbling Noise. In this case, your device is literally telling you to change the coil. ...
  3. Weak Flavour. ...
  4. Little Vapour. ...
  5. Leaking Device.

Does leaving the ignition on burn out the coil?

Yes, it will run down the battery. On older cars with ignition points, the coil can be energized continuously instead of pulsating as in normal operation. This can cause the coil to overheat, melt, and fail.

What sparks the ignition coil?

Ignition coils are essentially transformers that convert the battery's low voltage into the high voltage needed to create a spark. Most car batteries operate at around 12 volts, but to produce a spark strong enough to ignite the fuel-air mixture, much higher voltage is needed—often up to 20,000 volts or more.

What happens when a coil goes bad?

A fully functioning ignition coil generates electrical power for the spark plug so when a coil breaks down, the spark plug can no longer ignite the fuel inside the cylinder. As ignition coils serve this essential function, a faulty coil will rapidly cause the whole engine to lose power.

What does a burnt coil look like?

What does a burnt coil look like? At first glance, a burnt coil may not necessarily look any different to a normal coil. The inside wick, however, will show obvious signs of damage with singed and burnt edges.

How often do ignition coils go out?

How Long Do Ignition Coils Last? Ignition coils generally last 80,000 to 100,000 miles. However, as with most vehicle components, certain conditions like the ones below may cause them to fail sooner.

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