Audi A4 Ignition Coil Failure Symptoms (9 Things To Be Aware Of)

Most cars have internal combustion engines that run on fuel, air, and electricity. The ignition coil is essential in providing the electrical component to that equation in modern vehicles.

As a result, if your ignition coil fails, your Audi A4 engine will not start. Worse, it may completely stop. So, let’s find out more about its symptoms here!

Audi A4 Ignition Coil Failure Symptoms

The most common signs of faulty ignition coils in Audi A4 are check engine light display, decreased gas mileage, misfiring and backfiring, difficulty engine starting, engine stalling, and sometimes hard starting, and poor acceleration will also happen. In a worst-case scenario, if the ignition coils are in terrible condition, the engine will not start.

Discover more about Audi A4 ignition coil failure symptoms. Here are nine things to be aware of. Continue reading!

1. The Display Of Engine Light

Because a terrible ignition coil significantly influences engine functionality, the check engine light will display on Audi A4’s dashboard. There are even vehicles that only have one ignition coil and spark plug.

Without at least one able-to-work ignition coil, your engine will crank even if no sparks are formed inside the cylinders.

In addition, your vehicle’s check engine light can indicate various problems with your car.

However, the ignition coil is most likely to blame if you have encountered any of the preceding four symptoms and have a check engine light on.

2. Decreased Gas Mileage

Ignition coils may completely fail or fail inconsistently. It implies you may have a coil that deteriorates over time.

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As a result, even if your Audi A4 appears to be functioning correctly, you should keep an eye out for decreased gas mileage.

Even if it is not due to a faulty ignition coil, reduced gas mileage is an indication that there is something wrong.

3. Backfires And Visible Smoke

Modern engines are not supposed to backfire. These loud sounds in your Audi A4 occur once unburned fuel unexpectedly escapes from the exhaust system.

In addition, a malfunctioning ignition coil is one of the most common causes of backfires. Unfortunately, if backfires are not addressed quickly, they can cause severe engine damage.

4. Loss Of Engine Power

Audi A4 with faulty ignition coils frequently runs rough. It means you may start noticing a rough feel or sound when your car is idling.

Therefore, your vehicle’s performance may also suffer. As a result, a faulty ignition coil can cause sluggish acceleration, and your car may stall.

5. Difficulty Engine Starting

Difficulty Engine Starting

Your Audi A4’s engine requires a spark at the perfect time to function. However, a hard start may occur if a spark plug does not receive the proper voltage to generate a spark.

It could indicate that the ignition coil is not functioning correctly. While this issue can occur in any coil configuration, it is more prevalent in engines with a separate ignition coil.

6. Engine Misfires

One of the most typical symptoms of faulty coil packs is misfiring. Anything else you experience is a result of the misfiring. What is starting to cause the misfire is the real question.

The ignition system in your A4 is made up of more than just coil packs. Spark plugs and plug cables are also available.

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Non-ignition-related factors can also cause a misfire. It could include a lack of fuel pressure, faulty fuel injectors, or a jumped timing chain (or belt).

Because there are so many possible causes for a vehicle to misfire, we recommend checking for trouble codes first.

7. Engine Stalling

If your Audi A4 begins to stall while driving, it could be due to a faulty ignition coil. It can happen when you’re already stopped, but it can also occur while moving.

If the coil is only beginning to fail, it will send erratic electrical charges to the spark plug. That is why you may usually be driving and then encounter problems later.

When you’re trying to move, and the stalling begins, you’ll eventually come to a complete stop and won’t be able to restart.

8. Engine Not Starting

A bad ignition coil could also cause a no-start situation for your Audi A4.

In addition, a faulty ignition coil will affect the operation of the entire engine in cars that use a separate ignition coil as the spark generator for all cylinders.

If the coil fails, the engine will be left without a spark, resulting in no spark or start condition.

Further, troubles with ignition coils are typically easy to detect because they produce symptoms that the driver will notice.

However, if you suspect a problem with your vehicle’s ignition coils, have it examined by an expert technician.

9. Accelerating Issues

The fuel and ignition systems react when you press the gas pedal on your A4. Therefore, acceleration should be felt if it has decreased.

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Also, the fewer cylinders your engine has, the greater the impact one cylinder cannot fire correctly will have on engine efficiency.

So, when you have one or more malfunctioning coil packs, the A4’s acceleration will be weaker, and you will probably have a jerking sensation.


Be conscious that most of the signs of a bad coil pack in your Audi A4 may be caused by other problems with the ignition system.

But knowing all these symptoms can help you quickly determine the problem with your vehicle and prevent further damage.

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