In an ideal world, a flashing check engine light caused by a misfire would always be resolved by replacing the ignition coil. But unfortunately, a misfire can be more than just a lost spark from an ignition coil.
The most typical symptoms of a faulty ignition coil in an Audi include engine hesitation or lack of power when accelerating, rough idle, misfires, excessive fuel consumption, the check engine light activates, and even trouble starting. If the ignition coils are severely damaged, the engine will not start in the worst-case scenario.
Before delving deeper into any potential ignition coil issues, it’s a good idea to understand what an ignition coil is and how it operates.
What is Ignition Coil?
The ignition coils in the Audi are part of the ignition system responsible for amplifying the relatively modest battery voltage of 12V to tens of thousands of volts for the spark plugs.
Driving your Audi with faulty ignition coils might cause engine or catalytic converter damage, so you must act quickly to avoid more costly repairs.
What causes the ignition failure in Audi?
Under typical operating conditions, ignition coils are prone to wear and strain and will eventually break, usually around 100,000 miles. Ignition coils in an Audi can fail prematurely due to a variety of factors such as overheating, moisture intrusion, engine oil leak, or issues with other ignition system components such as bad spark plugs, which can cause a coil to output higher voltage than usual, significantly reducing its working life.
2. Oil leakage in the spark plug wells
Oil leakage in the spark plug tube can impede the proper operation of the ignition coil in the Audi, causing the engine to misfire and potentially causing the coil to be damaged. This is typically caused due to a leak in the spark plug tube seal in the valve cover. Replacing these seals largely resolves the leak.
2. Blowing of the fuse
The ignition coils in the Audi require electricity to function. In the case of a blown fuse, the circuit is disrupted, and the coils do not fire. Replacing the blown fuse with a new one with the specified amp rating can sort the issue at once.
3. Damage by rats or other rodents
If bite marks are detected under the hood, it is quite likely that a rodent has let off steam in your Audi’s engine compartment. Then, thoroughly inspect all cables and hoses for damage, including electrical wiring and ignition coil connectors.
If you have problems with the ignition coils, it may influence the entire vehicle’s performance. This is why it’s critical to be on the lookout for the signs of a defective ignition coil, which we’ll go over in more detail ahead in the article.
What are the Signs and Symptoms of a faulty ignition coil in Audi?
1. Troubles in starting the engine
Difficulty in starting your car’s engine may signal an issue with your ignition coil. As previously stated, most modern engines have numerous ignition coils. Therefore, you may have a faulty ignition and difficulties starting your engine if you have many bad ignition coils. However, various issues might result in difficulty in starting an engine, so problems starting the engine alone isn’t enough cause to rule out an ignition coil problem.
2. Misfiring or stalling of the engine
If your engine misfires or stalls during idle or when you suddenly stop or accelerate, you may have an issue with your ignition coil. A misfire, which can be heard as a coughing or spitting sound or felt like a jerk or severe vibration, indicates that one of the engine’s cylinders is not firing properly.
Misfires are more prone to occur when the engine is stressed, and they can produce pollutants. As a result, increased emissions and the odor of gas coming from the exhaust are signs of a faulty ignition coil.
3. Bad fuel economy
Excessive fuel consumption is a common symptom of faulty ignition coils or spark plugs. So if your car is getting much less gas mileage than usual, it’s time to check the ignition coils and spark plugs.
4. Illumination of the check engine light
The check engine light is intended to alert you that anything is amiss with the engine. For example, your check engine light will illuminate if you have an ignition coil problem while driving. Of course, the check engine light should never be ignored, but like the other signs we’ve mentioned earlier, it can be caused by a multitude of problems.
The OBD-II (on-board diagnostics) check is one of the simplest techniques to determine why an engine light is illuminated. A mechanic can perform an OBD-II check for you, or you can perform your own using an OBD-II scanner.
There are many other ways to test an ignition coil; read ahead to know.
What are the tests to diagnose the cause of a faulty ignition coil?
If an ignition coil is tested incorrectly, it can be dangerous. If you are unsure how to test an ignition coil safely, seek the assistance of a skilled specialist.
You can test for ignition coil problems by performing an OBD-II check, which will necessitate the use of an OBD-II scanner. Codes indicate engine misfires from P0300 to P0312, while ignition coil faults are indicated by codes P0350 to P0362.
You’ll have to take a look at most other types of ignition coil tests. The placement of the ignition coil varies from vehicle to vehicle, so consult your owner’s handbook or a search engine to see where your car’s ignition coil is located.
Once you’ve located the ignition coil, search for any obvious signs of damage. Inspecting the ignition coil wiring is one of the simplest steps. If the wires are damaged or corroded, this may be the root of your ignition coil difficulties.
Next, examine the coil harness and connector for flaws, particularly bent terminal pins and loose connections. If you still can’t identify a problem, remove each ignition coil from the engine and scrutinize them for evidence of damage.
Depending on the type of ignition coil and your level of skill, you can do additional tests on it.
Can the ignition coil be repaired?
A damaged ignition coil cannot be repaired; it must be replaced. However, if the ignition coil has been polluted by an oil leak in the spark plug tube/well and the end of the ignition coil boot has not become squidgy, there are chances to restore its functionality by cleaning it with an electronic cleaner or MAF sensor cleaner. Nonetheless, if you see corrosion or rust on any of your Audi’s ignition coils, they must be changed.
Suppose you observe a considerable loss of performance or engine reluctance with excessive fuel usage in your Audi. In that case, you should immediately inspect the ignition system, which includes the spark plugs, ignition coils, and their connectors/wires.
Anyway, it is always recommended that a layman must attend a workshop. However, a competent mechanic will be able to diagnose the problem for you quickly.
The good news is that a faulty ignition coil is not a life-threatening emergency, and it is also not prohibitively expensive to repair. You can even drive with a defective ignition coil if necessary, albeit the car will run poorly. But, if left unchecked, an ignition coil problem can hinder other parts of the car, particularly the catalytic converter.
DAScenter offers Audi repair and has a team of trained and experienced professionals who will take care of your luxury car.