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If your BMW is suffering from a failing ignition coil, we can certainly help. The ignition coil is a sensitive and vital part of your Bimmer that helps your car start. Usually, these components can last from 80,000 to 100,000 miles. However, driving conditions, your driving habits, and your maintenance schedule can all affect the longevity of the ignition coil. In this article, we’ll discuss how to recognize an ignition coil problem and your next steps.
What is an Ignition Coil in a Car?
Another name for the ignition coil is a spark coil. It is an essential part of your car’s ignition system. It first draws electricity from the car’s low-voltage battery, then, with the help of the spark plugs, converts it into a spark, which ignites the fuel. This starts your car!
Why Does an Ignition Coil Fail?
Some root causes that may induce an ignition coil to malfunction could be the following:
- Worn, Gunky Spark Plugs: The ignition coil must work in conjunction with the spark plugs to make your Beemer go. Anything that negatively impacts the spark plugs can have a disastrous effect on the ignition coil.
- Heat and Vibration: Extreme heat and vibration can damage the insulation of the ignition coil.
- Engine Runs Too Rich or Too Lean: When the air-fuel mixture is incorrect, it will certainly spoil the ignition coil.
- Other Reasons: Here’s a list of other factors that may result in a deteriorated ignition coil.
- Internal short circuits
- Faulty wiring
- Problem with the ECU (Engine Control Unit)
- Oil leaks on the ignition coil or spark plugs
- Water damage to the spark plug recesses
- Weak battery
Signs of a Defective Ignition Coil
A bad ignition coil may manifest itself in the following ways. A trained mechanic will be able to inspect and pin-point the actual issue.
- Misfiring Engine: If the ignition coil is unable to generate the spark to ignite the air-fuel mixture within the cylinders, your car will misfire.
- Decreased Fuel Economy: Due to the misfirings a malfunctioning ignition coil causes, engine efficiency goes down, and so does fuel efficiency.
- Car Backfires: This is a type of misfiring where the air-fuel mixture ignites in the exhaust, intake, or crankcase and triggers an explosion. The fire from this forces through the exhaust system and escapes through the tailpipe. You will hear a loud pop and actually see fire from the rear of your car.
- Rough Idling: Due to the incorrect air-to fuel mixture passing through the system, the engine misfires, causing your Beemer to lurch or surge while idling.
- Engine Doesn’t Want to Start: The ignition coil conveys electricity to the spark plugs, which create the ignition for the car to start. A damaged ignition coil will prevent your Bimmer from starting.
- Vehicle is Stalling: The same reason may cause your Bimmer to stall during starting, or in a really bad case, your car may simply stop in the middle of the road.
- Reduced Power: You may notice that your BMW’s engine feels sluggish and your car is slow to accelerate.
- Odd Sounds: When you hear sputtering sounds, it could be a deteriorated ignition coil causing the issue because the cylinders are not firing correctly.
- Noxious Emissions: You will see thick, dark, foul-smelling smoke coming out of the tailpipe of your BMW.
- Check Engine Light (CIL): Whenever there is a problem with the engine, this malfunction indicator lamp (MIL) will get illuminated on your dashboard. It can mean any number of things are wrong. A professional mechanic can attach a scanner to your BMW and read the error codes to find out what’s wrong.
Regular Maintenance
It is imperative that you put your Bimmer on a regular maintenance schedule so that we can catch the problems early and fix them. If there’s only a small amount of carbon residue buildup or corrosion due to moisture, a proper cleaning can restore the coil. However, we need to be able to detect the problem early on to do this. Otherwise, we can, of course, refurbish or replace the ignition coil.
Auto Scandia is Your BMW’s Pro Stop
At Auto Scandia, we are your go-to garage. 
Our factory-trained and certified mechanics are eager to offer you professional, personalized, and top-notch service. Give us a call or book an appointment to visit us. We are in Virginia, located in Sterling, Reston, Great Falls, Chantilly, Oakton, and Herndon.