4 Signs Your BMW Ignition Coil is Failing

Across various automobile brands, BMW has gained respect among drivers for its high functionality, smooth performance, and elegant design. However, whether or not you enjoy this continuous top-level performance depends on your vehicle’s condition.

Before you can drive your BMW, you need to start the engine, which is where the ignition coil comes into play. This coil plays a vital role in your vehicle ignition and must always be in proper condition. When the ignition coil becomes faulty, your BMW’s engine may begin to experience performance-related issues or not start at all.

The Function of an Ignition Coil

The ignition coil acts as a compact electrical transformer that generates the high voltage required to produce the ignition spark that ignites the fuel/air mixture and starts the engine. Within the ignition coil, you have two coils: a thick copper wire that forms the primary winding coil, and a thin but long copper wire that forms the secondary winding coil. Both coils wrap around a laminated iron core.

When the ignition switch is turned, a high voltage of around 15,000 to approx. 30,000 volts is generated from an existing 12-volt in the ignition coil. This voltage is then distributed to the spark plugs for the ignition of the fuel/air mixture. The coil wires block voltage from moving from the secondary winding to the primary winding to prevent a short circuit.

Symptoms of a Failing Ignition Coil

Although the ignition coil was designed to last well over 100,000 miles, some factors could accelerate the failure of the coil, which include overheating, internal short circuits, faulty wiring, or mechanical damage from engine vibration. Irrespective of these causes, several signs can indicate the presence of a failing ignition coil. Some of these signs or symptoms include:

• Poor Fuel economy: A failing ignition coil affects its ability to provide high-voltage ignition spark, causing one or several cylinders to miss the combustion process intermittently or completely. This results in fuel waste and reduced engine performance. Consequently, you have to spend more money on gas. However, there is a high possibility that your reduced fuel efficiency could have resulted from other factors, including a defective spark plug, oxygen sensor, or air filter.
• Stalling: Your BMW stalling is a common sign of a failing ignition coil. This faulty ignition coil sends irregular sparks to the spark plugs, which may cause your car to come to a complete stop. Besides bringing your vehicle to a halt, stalling also causes difficulty when restarting the car.
• Engine misfiring: Another sign of a failing ignition coil is an engine misfire. When the coil fails to provide the adequate voltage required for ignition spark, it causes your engine to misfire. You may notice a coughing or sputtering noise or experience jerking and spitting when speeding.
• Illuminated check engine light: A faulty ignition coil affects your engine combustion, which in turn impacts your vehicle performance. Consequently, the improper combustion process and reduced engine performance trigger the check engine light to notify the driver of the developments. If you notice any of the following symptoms, you should attend to it immediately before it causes significant engine damage to your BMW.

Causes of Ignition Coil Failure

While the ignition coil was designed to last for long, it could fail because of the following factors:

• Overheating: The ignition coil does not perform well under extreme temperatures. Overheating impacts the ability of the coil to conduct electricity and could cause it to fail sooner than expected.
• Vibrations: The coil’s windings and insulation could become damaged from excess vibrations, resulting in shorts in the secondary windings.
• Wear and tear: The ignition coil wears down after an extended period of use. An old ignition coil may cause the insulation coils between the primary and secondary windings to degrade, resulting in frequent overheating of the coil, causing total breakdown.

Andre’s Auto Services for Your BMW Maintenance and Repairs

If your BMW is experiencing ignition coil failure, the best thing you can do is bring it to our experts at Andre’s Auto Services. We have offered nothing less than affordable and high-quality services to the drivers in Chicago, IL, for the past 25 years.

We are highly skilled in the repairs and service of European vehicles, including Audi, BMW, Mercedes Benz, Land Rover, Volvo and Volkswagen. Please call or visit our shop for your next service appointment!