How to Detect an Ignition Coil Failure in a BMW?

An ignition coil’s function is to convert the low current from a vehicle battery into sufficient power to ignite the gasoline and start the engine.

When an ignition coil fails, it may lead to a variety of mechanical and performance concerns such as loss of power, checking the engine light on, hard starts and stalling, jerking, vibrating, etc…

In this article, we’ll go over the proper functioning of an ignition coil, what does it, what causes the ignition coil to fail, its common symptoms, and some of the best BMW ignition coils on the market.

So, let’s get started.

What is the ignition coil? 

The ignition coil is a silver tube with a black plastic aperture that connects to your engine.

The ignition coil is a transformer at its core. Its function is to transform low voltages into high voltages.

The high voltage output powers spark plugs, which release this energy in the form of a spark, which ignites the compressed air and fuel combination within the engine.

These sparks both start and keep the combustion cycle going, enabling you to operate your BMW.

To keep it simple, if the ignition coil breaks, your BMW’s engine will not start.

What causes the ignition coil to fail?

Some common reasons that cause an ignition coil to fail are:

a) Damaged or worn spark plugs

When spark plugs wear out, the ignition coils are forced to run at considerably greater power.

Keeping your spark plugs in good condition helps lessen the likelihood of an ignition coil failure.

As spark plugs wear out, the space between each spark plug is enlarged, requiring the coil to give a larger voltage to bridge the gap.

This added pressure on the ignition coil may result in voltage overload, overheating, and ultimate failure.

b) Vibrations 

Vibrations may cause shorts or breakage in the secondary windings by damaging the ignition coil windings and insulation.

The capacity of ignition coils to carry energy may also be hampered by overheating.

c) Deterioration 

Wear and tear are frequent causes of ignition coil failure. It deteriorates the insulation between the primary and secondary coil windings, as well as the primary coil. 

The loss of insulation may cause the coil to overheat.

d) Voltage supply error 

Overload or excessive wear on the ignition control unit is the most common cause of this sort of failure.

It may also be caused by defective wiring or a weak battery.

e) Mechanical Impairment 

Mechanical failures include valve cover gasket failure, broken insulation, and leaking engine oil.

These may cause damage to your ignition coil.

f) Contact Faults 

Debris accumulation, engine cleaning, and high humidity or moisture buildup beneath the hood are the most common causes of contact problems.

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Common Ignition Coil Failure Symptoms in BMW 

Recognizing ignition coil failure symptoms will help you solve the problem before it becomes too grievous. 

Below are some of the most common symptoms of a faulty ignition coil in BMW:

1. Power loss 

One of the earliest signs of ignition coil failure is this. If you have ignition coil problems, your car may feel sluggish and will lose power.

This is created by erratic sparks that ignite the necessary combustion.

If your car loses power, take it in for maintenance to prevent additional damage that will cost you more money to restore.

2. Engine light turned on 

If your car misfires or is difficult to start, the “check engine” light will illuminate.

This issue is often caused by a faulty ignition coil.

3. Cheap fuel economy 

It’s a symptom of ignition coil failure if you travel the same distances but stop at the gas station more often. 

When an ignition coil fails, an inaccurate 02 sensor reading delivers more gas to the engine than necessary.

You’ll need to fill up more often because the spark plugs aren’t receiving enough power, and the system compensates by injecting extra gasoline.

4. Backfiring 

A faulty ignition coil might be the source of your vehicle’s backfiring. 

When unused fuel in the combustion cylinders bursts, generating black smoke to emanate from the exhaust pipe and a strong odor of gas, the car emits a loud boom sound.

If the issue is not addressed promptly, it will cause system harm. 

5. Improper engine starting 

When you speed, a faulty ignition coil will cause your car to misfire.

A misfire might cause your car to shut down while you’re driving in severe situations. The misfire occurs when one of the cylinders ignites erroneously or does not fire at all.

The exhaust has the potential to harm the catalytic converter and other engine components. 

6. Stalling and trouble starting 

For an engine to start and a vehicle to operate, the ignition must spark precisely at the appropriate moment. 

It will be difficult to start the engine if an ignition coil fails to give the needed voltage to the spark plugs.

If your car stalls when you come to a halt or even shuts down entirely, it might be due to a faulty ignition coil delivering erratic sparks to the spark plugs.

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How to Pick the Best BMW Coil Pack When Buying New? 

It is no debate by now that the ignition coil is a very important part of a car. To put it simply, your car won’t even run properly if the coil is not working properly.

The way to fix the problem is by replacing a faulty ignition coil.

And if you’re going to buy a new coil pack, it has to be an utmost priority to make sure that you buy the best pack at your disposal.

Here are two important factors to keep in mind when buying a new coil pack: 

a) Quality 

Initially, coils were formed from materials such as paper, varnish, asphalt, or oil (for insulation).

Nowadays, Epoxy is being used by manufacturers.

This avoids any potential difficulties caused by gaps in the windings.

They also use a diode to prevent a reverse pulse from forming. 

Upgrade to more contemporary materials unless you’re rebuilding a historic automobile and want to maintain everything original.

If you’re replacing a coil in an older car or a coil in a newer vehicle, look for the greatest quality ignition coil constructed of the best materials.

Also, go for the best brands. Don’t pick something local or cheap.

b) Compatibility 

The coil you choose must be the proper one for your car.  

If it doesn’t, it generally won’t fit, and if it does, installing it might harm your engine.

Many automotive websites will instantly alert you of an inaccurate fit if you supply the model, make, and year of your vehicle.

This will help you ensure that the ignition coil you purchase is the right one for your car.

What are the Best BMW Ignition Coils to Choose for High-Performance?

The ignition coil is responsible for providing the spark that ignites the air-fuel mixture in the engine’s cylinders. If this component fails, the engine will not start.

In some cases, it may be possible to drive with a failed ignition coil, but doing so can damage other components in the engine and may eventually lead to a complete engine failure.

It is best to have the ignition coil replaced by a qualified mechanic as soon as possible.

Here are the 3 best BMW High-performance ignition coils you can consider when buying new: 

1. Bosch 0221504470 OEM Ignition Coil 

Assist in the performance of your BMW.

Aside from mechanical equipment, Bosch is proud of its automobile components. 

An increment in several mechanical features should be sufficient to meet your requirements. And as far as the pricing goes, it is a decently priced option.

Features and Benefits:

Relying Voltage – Among every other well-known brand, Bosch has already proven itself in terms of performance. 

Continual voltage transition generates additional spark energy, which results in a smooth, quick, and secure ignition. 

Consistent Connection – Every joint leaves the factory with extra care. The connection nevertheless stays vulnerable to metal corrosion or rust. 

However, the exquisite features provide a high level of protection against rigors.

Broad Applicability – The finest BMW coil pack is suitable for a variety of BMW models from 2006 to 2018. Its design is compatible with BMW 1, 2, 3, 4, 5, 6, 7 Series, as well as M5 and M6 vehicles.

Pros 

• Durable service life. 
• All electrical connections are intact. 
• Insulation of the highest quality. 
• OEM satisfaction is standard.

Cons 

• Awful plug fitting.

2. ENA Pack of 6 Ignition Coils

Very few companies can claim to have high-quality accessories for ignition and ENA is one of them.

The unique design for winding results in the greatest quality despite its small size and weight.

Furthermore, the price establishes a strong ratio to the performance it offers.

Features and Benefits:

The output of Energy – The intact system continues to provide the required combustion power.

Getting the coil installed results in an instant resolution to engine problems.

Easy Setup – ENA creates coils for the direct substitution of factory-made accessories. 

Every component is designed to surpass OEM specifications.

Its physical design allows for a quick, easy, and appropriate installation. You can rest assured of its dependability.

Pros 

• Effortless operational design. 
• Transmission shifts are constant. 
• Installation of the system directly. 
• Fuel usage is appropriate. 

Cons 

• Flexible metal clips. 

3. Delphi GN10328 Ignition Coils

Delphi is still in business with gears like this one.

Before servicing, testing of OE-level is combined with sophisticated diagnostics. The pricing seems to be a little higher but within the acceptable range.

Features and Benefits:

Proven Material – Intelligent manufacturing is employed to apply innovative design. Every component is made of tested materials to ensure maximum efficiency.

OE Criteria – The newest OEM technology is all set to surpass the critical criteria. Advanced diagnostics also include reset adaptation, EGR valve coding, and throttle actuator customization.

Protective Measures – The ignition coil from Delphi BMW devoted a significant amount of time to researching the ignition mechanism.

Vibration, temperature variation, and damaged components all contribute to decreased efficiency.

Pros 

• Excellent voltage differences. 
• The function of adjacent winding. 
• Maintain the insulation from the inside. 
• Design with pressurized vents.

Cons 

• A few minor fit concerns

Final Thoughts

If your BMW car’s ignition coil is faulty, the best thing to do is to take it to a qualified mechanic and have it replaced.

Depending on the severity of the damage, you may be able to drive with a faulty ignition coil for a short period of time, but doing so can damage other components in your engine.

So, get the ignition coil replaced as soon as possible.