Every vehicle has an ignition coil consisting of a primary and secondary coil. When you start the engine, the primary coil draws power from the battery setting up a magnetic field that sends power to the secondary coil. That secondary coil carries a voltage high enough to activate the spark plug and the resulting spark lights the mixture of air and fuel. Any malfunction will cause easily recognizable ignition coil symptoms. Here are some things to look for if you think you need to replace the ignition coil.
1. The Car Keeps Stalling
One symptom of a bad ignition coil is the car will stall until the coil fails completely and the car will not start at all. If the ignition coil fails to feed a steady current to the spark plugs, the pistons will not fire evenly. The engine is prone to stalling anytime it senses the air and fuel mixture is not right.
2. The Engine Misfires
If the spark plugs are not firing properly, the engine runs rough because the pistons cannot fire at regular intervals, as they should. The engine may sputter and sound like it is going to shut off. Vehicle owners may notice jerking at high speeds and a vibration anytime the vehicle idles. This symptom is difficult to ignore because the vehicle will run rough and the ride will be uncomfortable.
3. The Engine Struggles to Start
Difficulty starting the engine is usually the first sign that something is wrong with the ignition coil. If the ignition coil malfunctions, the spark plugs do not fire properly because they do not get enough of a charge when the operator turns the key.
4. The Engine Backfires
The mixture of air and fuel fails to fully ignite when the spark plugs do not fire as they should. Whatever unburned fuel is left travels through the exhaust system and can cause the engine to backfire. A backfire is a sign the ignition coil is failing and indicates further damage to the engine may already be occurring. You should take the vehicle to a reputable repair shop because the exhaust system is at risk of severe damage if the vehicle continues to backfire.
5. The Car Uses More Fuel than Usual
Since the engine is misfiring and unburned fuel is expelled through the exhaust system, the vehicle’s fuel mileage will decrease. The longer the problem goes unchecked, the more money you will waste on fuel because you will have to fill the tank more often.
What are the Consequences of an Ignition Coil Failure?
The engine will not run when the ignition coil fails because the spark plugs are unable to ignite the fuel and air mixture in the combustion chamber. This can be a real problem because sometimes the vehicle operator has no clue when the engine will fail and it could happen even if the vehicle is in motion and driving down the road. Protect your vehicle with a visit to an experienced mechanic if you notice any of the ignition coil symptoms discussed here.
Martin does work for <a href="http://www.davidstanleychevrolet.com">David Stanley Chevrolet</a>— a dealer of premium used cars Oklahoma City trusts. Martin enjoys writing about auto repair and the latest in automotive innovations.