What does the ignition do?ignition-coil

The purpose of your car’s ignition is to get the engine running by igniting the fuel when the keys are turned. The ignition system needs electricity from the car’s battery to send to the spark plugs, which ignites the air/fuel mixture in your engine to allow you to drive the vehicle. Below are some of the most important ignition components and what they do:

  • Battery – Your car’s battery is the source of electrical power when your car is stationary. Upon turning the keys, the battery sends energy to the rest of the ignition system. The car battery is charged by your car engines alternator.
  • Ignition switch – The ignition switch controls the flow of energy between the battery and the rest of the ignition system. When the light are on the dash (engine not running) the ignition is waiting for the engine to be cranked over.
  • Ignition coil – The ignition coil transforms the battery’s low voltage (12 volts) to the thousands of volts needed to create a spark that will jump across the spark plug gap in each cylinder of the engine.
  • Spark plugs – With the help of energy from the car battery, and the correct timing of ignition coil switching from the engine computer (ECU) the spark plugs produce a spark inside each of the engine cylinders, which ignites the air / fuel mixture and allows the engine to start.

Problems with any of these components can lead to a faulty ignition system, which can cause you to have trouble starting your car. It is important that you or your local mechanics are able to quickly and correctly identify which part of your ignition is failing so that it can be fixed.

Learn more about how the ignition works


Symptoms of a bad car battery:

  • Slow engine crank – When trying to start your car, the engine cranks over slowly and struggles to start.
  • Swollen / bloated battery case – The battery itself may appear to have expanded from its original size. This can be a result of old age and wear.
  • Car battery indicator glass red – if your battery has a small glass or see through round window on top of it, then the colour of the light inside the small round battery window shows the state of charge of your car battery. For example if the car battery indicator glass shows red, it means the battery is flat or discharged and needs to be charged up. If the car battery indicator glass shows green, it means the battery charged and should be working fine.
  • Car battery always going flat – Your car may need to be jump-started often due to a battery not holding its charge. This can also be caused by problems with the alternator.

Car battery replacement service in Hamilton

Symptoms of a damaged ignition switch:

  • Car stalling when driving – If the ignition switch is failing, it may intermittently cut off power to the ignition system while driving. This can lead to unexpected stalling.
  • Car stalling upon startup – Your engine may start momentarily while cranking, before stalling when you release from the crank position.  This can be caused by a bad ignition switch.
  • No power to accessories – If the stereo, lights or other electrical accessories do not turn on, the ignition switch could be the cause of your problem.


Symptoms of a bad ignition coil:

  • Car not starting – If the ignition coil cannot convert the battery’s electricity into a sufficiently high voltage to jump the spark plug gap correctly the engine will not start.
  • Misfiring and stalling – A faulty ignition coil can lead to your engine’s air/fuel mixture not igniting completely. This causes fuel to burn incorrectly, resulting in performance issues such as misfires and stalling.
  • Check engine light – A faulty ignition coil can also trigger the check engine light on your dashboard. This is caused when your engine detects incorrect burning of fuel and engine misfires.

Ignition coil replacement in Hamilton


Symptoms of bad spark plugs:

  • Reduced engine performance – Bad spark plugs can lead to your engine not performing correctly. This happens because the spark plugs are unable to continuously ignite the air/fuel mixture properly. You may notice poor engine performance, reduced fuel economy, rough idling and misfires.
  • Car not starting – In severe cases, the spark plug may become so worn or fouled with carbon that the spark is unable to jump the spark plug gap. In this case on simple older engines you might be able to replace the spark plugs yourself or for many modern engines you will need to get them replaced by a an automotive repair professional, such as your local auto repair shop.

    Please note, if the spark plugs have been significantly worn so that the spark plug electrode gap gets too large, then this can put a lot of strain on the ignition coil(s) secondary winding’s, which can cause them to fail with an expensive repair. This is a good reason to use the correct spark plugs, with the correct spark plug gap and replace them  BEFORE the electrode gap gets too wide!

New spark plugs in Hamilton



Car Ignition Repairs in Hamilton

Are you having problems with your car’s ignition system? If so, we can help! At Grimmer Motors, our team of experienced mechanics can easily diagnose problems with your car’s ignition system. From there, we can provide high-quality repairs that you can rely on.

For car ignition repairs in Hamilton, contact Grimmer Motors today!


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