Why Your Car Engine Light Flashes On and Off

2 mins read

All warning lights go off when you start your vehicle except when you fail to do something you are expected to do, like fastening the seat belt or closing the door.

However, the check engine light of your car can come on while driving and then stop after a few flashes. When this occurs, it shows something is wrong with your vehicle, and it may require a car service North Sydney.

Check engine lights are connected to the engine control unit (ECU) that controls fuel supply and injection, ignition, fuel-to-air ratio, and the timing of valve closing and opening to ensure optimal engine performance. When the data from ECU differs from the stored standard value, the check engine light will reflect it by turning it on.

Engine misfire

Engine misfire is often the cause of engine flash light while driving. Engine misfires occur when one or more cylinders to power your vehicle fail to produce power.

An engine misfire is a serious issue for your vehicle and can cause severe damage to your car engine if not urgently managed.


Causes of an engine misfire

The most common cause of engine misfires are

  • Faulty spark plugs
  • Old coil packs
  • Low compressor
  • Faulty ignition coil
  • Intake manifold gasket leak
  • Low fuel pressure
  • Faulty fuel injector
  • Bad engine sensor

Signs of an engine misfire

  • Unusual sound
  • Gas smell
  • Illuminating check engine light
  • Bumpy driving experience
  • Sluggish acceleration
  • Black exhaust
  • Check engine light
  • Vibration

Engine light illumination

Check engine light is a warning sign that your car or some part of it has a problem, and the more you drive it in that state, the more damage you are causing to your car engine.

The check engine light shows the presence of an error but not the error itself. However, the severity of the underlying issues can be known through the behavior of the light.

There are three typical behavior of check engine lights;

●       Flashing

Flashing is the continuous on-and-off state of the light. The light neither stays on nor off. Flashing means your car has a problem but not something serious. Such repairs are easy and not time-consuming.


●       Intermittent illumination

Here, the check engine light is on for a while, then goes off for a similar period and comes on, then goes off. This is a soft failure which is also associated with specific errors.

●       Continuous Flashing

Continuous flashing indicates an emergency that the car has to be parked and towed to a mechanic shop for assessment and repair.

Other Possible Reasons for Check Light Flashing Then Stopping While Driving

Many other things could cause the check light to blink while you drive. The following are the probable cause;

  • Faulty Oxygen Sensor
  • Unfit gas cap either too big or too loose
  • Bad catalytic converter
  • Faulty mass air flow sensor
  • Damaged air filter valve
  • Faulty exhaust gas recirculation system

Whatever the cause of the engine check light flashing, You should treat it as urgent because if you don’t, the car condition can worsen.

Take your car to car north service Sydney and have them run a diagnostic test on your car to know what is wrong.