Check engine light flashing when accelerating. Possible causes

Is your car experiencing a check engine light flashing when you accelerate? Don’t worry; this article will explain why this issue comes, how you can manage it, and when.

Your car’s operating systems are prone to computer monitoring of everything happening within the car. There are several sensors in the car to detect any issue with the operating systems and the entire performance.

Therefore, there is a problem if you see a check engine light flashing when you accelerate your car.

The common cause of check engine light flashing when the car’s speed is increased could be engine misfiring, overheating, low oil pressure, ignition or spark plug issues, loose gas cap, oxygen sensor, bad injectors, issues with internal engine, or a faulty engine control unit.

A check engine light warns you there is a problem with your car engine; it could be a minor or a major problem affecting the engine’s normal operation.

There are three ways the check engine light may be illuminating when you accelerate your car, continuous flashing, intermittent illuminating, or continuous illuminating.

The continuous flashing will occur as the check engine lighting flashing without stopping when you increase the speed of your car. If your car has this issue, it is warning you about a serious problem affecting the engine. This problem may need you to turn off the engine immediately.

The common cause of this continuous flashing of the check engine light when you accelerate could be an ignition misfire.

Besides engine misfire, several other causes are resulting in checking engine light flashing as the speed of the engine increases.

Faulty Oxygen Sensor

The oxygen sensor has a special role in your car; without it, your car’s engine will work unhealthy. This type of sensor regulates the amount of oxygen needed and the exhaustion of unburned fuel.

However, a bad oxygen sensor doesn’t mean you won’t drive your car; the only issue is that the catalytic converter will be exposed to gradual damage, and MPGs will be lowered.

When you accelerate your car, the broken oxygen sensor won’t be working properly to withstand the engine’s high-speed changes, affecting some of the engine parts, and a check engine light will flash.

Bad spark plugs

Spark plugs are important in your car as they provide continuous sparks to keep the engine running. Therefore, if the spark plug develops a fault like worn-out or failing, it won’t provide enough sparks.

For instance, when you accelerate the car, the engine will need more sparks to burn fuel in the combustion chamber. If the spark plug is broken, there will be combustion effect delays, and therefore, there will be misfiring of the motor and knocking off the engine. In this case, you will see a check engine light flashing on the dashboard.

Engine Overheating

Engine overheating is a serious problem that you should not ignore. There are several reasons why the engine will overheat, for instance, if the cooling systems along the engine operating systems have failed.

Such coolants include oil, air, water, and other fluids. Lack of or poor cooling systems in the engine will result in overheating due to friction of some engine components and combustion activities. Also, pool engine cooling systems are dangerous, especially when accelerating your car.

Therefore, this could be one of the results of checking the engine light flashing when you increase the car’s speed. Once the car computer detects overheating, it will send a signal on your car’s dashboard alerting you the engine is having a serious issue.

The faulty engine control unit

The Engine Control Unit is essential in the car to monitor fuel intake. When there is a malfunctioning of fuel system components, the ECU will receive the detections.

Upon ECU having some issues, it will be unable to control or monitor the fuel systems such as fuel injectors, and this faulty will make the check engine light start flashing.

Issues with camshaft sensor

The camshaft position sensor has the role of monitoring the speed and camshaft position in the car. Therefore, it sends such information to the car’s engine control unit for the ECU to manage the amount of fuel needed to enter the combustion chamber and spark timing for fuel ignition.

When you accelerate your car, there is a need for high adjustment of fuel intake and ignition timing. Therefore, having a bad camshaft sensor would mean poor rationing of fuel intake and spark timing, and this would be detected as an engine issue.

Most of the check engine lights under camshaft sensor circumstances may go on when the driver presses the gas pedal. The most likely cause of such a situation could be as a result of a faulty throttle position sensor.

Issues with charging system misfire

For your car’s engine to power properly even when you accelerate, there must be a specific operation order of fuel, oxygen, and ignition timing.

However, when there is a malfunctioning of one of the cylinders or all of them, the engine system will experience some issues then the check engine light will start flashing.

But in some circumstances, the check engine light flashing may appear as intermittent flashing where it will illuminate a little the stops, or the flashing exists as continuous illumination.

Such situations are not very serious, and you can drive longer before reaching your mechanic.

Possible solutions of a flashing check engine light when accelerating

While you accelerate your car and see a check engine light flashing, it indicates something is affecting your normal engine operation.

Therefore, you need to visit your mechanic for a check-up. If the causes could be engine misfiring, overheating, low oil pressure, ignition or spark plug issues, loose gas cap, oxygen sensor, or bad injectors, you need to replace the faulty parts.

The cost of fixing check engine light issues will vary depending on the type of fault and labor. For instance, it will cost you the following;

  • More than $50 to fix faulty spark plugs
  • More than $238 to fix the faulty oxygen sensor
  • Between $170 and $230 on fixing a faulty camshaft sensor
  • Average $900 on Engine Control Unit or Model replacement


When you see a check engine light flashing as you try to accelerate the car, whether it is a little flash, please don’t ignore it. Such warnings alert you that the car’s engine normally is not working in the right conditions; therefore, immediately call your mechanic to avoid further problems.

However, always carry a regular check-up on your car’s parts to avoid disappointments while in the middle of your journey.

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