If you ever had your check engine light flashing, then depending on how it is flashing, you can determine the severity of the issue. Is your check engine light flashing while driving? You might need to shut down your car directly!
⚠️ If It's Broken, Don't Fix It - Get Paid Cash for Your Vehicle ⚠️
If the light is illuminating continuously, then it should be a simple issue and no need to fix immediately; however, if the light is blinking, you must stop driving and tow your car to the mechanic quickly.
Many issues could cause the check engine light to flash, including fuel mixture issues, ignition system problems, and low compression issues.
Most of the time, a flashing light engine is due to an engine misfire. Therefore, in this article, we will focus mostly on engine misfire issues that cause check engine light flashing.
By reading this article, you will be able to answer many of the questions you have like what does a flashing check engine light mean? Why are my check engine light flashing and car shaking? What are the causes of a flashing check engine light? How much does it cost to repair issues causing the engine light to flash? So, keep reading to know more!
What Are the Different Types of Engine Light Illuminations:
The check engine light is an indication of an issue with your engine. The severity of the effect depends on how the light is illuminating. There are three common ways for how the check engine flash illuminates:
- Continuous illumination: when the engine light is simply on, meaning it is not flashing, there is no major issue in your car, and the fix should be very cheap and straightforward. It could start with check engine light flashing then stable.
- Intermittent illumination: if the check engine flashlights for a little bit and then it turned off by itself, this is considered a soft failure. The mild failure is associated with specific conditions (e.g., if a wire is broken and keeps connecting and disconnecting, the check engine light will turn on and off accordingly.) Think of it as: check engine light flashing then stops.
- Continuous flashing: if the check engine light is continuously flashing, this is an indication of an emergency. You need to stop the vehicle right away and call a towing to take the car to a professional mechanic.
What is An Engine Misfire?
The car engine contains a group of cylinders where the air and fuel mix and ignite to provide the power to drive the vehicle.
If one or more cylinders had an issue and were not able to work correctly (e.g., the automobile couldn’t burn the fuel, the air/fuel ratio was not accurate, ect.), then the check engine light will start flashing.
If you are wondering why my check engine light is flashing? It might be an engine misfire.
What are the Symptoms of Engine Misfire?
If the check engine light flashes, you will notice right away that the car is not performing as usual, especially at higher RPMs where the vehicle starts to be bumpy or jerky.
Below are some of the symptoms that can tell you there is an engine misfire:
- Engine Sound: one of the first things you can quickly notice an engine misfire is the weird sound of your engine. The engine could be jerky or drives roughly, telling you to stop driving and collect more clues to know what is going on. In some severe scenarios, you might experience check engine light flashing car sputtering.
- Gas Smell: the other obvious thing you should pay attention to is any gas smell in the car. The gas smell plus a flashing check engine light can indicate that there is a leak in your fuel, and the problem could be severe.
- Rough Idle and Acceleration: if the engine is experiencing misfire, you will notice that it is hard to accelerate or idle. The car will not behave as usual at lower RMP due to some issues in the air/fuel mixture. In this symptom, you might notice something like check engine light flashing when accelerating.
- Vehicle Shake: if one of your engine cylinders is not working, this will cause unbalance in your engine behavior, and therefore, the unbalanced engine can cause the cabin to shake or vibrate. In this scenario, the check engine light flashing car shaking.
- Reduction in Vehicle Power: when the air/fuel mixture does not have the appropriate air to fuel ratio, the car will not be able to accelerate, and it can barely get to 3,500 RPM.
- Some additional engine misfire symptoms include difficulty starting the car, black smoke coming out of your tailpipe, and rotten egg smell coming out of your exhaust.
What are the Causes of Engine Misfire?
Engine misfire has to due with an issue with your car engine. The engine consists of many parts that, if it had a problem, the engine light would start flashing. Some of these causes are illustrated in detail below, and other issues are also listed towards the bottom.
Here is the list of the 20 most common reasons for a check engine light flashing
- A Problem with the Oxygen Sensor: the oxygen sensor is responsible for monitoring the oxygen level in the exhaust. The oxygen level in the exhaust information is used to determine the required air/fuel ratio in the cylinder. Imagine if there is an issue with this sensor, the engine will either have more fuel or more air than needed.
If the air/fuel mixture had more fuel than required, the ignite would not be able to burn this fuel, and some of it might leak through the exhaust, or it can cause other significant issues.
- Faulty Fuel Cap: you will be surprised to know that if your fuel cap is not closed correctly, your engine light will illuminate. While this might be a simple issue with an unclosed cap, the fuel cap might be broken and needs to be replaced.
Either way, engine misfire due to problems with fuel cap is very cheap and easy to fix.
In this issue, you can simply try to close the fuel cap securely and drive the car for a little bit. If the check engine light is still illuminating, then the issue is much more complicated than closing your fuel cap. In this scenario, you need to stop driving your car and call the towing.
- Faulty or Failed Catalytic Converter. This is one of the worst scenarios to happen if your check engine light is flashing!
The catalytic converter is responsible for converting the bad emissions from the combustion engine into less harmful gases before they leave through the tailpipe.
If there is an issue with your car’s catalytic converter, you must stop driving right away and call a towing service. You will find most likely to have a very pricy engine fix (e.g., the catalytic converter can cost ~$500 to $1,000, some cars have four of them).
- Failed Mass Air Flow (MAF) Sensor:
The mass airflow sensor is responsible for controlling how much fuel should be added to the air/fuel mixture. This sensor might fail due to simple issues like a dirty air filter.
Fixing a mass airflow sensor is not an emergency; you can still drive your car. However, a failed mass air flow sensor can significantly affect your fuel economy, resulting in low car performance, and cause a rough engine when accelerating.
To fix your MAF sensor, you must take your vehicle to a professional mechanic as it is relatively more complicated than the other issues causing an engine misfire.
- Spark Plugs Issue: spark plugs should be changed as part of your regular car maintenance. If you do not follow the maintenance schedule from your mechanic, you might have a scenario of burnt or faulty spark plugs causing the engine light to illuminate.
- Failed Ignition Coil: the ignition coils are responsible for converting the voltage into volt, forcing the spark to ignite the air/fuel mixture. If you ever had faulty ignition coils, it is recommended that you check/replace your entire ignition system.
- An Issue with the Charging System: experts recommend that you check your engine’s battery frequently to avoid needing a jump start for your car.
- Engine Overheating: the high engine temperature is an indication of significant issues happening with the engine. Therefore, if you confirmed that the driver is overheating, you need to shut down your car and request service.
- Cylinder Gasket Failure: another major issue that you need to do your best to avoid. A failed cylinder head gasket can cause the engine oil or the coolant to leak to the cylinder. If the engine oil or coolant leaks to the cylinder, a complete engine failure might happen, and fixing it, if possible, is very costly.
- Low Compression Issues: if there is a leak in the air/fuel mixture, the cylinders will not have enough pressure, and therefore, you can experience a shaking vehicle, low power, and very slow acceleration.
- Piston Head Failure: the piston head failure is another common reason for engine misfire that causes a check engine light flashing. Fixing a piston head failure is very pricy.
- Faulting Ignition Wires
- Issues with the Timing Belt
- Faulty EGR Valve
- A clog in the Fuel Filter
- Issues with the Electric System
- Faulty Crankshaft
- Internal Engine Problems
- EVAP Issue
- Faulty Control Unit
How Much Does It Cost to Fix Engine Misfire or Flashing Check Engine Light Issues?
While the cost of repairing engine misfire depends on the car make, model and year, there are some typical prices to give you a rough estimate of the range of cost to expect.
Besides, the price of fixing the engine misfire depends on the issue. You could either pay meager costs or pay extremely high costs.
For example, if you are to fix the spark plug, this will require about an hour of labor in addition to the parts costs (usually cheap). Similarly, if you want to fix the ignition coil, you might pay about $300, including labor cost.
On the other hand, if the issue in your engine is dominant, the price is much higher. For example, if you have a blown head gasket, it is costly and very labor-intensive. If the issue is with your car’s catalytic converter, the price gets to thousands.
In this table, we summarized the most common check engine flashing light issues and their associated prices:
| Engine Issue | Estimated Price |
| Damaged or loose fuel cap | $5.0 |
| Oxygen sensor | $150.0 |
| Spark plugs or wires | $100 – $200 |
| Purge control valve | $150 |
| Purge solenoid | $160 |
| Ignition coil | $220 |
| Thermostat | $250 |
| Mass airflow sensor | $250 – $450 |
| Fuel injector | $450 |
Bottom Line
A flashing check engine light is an indication of an issue with your engine.
If the light is just illuminating, the engine issue is not an emergency and does not generally cost a lot to be fixed. However, if the sun is continuously flashing, this is an indication of a major engine problem, and you must pull over as soon as you can and tow your car to a professional mechanic.
A flashing engine comes along with other symptoms, including a shaking or vibrating vehicle, jerky engine sound, rotten egg smell coming out of the tailpipe, white or blue smoke coming out of the exhaust and much more.
The car computer will generate a code describing the problem. You could get a tool to explain to you what does this code mean, or you could simply ask a professional mechanic to explain it to you.
The price of fixing issues causing a flashing check engine light varies by car make, model, year, and by the cause of the problem. The cost can range from a couple of dollars to a couple of thousands of dollars.
Whenever you experience a flashing engine light, check how it is flashing, get it fixed right away to avoid further damages.