Chevy Check Engine Light Flashing Then Stops: Why It Happens

Having your Chevy check engine light flashing then stops can be disturbing. A check engine light is designed as a warning signal that indicates an issue with your engine. Although this light can come on for even the most mundane issues, you shouldn’t ignore this sign at any point.

Chevy Check Engine Light Flashing Then Stops


In this guide, our automobile team will discuss the reasons for this experience and how to correct the problem.

What Are the Causes of Chevy Check Engine Light Flashing Then Stops?

The causes of Chevy check engine light flashing then stops might include a problem with your engine, spark plugs, and even fuel injectors. If your engine light comes on or flashes intermittently, your car needs attention. However, a constant or flashing engine light signifies a serious mechanical issue.


When your check warning signal flashes ten times, your engine is in a bad state and likely to misfire. Once you notice this, you should immediately consult a professional mechanic to fix it, as it can cause serious damage to your engine if left unattended.

Here are ten common causes of a flashing engine light.

– Ignition Issues

Bad ignition coils are one of the most common causes of a flashing engine light. The coils convert low currents to a higher voltage that powers your car’s plugs and ignites the fuel. Unfortunately, it is almost impossible to know when the coils or coil packs are damaged because they don’t often appear damaged.

However, a tell-tale sign of bad coils is that you experience ignition issues like car stalling, poor fuel economy, and rough idle. In addition, you may notice your car shakes and engine misfires from time to time. At this point, your warning light will also come on.

– Loose Fuel Cap

A loose fuel cap is another common cause of a flashing engine light. Also known as a gas cap or petrol cap, this aids the functioning of your fuel system by keeping it sealed from the outside air. Since your engine works with fuel vapors, a petrol cap prevents these vapors from escaping. If your petrol cap becomes loose or broken, then a leak will surely occur.

As a warning sign, your check engine light will naturally come on to indicate this leak. One of the most tell-tale symptoms of a loose cap is that you will start to make more stops at the gas station. You’ll also notice that your car emits more smoke than usual.

– Bad Airflow Sensor

Commonly known as a mass air flow sensor (MAF), this controls the amount of air being let into the engine and ensures the fuel-air ratio is balanced. If your MAF sensor is dirty, worn, or damaged, it will be unable to detect the correct amount of air in the engine. 

Once this happens, one of the most common indications is that your warning light comes on. You may also detect difficulty when accelerating, and your exhaust system will start to emit black smoke.

Your car would also start to jerk, hesitate, or rough idle at the most unexpected times, and its fuel efficiency will drop. Although it requires a simple fix, a bad MAF sensor can cause serious damage to your engine if left unattended.

– Bad Timing Belt

A timing belt is considered one of the most important parts of a car’s engine, and when it is bad, the engine won’t work. When dealing with a worn timing belt, you will notice your car sputtering or rattling when you turn on the engine. You may also notice that your occasional engine misfires, and overall, your car’s performance is compromised.

When all of these occur, you’ll notice your check engine light blinking on your dashboard. Occasionally, your engine may lose power or idle more roughly than usual.

– Faulty Catalytic Converter

A faulty catalytic converter is another possible reason you have a blinking check engine light on your dashboard. A catalytic converter converts dangerous gasses from the exhaust into less toxic gasses capable of causing harm to humans and the atmosphere. Unfortunately, when this converter becomes clogged with dirt or fails, it cannot carry out its function properly. Hence, your warning light will indicate this problem with your exhaust system.

A bad converter is mostly followed by a burning smell that can be detected right inside the cabin of your car. Your engine would start to overheat and become slower in performance. You will also notice trouble with acceleration and the emission of heavy black smoke from the exhaust pipe.


Faulty Oxygen Sensor

Commonly known as an “O2 Sensor,” this carries out the role of ensuring the right amount of oxygen is present for combustion to take place. When the O2 sensor is faulty, your vehicle cannot perform well because there isn’t enough oxygen to carry out the combustion process efficiently. Hence, your warning light will be triggered and will come on.

You’ll also notice a sulphuric or rotten egg smell from your car whenever the engine is turned on. Its fuel efficiency also significantly reduces, and you will notice your car jerking, stalling, and occasionally losing power. These are signs of a bad O2 sensor, and it requires urgent attention before serious harm is done to your engine.

Bad Spark Plugs

Faulty or damaged spark plugs also trigger a faulty ignition, which can cause your check engine light to start flashing. These plugs create an electrical spark that, in turn, ignites the fuel-air mixture in the engine’s cylinder, allowing the engine to run.

A spark plug can become faulty when clogged with dirt or residual carbon buildup. It could also be rusted, corroded, or burnt due to overuse, and when this happens, your engine will start to misfire. Your engine won’t be able to run properly with faulty plugs, and it is only natural that your engine light codes will appear on your dashboard.

Fuel Delivery Issues

If the engine doesn’t get the right amount of fuel needed to run, it won’t perform optimally. There are several reasons why you may experience fuel-related issues, and one of them is having bad fuel injectors.

Car Fuel Delivery Issues

These injectors are controlled by the engine computer and work by injecting the fuel needed into the engine’s cylinders via a nozzle. Over time, these can be clogged with dirt, making it hard to deliver the right amount of fuel to the engine.

Another reason why you may be experiencing fuel-related issues is that your fuel filters are clogged or worn out. This filter allows fuel to run smoothly to the engine without contaminants or particles disrupting this process. In this case, your fuel pressure will be compromised, and your warning light will start flashing to indicate this.

– Failed Engine Computer

The engine computer, also called the engine control module (ECU), is an essential vehicle component. The ECU collects data from various parts of the engine and uses this information to enhance the efficiency and performance of your car. The engine computer is also responsible for sending information to your check engine light unit when there’s a problem.

However, there are times when your ECU will start having glitches or failing, causing it to send incorrect data to your check engine light. In such a case, your engine light will start flashing or remain illuminated even when there’s nothing wrong with the engine or other parts of the car.

– Gasket Leaks

A gasket prevents oil and other liquids from spilling into the engine and causing damage. When your head gasket is broken or blown, it’ll cause leaks capable of disrupting the performance of your vehicle’s engine. Even if it’s just a little leak, your check engine light would likely come on.

Other signs of a gasket leak include muffler or tailpipe leaking water, whitish smoke coming from your exhaust, and low coolant levels. You may also notice that your engine overheats, misfires, stalls, and idles roughly more than normal.

What Are the Fixes for Chevy Check Engine Light Flashing Then Stops?

The fixes for Chevy check engine light flashing then stops include replacing the leaking gasket, MAF sensor, timing belt, and O2 sensor, but these are not the only fixes for this issue. You can also try fixing the ignition issues or replacing damaged spark plugs.

Fixes for Chevy Check Engine Light Flashing Then Stops


Your car is shaking and your warning light is blinking because there’s a problem with the timing belt or MAF sensor. It could also be that your engine is overworking itself due to a faulty O2 sensor or improper fuel press. All of these will cause your car to shake, and your warning light will start to blink.

Below are the best fixes for a flashing check engine light.

– Fix Ignition Issues

If your ignition coil or coil pack is deemed faulty, immediately replace it with a new one. You may also need to change the ignition switch, keys, and other causes of ignition failure. Before doing this, you must consult a professional mechanic to be sure your ignition is responsible for the check light coming on. Once parts of the ignition that need fixing have been repaired or replaced, you’ll notice your warning light will stop flashing.

– Tighten Loose Caps

If your petrol cap appears loose, you should immediately tighten it to prevent fuel vapors from leaking out and causing your engine to malfunction. Once you’re certain the caps haven’t been damaged, you can tighten them with your hands until you hear a clicking sound. However, if the caps look worn or broken, it is best to replace them with new ones.

Neglecting to do this would lead to further damage. Once these are in good condition, your ECU will communicate this data to your engine, and the check light should stop flashing.

– Fix MAF Sensor

If you notice your engine light blinking intermittently, it may be your sign to repair or replace your MAF sensor. Since an improper fuel-air ratio can cause your vehicle to malfunction, you should fix the sensor when it is diagnosed as a problem. However, fixing a bad MAF sensor can be quite technical, so it’s best to leave this task to an experienced automobile engineer.

Naturally, once your MAF sensor is working as it should, the combustion process becomes easier since the right amount of air and fuel is present in the engine. Once your engine computer detects this, it will relay this information to your warning light, which will stop flashing immediately.

– Replace Bad Timing Belt

Once you notice that your engine misfires a lot and your warning light is on, it is a sign that you may need to check your timing belt. First, you’ll need to check whether it’s worn or completely broken.

If your timing belt is broken, you’ll need to replace it with a brand new one, which can be expensive. Replacing a timing belt is expensive because it requires taking out other parts of the car, which increases labor.

Sometimes you may even have to change the car’s water pump. Whatever the case is, ensure you get the right diagnosis from your mechanic before carrying out repairs.

– Fix Bad Catalytic Converter

Once you’re certain that a faulty converter is why your check engine signal is blinking, you should fix it as soon as you can. The first step you should take is check to see if the converter is clogged with dirt or has been damaged. If the converter seems in perfect shape but isn’t working due to the buildup of carbon deposits and smoke, you should clean it.

Get a converter or throttle cleaner from any automobile shop and pour it into your car’s engine. Then take a drive for as long as necessary to allow the cleaner to circulate throughout the converter until it is completely clean. If the converter is damaged, the best option would be to replace it with a new one.

– Replace O2 Sensor

An O2 sensor is a crucial car component that doesn’t get spoiled easily. That is, they do not require regular maintenance or repairs to function. However, once it gets bad, you need to pay urgent attention to it and fix it immediately. Although some people would recommend cleaning the O2 sensor to get it to work, this doesn’t fix anything.

Unfortunately, an O2 sensor can’t be repaired due to the intricacy of its design, so a replacement is the only option. Repairing this sensor can be expensive or cheap, depending on the model and type of car you drive. As expected, high-end vehicles would surely cost more in terms of repairs and maintenance.

– Replace Damaged Spark Plugs

Replacing a bad plug is one lasting solution to eliminating a flashing check engine signal and ignition issues. First, you must take out the old plugs and inspect them for damage. If the ends look smooth and even, you don’t necessarily need to change them. However, if the plugs look burnt or crooked, you should replace them immediately.

Although it is possible to replace your plug yourself, you need great technical skills to do this without causing further damage to your vehicle during installation. Hence, we recommend contacting a professional mechanic to perform this task efficiently.

– Clean or Replace Filter and Injectors

If you are certain your gas filter and injectors are clogged with grime or contaminants, the first thing to do would be to clean them as thoroughly as you can. You can do this with a cleaner and neat rag. Make sure you clean the filters and injector nozzles to ensure that they don’t block fuel from flowing smoothly to the engine.

However, if both are worn out and damaged, replace them with a new one. Your check engine signal should stop flashing once this problem has been resolved.

– Fix Failing Engine Computer

A failing engine computer can cause your check engine signal to blink, causing a false alarm. If you are certain your car’s engine is in perfect working condition, you may need to focus on the ECU. The easiest way to troubleshoot this would be to repair or reprogram it.

Contact a professional mechanic to carry out tests on the computer first. If the issue is from the ECU, you can then clear the false codes.

– Fix Gasket Leaks

A leaking gasket can disrupt the smooth operation of your vehicle. Once you see that it is leaking, consult a professional mechanic to check it and carry out repairs.

You should note that not all gasket leaks require the service of a mechanic. There are gasket repair solution products available in many automobile shops. These could work in fixing your leaks if they are not too serious. But if your gasket is severely damaged, you’ll need professional service, which can be quite expensive.

– Go for an Oil Change

A check engine signal can come on for an oil change. When this happens, it means your oil is insufficient, worn out, or dirty. You’ll need to replace or top it off, and you have to make sure you’re using quality oil to enable it to flow properly.

Frequently Asked Questions

1. Can I Drive if the Chevy Check Engine Light Keeps Flashing and Then Stops?

Yes, you can drive if the Chevy check engine light keeps flashes and then stops. A warning light indicates an underlying issue with your car but doesn’t necessarily connote serious problems. However, you shouldn’t drive your car if your Chevy warning light continues to flash without stopping.

Doing this could be potentially dangerous for both you and your vehicle’s engine.

2. How Much Will It Cost You To Fix a Chevy Flashing Engine Warning Signal?

It will cost you around $500-$2,500 to fix a Chevy flashing engine warning signal, depending on the damage. Changing parts like the plugs can be inexpensive, ranging from $20-$50. You’ll pay more if you’re fixing a blown or leaking gasket, a MAF sensor, or even a converter. 

The amount you’d spend on repairing a flashing warning sign depends on the parts of the engine that need fixing and their severity. 

3. Why Does Your Chevy Check Engine Signal Flash When Accelerating?

Your Chevy check engine signal flashes when accelerating because it indicates a problem with the fuel supply in your engine. In this case, you’ll need to fix or replace your injector or filters. Other times, it could be that your converter is bad or your gas cap isn’t tightened.

Chevy Check Engine Light Flashing Then Stops Conclusion


Now that you understand the possible reasons why your warning light keeps flashing intermittently, you don’t have to waste time fixing it. Here’s a summary of the key points we discussed in this article:

  • If you notice your Chevy check engine light flashing then stops, it could be due to ignition issues, bad plugs, or a faulty O2 sensor. 
  • A worn or broken timing belt, a failing engine computer, or a gasket leak can also cause the CEL to flash and then stop.
  • You can resolve these technical problems by replacing damaged plugs, tightening the loose caps, and repairing your MAF sensor and timing belt. 
  • Fixing your ECU and gasket leaks will also stop your warning lights from blinking.
  • Always ensure you get a correct diagnosis from a certified mechanic before carrying out any repairs.

Now that you can identify why your warning light is turned on, you should be able to streamline the specific cause and resolve it immediately!

5/5 - (14 votes)
Ran When Parked