Check Engine Light Flashing And Car Shaking (Causes & Fixes)

If you are like me, the check engine light in your vehicle is enough to induce intense stress or frustration. When accompanied by shaking, the check engine light can indicate a serious issue. Luckily, I have compiled all of the information you need to address your issue.

The check engine light flashing and your car shaking means that your engine is misfiring. An ignition coil, spark plugs, or an engine sensor could be defective. The problem could also be the fuel supply. The idle air control valve may be malfunctioning if the car shakes only when idling. It is not advised you drive the vehicle until the issue is resolved.

This guide will detail all of the main causes of engine misfires and flashing check engine lights accompanied by a shaking vehicle.

Why Is Your Car Shaking And The Engine Light Going Off?

A malfunctioning cylinder is the primary cause of your check engine light blinking and shaking. Every cylinder in your engine has a role to play in passing the mixture of fuel and air through the system. A misfire occurs when the cylinder fails to pass fuel and air every time the crankshaft turns. This results in a rough engine and a shaking car.

How Does Engine Misfire Feel?

It feels as if your engine is suddenly losing power when you experience a misfire. If you try to accelerate the vehicle, you may experience a hesitation. A misfire in your engine could be the cause of a vehicle accelerating slowly or feeling rough.

What Are The Main Causes Of A Check Engine Light?

The flashing of the check engine light, coupled with a noticeable shaking of the vehicle, is a key sign that there has been a cylinder misfire in almost all cases.

In the case of an engine misfire, the term could best be defined as a partial or complete loss of combustion on one or more of its cylinders. Even though it is rarely difficult to identify the misfire as the root cause of any of the symptoms mentioned above, it is generally much more difficult to identify the actual source of the misfire itself.

A cylinder misfire can be caused by a variety of factors, some of which are listed below.

Faulty/Damaged/Fouled Spark Plugs

A spark plug is an important component of an engine since it is responsible for delivering the necessary spark needed to ignite combustion within each individual cylinder of the engine.

It is inevitable that spark plugs can become fouled over time, or they may have an incorrect gap, which will make it difficult, if not impossible, to ignite the engine. Consequently, this leads to the initiation of a misfire, which can only be corrected by proper maintenance of the machine.

When it comes to preventing future misfires, it is vital to always be aware of the condition of your spark plugs (and replace them when they become worn out) on a regular basis.

Compromised Coil-Packs/Plug Wires

There are some different ways that a spark plug wire, or an engine with a coil-on-plug ignition system, a coil-pack, is used to deliver the spark plug’s ignition power to a cylinder.

It is possible that over time, and as a result of exposure to the engine’s heat, the insulation outer sheathing of these components will become brittle and crack, allowing the ignition power to leak into the ground as a result.

Damaged/Corroded Distributor Cap or Faulty Ignition Coil

There is also a possibility that a partial failure of an engine’s distributor cap or ignition coil could contribute to an active misfire.

Such equipment was used by many older internal combustion engines to time the delivery of sparks to each of the cylinders in order to prevent overfiring. A common problem with distributor caps was their tendency to crack and corrode, while coils were often susceptible to failure caused by excessive heat.

Fuel-Delivery Issues

An engine misfire can also be caused by faulty fuel injectors. When a fuel injector fails mechanically or electrically, fuel cannot be dosed to a particular cylinder, preventing fuel from being injected into the engine.

This, in turn, results in no catalyst for combustion, which, consequently, robs a cylinder of its ability to produce power. As a result, there can often be noticeable shaking that can be felt quite easily as a result of this. You may even see the check engine light flashing as well as problems with the fuel delivery system can cause a variety of problems.

Compression Loss

A misfire condition can occasionally be caused by a loss of compression on one or more cylinders of the engine, which occurs on a less regular basis. As a general rule, this issue tends to be more prevalent on engines that have high mileage, or those that are of an older vintage.

As a result of compromised piston rings, damaged pistons, or valve-related problems, compression loss can occur. Sudden compression loss can also be caused by a severe failure of the head gasket.

Emissions-Control Induced Misfires

There are also instances when the emissions control devices in an engine can malfunction or be marginalized, resulting in an engine misfiring on one or more of its cylinders on a constant basis. The most frequent cause of this issue is the stuck open position of the EGR valve which is most often caused by a stuck EGR valve.

As a result, excess exhaust gases are recirculated into an engine’s intake in order to re-combust them in the engine’s intake. This results in oxygen saturation levels falling below optimal levels, thereby impeding the efficient combustion of the fuel.

This type of misfire is more likely to occur, at random, on a number of cylinders, rather than on one cylinder at a time. The reason for this is that exhaust gases are circulated indiscriminately between each of the cylinders of an engine, which results in excessive exhaust gases being released.

Now that we have covered all of the main causes of engine misfires, it is important that we discuss the difference between a flashing engine light and a steady one. This will help you determine when you have an issue.

What Is The Difference Between A Flashing Engine Light And A Steady One?

A check engine light can present itself in two different ways, the first of which is the one whose intensity is steady, the second of which is the one whose intensity is fluctuating. It is also possible to have a check engine light that blinks repeatedly at a set rate in addition to the previous type.

In most cases, you will find that the latter of the types of check engine lights is signifying of a more serious problem that is currently in progress.

The presence of a solid check engine light indicates that a diagnostic fault code has been logged and stored, regardless of whether it is currently active or not. The purpose of a blinking check engine light is most often to convey a set message to a motorist that he/she needs to pay attention to.

In most cases, this message refers to the fact that a current misfire has been detected in one or more specific cylinders, and an error message has been issued. So now you may be wondering, is your vehicle safe to drive in this condition? This will be covered in the next section.

Is It Still Safe To Drive?

You should not drive further than necessary to reach your safe destination when your car’s check engine light is flashing and shaking. This light can be more serious than a “service engine soon” light.

It has been mentioned above that symptoms of this nature are most often associated with engine misfiring or partial/complete loss of combustion of one or more cylinders of an engine.

When a misfire occurs, it is not only an indication of subsequent performance loss but also foreshadows a number of secondary problems that can occur in the future if the misfire itself is not properly addressed, as it often foreshadows a number of secondary problems.

An example of such a problem is that of damage to the catalytic converter of a vehicle, which results in the exhaust of the vehicle being contaminated with excess fuel, due to a lack of spark in the engine’s exhaust system.

It is essential to diagnose and fix the root cause of a vehicle’s misfire condition as soon as possible, no matter how severe the misfire condition is. As a result of doing so, further issues will not be able to arise, many of which may prove to be rather expensive to resolve in the future.

It is advisable to make an appointment with a good independent mechanic or dealership service center as soon as you can if you don’t feel confident enough in diagnosing the problem and fixing it yourself.

Car Shaking And Check Engine Light On After Oil Change

The shaking of your car and the check engine light on the dashboard are both signs that your engine is misfiring and needs to be repaired.

Most of the time, this problem is the result of faulty spark plugs or an excessive amount of oil being poured into the engine. You should remove some of the oil and see if that resolves your issue.

Once you have identified your issue, you will need to know the best course of action to resolve it. This will be covered in the next section of this guide.

How To Fix A Flashing Engine Light And Shaking Car?

Luckily, if the check engine light in the dashboard is blinking, it almost certainly indicates there is an engine trouble code stored in the ECU of the car. In order to identify the problem, it is very important to run a diagnostic using an error code reader in order to address the problem. This will enable you to get a better understanding of where the problem lies.

In case the error code shows that there is some problem with fuel pressure, then you should try to change the fuel filter and check the fuel system for any blockages or leaks that might be present.

There can be times when it is more difficult to diagnose the problem if there is not a specific error code indicating a particular component like the fuel pump, fuel rail, or fuel injector, particularly if replacing the fuel filter does not resolve the issue.

When you receive an error code such as P0301 to P0304, it is usually an indication that there is an issue with the ignition of the fuel inside of the cylinder. In most cases, the spark plugs can be changed and the ignition coils can be checked to see if they are all working correctly to rectify this problem.

If your engine sensor fails, there will usually be a specific error code associated with it that you can check online. The most common solution to this type of problem is to replace the sensor that is causing the problem and to clear the trouble code from the ECU memory.

In most cases, you can identify a bad idle air control valve by noticing that it goes away when the vehicle is moving. There is usually an error code of P0505 associated with a faulty idle air control (IAC) valve. The IAC can also be tested in order to assess how well it responds to changes in engine conditions or a change in RPM by performing a number of tests on it.

Now that we have covered the basics of engine lights and your car shaking, you may be curious to know how much you can expect to pay to have this issue fixed.

What’s The Cost To Get This Fixed?

It is important to note that engine misfire repair costs vary depending on the vehicle’s make, model, and year. A misfire in an engine is also costed according to its nature. There is the possibility of paying a low or very high price.

It will usually take an hour to replace a spark plug, in addition to the parts, which are usually inexpensive. In the same way, you can expect to pay around $300, not including labor, to replace the ignition coil.

A significant problem with your engine, on the other hand, will result in a higher cost. The cost and time of repairing a blown head gasket, for example, are high. It could cost you hundreds of dollars to replace your car’s catalytic converter.

Finally, some frequently asked questions will be detailed in the sections below to better help you address any issues you still may be having with your vehicle.


Is It Safe To Drive When Your Car Is Shaking And The Check Engine Light Is On?

If your notice that your check engine light is blinking, you should not drive your car. Your check engine light is telling you that there is an issue with the engine. Continuously blinking or coming on and staying on are both possible.

It is important to investigate any problem as soon as possible if the check engine light is blinking. To prevent further engine damage, you should not drive the vehicle.

Normally, a blinking check engine light indicates that the engine is misfiring continuously or that the timing is off. Fuel pressure drops or overheating can also cause it.

When the check engine light remains static, it normally indicates that an engine sensor is failing or that the engine is intermittent. Driving the car is usually safe, but you should get it checked out or run an ECU diagnostic.

Why Does My Car Shake When I Press The Gas Pedal?

Many factors can cause a car to shake when you press the gas pedal. Any minor vibrations or shaking will be amplified when you press on the gas pedal, making them more noticeable.

It is most often the engine that causes your vehicle to shake when you tap the gas pedal. An engine misfire may be caused by a lack of fuel or an issue with one of the spark plugs. Exhaust systems can also cause the problem.

Final Thoughts

Your check engine light flashes when there is a problem with your engine. When the engine light only illuminates, the problem isn’t major and won’t cost much to fix. However, if the light is constantly flashing, your vehicle might be experiencing a serious engine problem, and you should tow it to a mechanic as soon as you are able.