Your car’s dashboard is equipped with many warning lights to tell you when something is wrong. The Check Engine Light might be one of the most recognizable, but most people see it come on as a solid light. In the rare times when the Check Engine Light is flashing, you need to know what to do next.
Throughout this guide, we discuss the main concerns to be aware of when you see a flashing Check Engine Light. We further discuss some steps you can take to resolve the issue. When you reach the end of our article, you will find answers to your top questions, such as if you should keep driving once the Check Engine Light starts flashing.
In This Article:
What Does A Flashing Check Engine Light Mean?
When there’s a concern with the engine or vital car systems, the Check Engine Light comes on to get your attention. The Check Engine Light can come on for hundreds of different reasons or trouble codes. Seeing a flashing Check Engine Light is much rarer.
When the Check Engine Light flashes, it designates that the problem is severe and must be dealt with immediately. There are only a handful of concerns that would lead to a flashing light, so it’s often easier to diagnose.
While it might be easier to figure out, the problems are normally much more difficult to deal with, often pointing to some level of failure that could be catastrophic if allowed to continue.
Causes of a Flashing or Blinking Check Engine Light
The most common cause of flashing or blinking check engine light is a misfiring engine, which can be caused by several different engine issues. Ideally, you will want to troubleshoot the vehicle and check the DTCs to find out what’s causing the issues.
For now, here are four possible causes worth considering.
1. Misfiring Engine
When an engine misfires, one or more of the cylinders doesn’t produce the power it should. A misfire can be caused by numerous problems, many of which can also lead to a flashing Check Engine Light. For example, you might be dealing with fouled-out spark plugs, a faulty oxygen sensor or a vacuum leak.
When the engine misfires, you notice a decrease in acceleration. The car can also start shaking when you try to go faster. It may feel like the vehicle loses power for a period. When it’s idling, the engine might feel like it’s vibrating more than normal. The trouble with a misfire is that it can occur intermittently or only when the engine is at a certain temperature.
It’s never wise to continue driving with a misfiring engine. At any time, the engine can quit working on you. Plus, you are allowing additional wear to other parts of the car. If that’s not enough, the engine is going to use more fuel and emissions will be increased during this time.
2. Low Fuel Pressure
The combustion chamber needs to have the right balance between fuel and air to ensure proper operation. If the fuel pressure is too low and the engine is starved of fuel, there could be serious problems. Low fuel pressure can be caused by bad injectors, a failing regulator, a broken pump, a clogged fuel filter, or a defective sensor.
When the fuel pressure is low, you might notice trouble accelerating. The engine could also misfire or stall as a result. Plus, it’s common to hear a whining noise with fuel problems. Allowing fuel pressure to remain low can put further wear on the engine and vital components.
3. Faulty Engine Sensor
Within the engine, there are a number of sensors working together to feed information to the computer. The computer takes this information to make decisions for better operation. If one of the sensors is bad, the computer is receiving faulty information. This problem can cause the computer to make decisions that shouldn’t be made, which leads to an imbalance and serious performance problems.
Some of the most common sensor failures include both the oxygen sensor and the mass airflow sensor. However, you could also be looking at a problem with the coolant temperature sensor or any one of the other high-tech features. The only way to know for sure which one is the problem is to scan the codes.
RELATED: 15 Types of Car Sensors (& What They Do)
4. Low Compression
For the engine to run, air and fuel must be present in addition to compression. The compression must reach an exact amount of pressure or there will be performance issues. With a lack of compression, the car can jerk, lose power and fail to accelerate.
Some of the top causes for compression issues include damaged piston rings, worn pistons, valve problems or faulty head gasket. However, the problem could also stem from a bad timing belt or chain.
How to Fix a Flashing Check Engine Light
It’s imperative that you stop driving immediately when the Check Engine Light starts flashing. Once you are pulled over, you can run through these steps to get to the heart of the issue.
1. Scan Trouble Codes
To fix a flashing check engine light, you need to read the trouble codes first. With your professional code scanner, you can read the DTCs that are set in the computer. You can use a variety of OBD-II scanners to figure out what’s going on, but some read more codes than others.
Additionally, if you don’t have your own scanner, there are other options. You can go to an auto parts store that offers free scanning services. When you find the trouble codes, you should continue the troubleshooting depending on which codes you find. We have a library here on Mechanic Base to research different trouble codes.
2. Inspect Spark Plugs and Ignition Coils
If the codes lead you to believe that the ignition system is to blame, you should take a look at the spark plugs. When carbon builds up on the plug, it can fail. The only solution is to replace the spark plug.
Additionally, if the code shows a problem with the ignition coils, you will need to replace these. The defective coil should be indicated by the trouble code.
3. Check Fuel Pressure
To check the fuel pressure, you can use a special gauge. Evaluate the normal reading through your service manual to see where it is supposed to be.
You can also use some advanced scanners to check the fuel pressure. If it is too low, you must diagnose what part is causing the problem and replace it.
4. Inspect Engine Sensors
You can’t physically examine every engine sensor on your car. However, the code scanner should help you determine which one might be to blame.
Once you pinpoint the sensor that’s bad, there’s a chance you can simply clean it off and reinstall it. Otherwise, a replacement will be necessary.
5. Contact A Professional
It’s important that you take the flashing Check Engine Light seriously. This warning light indicates that something major is occurring. For this reason, it’s sometimes best to consult with a professional.
You don’t want to take chances with something as important as your car engine. Whether you need help with diagnostics or repair, take time to search for a reputable repair shop that you can trust.
Can I Drive With A Blinking Check Engine Light?
While it might be okay to drive with a solid Check Engine Light, once it starts flashing, it’s time to stop. Continuing to drive could cause irreversible damage to the engine, which is why many cars will also go into a Limp Mode during this time. Pull over on the side of the road as soon as it is safe to do so.
Is It Worse If Your Check Engine Light Is Flashing Or Solid?
It’s never good to see a Check Engine Light. However, the solid warning light is often less troublesome than the flashing light. A blinking Check Engine Light typically indicates imminent failure that could destroy the car engine. For that reason, you should stop driving immediately.
Why Is My Engine Light Flashing And My Car Shaking?
Most of the problems that lead to a Check Engine Light flashing can also cause performance issues, such as shaking. Proper diagnosis will indicate if there’s a spark problem, trouble with the fuel delivery, low pressure or a malfunctioning sensor that is to blame.
Can Bad Spark Plugs Cause Check Engine Light To Blink?
As spark plugs start to foul, the Check Engine Light might not flash. There’s normally time to change the plugs before the problem gets that bad. However, if you let the plugs go unchecked, the engine will eventually misfire, which can cause the Check Engine Light to flash.
How Much Does It Cost To Fix A Flashing Engine Light?
The cost depends on what needs to be repaired. For example, new spark plugs might only cost $100, while low fuel pressure could range anywhere from $50 to $750 to repair. Additionally, malfunctioning sensors tends to cost $50 to $650, while low compression repair can quickly add up to thousands of dollars.
With a flashing Check Engine Light, you know there’s a serious problem that must be dealt with immediately. It could be caused by a misfiring engine or low fuel pressure. It can also be due to a faulty engine sensor or low compression. Either way, you should stop driving immediately.
There’s no room to hesitate because seconds could make the difference as to whether your engine becomes damaged or not. When the light starts to blink, find a safe place to pull over and turn the engine off immediately.
By taking swift action, you have the chance to prevent further damage. With a code scanner or through the help of a professional mechanic, you can figure out what went wrong and begin the repair.
Sources:
Learn more:
- Check Engine Light After Oil Change – Causes & How to Fix
- Check Engine Light On But No Codes – Causes & How To Fix It
- How to Reset a Check Engine Light (5 Easy Methods)
why is my engine light blinking and my car shakes when i drive and drive over 40 mph and drive highway ..
Write which car and engine model you have, and I could maybe help you with your engine issue.
I drive Camry 2.2 1999 when you remove the battery for some hours and put the battery wire back on again and start car and drive for at least 50 km the check engine will come on and then after a day or two my odometer and speed meter will just stop working and the car will have to struggle to change the first gear after it the first gear it runs normal after one or two hours the odometer and speed meter will come back on with check engine light! please help a brother.
Thanks for all the write up.
My opel vectra B always flash the check engine when I am on a high speed and when slowing down the engine offs by it self. Pls solution to this issue
hey magnus, i have a problem with my volkswagen 2009 golf TSI , engine light blinking during cold start or in the morning and it’s disappearing after 30 seconds.
i scanned it with the OBD and get a code misfiring cylinder no.1 and no.4,
i already change the coil and the spark plug but the code still appear the same, is there any possibility the fuel injectors went bad?
Hey magnus ,,, I’m in big trouble i drove Mitsubich Grandis 2006 model suddenly flashing engine light and did not rav losing power misfiring And I plug on the diagnostic it says throttle body/ pedal sensor permanent. But then I other new coils pack of 4 plus brand new throttle body when I replace the throttle body and coil the car did rav ‘ then after couple of minutes The engine started flashing again and the car did not rav what could be wrong sir please help thanks in advance
Hey Magnus, i just wanted to say thank you for your willingness to help people with their car problems… AND for FREE! You don’t find too much of that these days! It is much appreciated!
I have an 2003 honda civic 1.7 5 sppeed when you first start the car the battery light is on an the check engine will flast an can rev the car up 7000rmps but when the battery light turns off the check engine will turn to a solid an i loose rpms an car wont rev very high an theres power to the obo2 plug but cant pull nothing from the ecu
I have an 06 Nissan Altima 4 cylinder, the check engine light came on while driving and it was blinking but when I pulled over and turned the car off and retsarted it the check engine light was off. A week went by and then while driving the car shut off and would not start. Any ideas of what it could be? I’ve never had spark plugs replaced or had the timing replaced.
I drove a brand new dodge van, when I parked it, I turned off the van but left key on to listen to the radio, in less than a minute engine light began to blink, then it stood on constant. I turned key all the way to the left, and turned van back on and engine light was gone. Can the key turned to the right caused the engine light to blink?
2010 Honda Crosstour with 82,000 miles. Twice at 65-70 mph the check engine light flashes. Car drives fine. Dealership has checked for codes and there are not any. Sparkplugs were replaced at 70,000. Any ideas? Dealership recommends drive it until they can catch the check engine light blinking.
Good day, My name is Ibrahim, I was coming from office yesterday and I discovered my check engine was blinking , I need your advice on what to do.
I drive a Toyota Camry 2010 LE, 2.5 ltr. Check engine sing appeared. Machine read: Cylinder no. 1 misfires. Sometimes it starts flashing. When it flashes, the car doesn’t picks up instead of accelerating. But it becomes static gradually by releasing the accelerator. Or by stopping at the signal light point. Mechanic first changed 4 plugs. It did not resolve the problem. Then he changed the coil. But problem did not go. Now I am taking the car to the Toyota Dealer’s service station. I am afraid how much they will bill me. Although initially I am going to take it for diagnosis purpose.
Have you gotten it fixed and what did you fix ? I am encountering the same exact problem with the same car
Good day my car is not starting i took a wire from the fan to the egnitio and the wire touched the cars boddy while the egnition was on and it made a short now my engin light is blinking the engin turns but does not start. Opel corsa 1.4 itsa 2006model
I have Kia Opirus V6 2700 cc the check light starts blinking and when switch the engine off and restart again the car drives smooth and the blinking disappears and reappears again after a while with lose of engine power . On checking with scanner I was informed that miss fire was diagnosed in almost all engine units and I was advised to replace all spark plugs which I did. The car drove few miles and same symptoms reappeared with check light flashing and loss of power, Injectors seem to be OK as I was told by the mechanic . I would be thankfull if you would shed some light on what could be the problem.
Thanks
My 99 beetle sounded like the battery was dead I replaced the battery the starter and alternator are good the battery lite blinks and my car sound like the battery dyi g what is wrong with it susan
My car is in suddenly off engine light blinking
05 trailblazer a code came up po300 misfiring ok I change two coil packs n all 6 spark plugs .started it up n still running rough no codes came up like before but when you floor it check engine flashes let off gas it stops n goes off.n it smells bad when running could it be my catalytic converter stopped up causing it to do that
Did you ever find an answer to your problem?
I have an old Chevy 2008 impala that I use to tow an18 ft boat and use it only for that. The engine light has come on and it has been that way for months. Scanner shows code po172. Once in awhile light goes off for a day then comes back on. Now that it is warmer the engine light does not come on for the past week and I have been using it a lot around town for errands. The engine code is still showing up on the scanner and I have not erased it. The engine light comes on when I start the car and then goes off. Afraid to get stuck somewhere with the boat so I think I am going to put a hitch on both or one of the Rav 4’s. Do you think I should still use the Chevy if the light comes on again.
Have a 2002 Hyundai Elantra car have been having problems with suddenly shaking then stopping and now has a sulfur smell idles rough and check engine light is blinking?
I have an 02 Dodge Durango 4.7 L , it has recently popped a code PO302. Cyclinder 2 misfire. I have replaced the ignition coil module on cyclinder 2 & the throttle position sensor. However, after 3 – 4 days of driving it reappears again. What else could it be?
@Van Did you check the spark plugs on the affected cylinder? It could also be a wiring problem or a faulty injector (not very common though). I would check and replace the spark plug if you haven’t!
My engine light was on my 4 cylinder 2001 Honda CRV. I took it to Goodyear and they scanned at and said there were misfires on cylinders 2, 3 and 4. The car was driving fine though (4 hour drive on the way to the shop). They replaced spark plugs and wiring and then the engine light began flashing. They scanned it again and it’s saying there’s random misfiring now. I had to drive it home from Charlotte, NC to Atlanta, GA and now problems with the car or engine temp… Any recommendations on what to do next?
@Amy C
Random misfires are often caused by a faulty fuel mixture. Common things for a lean mixture is an intake leak/PCV valve problems. It can also be caused by low fuel pressure in the pressure rail. However, I would begin with checking for intake leaks and make sure that the PCV valve is in good condition.
Hi
In our country the rain made lakes in all our roads so i drived in some water lakes on certain road and the water was minimum 50cm high and it entered my car honda accord model 1988 and when i reached my home it suddenly turned off and would turned on again because the check engine is blinking and there is other devices next to the engine are blinking noise sound. So what shall i do?
You should absolutely read the trouble codes with a scanner and see what it says. Most likely you can erase the codes and keep driving as there was maybe bad connection in the wirings caused by the water.
Friends,
I have a 2005 Subaru legacy SOHC 2.5L engine that went bad. I was told by the store selling me an engine that I could put a 2.0 SOHC in and it would fit and work perfect. I replaced the motor and the 2.0 fit perfectly! Now the bad. However my check engine light is flashing! I took it to my auto pros (a different shop) and they put a factory obd machine on it and said they were stumped as there are NO OBD codes! They said the car runs fine as they checked it out. However no OBD Codes. A BIG, HELLLP! Any feedback Master of the Mechani internet Universe?
Either the instrument is not working together with the engine control unit if you replaced it, or there are stored trouble codes but the code scanner could not read these.
I would recommend using a Subaru code reader if possible. Some scanners can’t read manufacturer codes! 🙂
Did spark plugs affect Engine flashlight for Opel corsa hatchback?