What the Check Engine Light is Trying to Tell You

Trying to figure out what is going on in your car can feel like trying to deal with a wild animal. Sometimes they can purr peacefully in response to your touch, and other times they can viciously show their teeth. The check engine light is a car’s way of doing the second one. And just like an animal showing their teeth, it is dangerous.

Lots of people know that the check engine light is a serious thing, but not very many people know why that is the case. Sadly, as a result of this lack of education, many people might be consciously aware of the fact that the check engine light is serious, but they do not feel it. It does not alarm them like it should.

For that reason, Tommy’s Hi Tech Auto Repair has made this guide for understanding what the light means.

The Easy Answer: A Loose Gas Cap

When you start your car, all the lights on the dashboard will come on. Then, the ones that actually have something to report will stay on. If the check engine light is on it will mean one of two things: A serious problem, or a problem with the gas cap.

The first thing you should do if you see the check engine light is go and make sure your gas cap is screwed on properly. This is the lowest stakes problem it could indicate. If the light is still on after that, it is time to go to the auto shop. If the light is blinking, then it is time to drop everything and go to the auto shop now.

Engine Misfires and What They Mean

The second most common reason your check engine light is on is what is called a “misfire” inside the engine. This happens when there is either an abundance or a lack of oxygen in the engine.

Car engines are “combustion engines”, meaning they rely on a steady stream of tiny explosions to function. They need oxygen for that, but too much oxygen will cause an uncontrollable explosion, while too little will result in no explosion at all. In either case, it disrupts the flow of the engine, causing it to briefly stall.

This stalling can literally be one second or less. But if there is instability in the engine, a problem with the filter, or any number of other problems, then that misfire will not be an isolated incident. Misfires can happen somewhat randomly due to anomalies in the atmosphere, but they will usually be engine problems.

This is also the kind of thing that will cause your engine light to blink. This indicates that there is anything from a leak in the fuel line to an air bubble in the engine. None of these will cause the car to explode or anything so dramatic as that, but they are the kind of thing that needs to be addressed immediately.

So, be careful when you have a check engine light on. Listen to it, respect it, and keep yourself safe.