Why Check Engine Light Comes On In Hot Weather But Not In The Cold? (6 reasons)

why-does-my-check-engine-light-come-on-it-hot-weather-but-not-in-cold-weather

The check engine light is one of the most dreaded things for a driver. It can mean anything from a loose gas cap to a major engine problem. But why does it come on more often in hot weather? And why doesn’t it come on in cold weather? There are a few reasons for this, and we will discuss them in this article. Stay tuned to learn more about your car’s health!

Reasons why engine light comes on in hot weather

The check engine light on your dashboard is designed to let you know when something is wrong with your car’s engine. However, it can be triggered by a variety of things, including:

1. A loose gas cap

First and foremost a loose gas cap can cause your check engine light to come on. It is one of the most common reasons for the light to activate. The gas cap seals your car’s fuel system and helps keep fumes from escaping. If it is not tightened properly, or if it is damaged, it can cause your check engine light to come on.

A loose gas cap mostly happens when the temperature is extremely hot outside. The heat causes the gas to expand and escape from the loose gas cap. As a result, your check engine light will come on to alert you of the problem.

2. A faulty oxygen sensor

The oxygen sensor is used to measure the amount of unburnt oxygen in your car’s exhaust system. This sensor sends data to the computer system of your car and in turn, uses it to regulate the air to fuel mixture. If the oxygen sensor is not working properly, it can cause the check engine light to come on.

In hot weather, the oxygen sensors can be damaged by the heat, which can cause them to malfunction and trigger the check engine light.

A faulty oxygen sensor can also be caused by a variety of things, including:

  • A build-up of carbon on the sensor: This occurs in your car’s engine as a result of the combustion process. Over time, this build-up can cause the oxygen sensor to become less sensitive and eventually fail.
  • Exposure to lead: Lead exposure can damage the oxygen sensor and cause it to fail. Lead exposure is mainly caused by using leaded gasoline or by working with lead-based paint.
  • Exposure to oil: Oil exposure can also damage the oxygen sensor and cause it to fail. This is because oil can coat the sensor and prevent it from accurately measuring the amount of unburnt oxygen in the exhaust system.
  • A bad connection: But connection in the oxygen sensor occurs because of a bad connection in the wiring. This causes the sensor to get inaccurate readings and eventually fail.
  • Exhaust leaks: Finally, If there’s an exhaust leak, it can cause the oxygen sensor to malfunction. this can also happen if the oxygen sensor is damaged or if it’s not properly installed.

2. Excess heat from the engine

Another reason why your engine light might come on in hot weather is because of excessive heat. During the summer, the temperature under your car’s hood can get up to 100 degrees Fahrenheit or more. This heat can damage your car’s engine.

If you ever touched the hood of your car during the summer you know how hot it can get. The excessive heat from your engine can cause the spark plugs to wear out and eventually fail. It can also damage your catalyst convertor and most importantly oxygen sensor

3. An overheated catalytic converter

Another reason is an overheated catalytic converter. The catalytic converter is responsible for reducing emissions from your car’s exhaust system. It does this by converting harmful gases into less harmful ones.

If the catalytic converter is not working properly, it can cause the check engine light to come on. When the weather is hot the catalyst converter can overheat and cause the check engine light to come on.

Your catalytic converter can also go bad for a number of reasons, including:

  • Exhaust leaks: If there’s an exhaust leak, it can allow harmful gases to escape from the system before they’re converted. This can damage the catalytic converter and eventually cause it to fail.
  • Clogged filter: The catalytic converter has a filter that can become clogged with dirt and debris especially in hot weather when there is so much dust. This can prevent the converter from working properly and eventually cause it to fail.
  • Damage: Finally, the catalytic converter can be damaged by several things, including physical damage, heat damage, or chemical damage.

4. A faulty spark plug

The spark plugs are responsible for igniting the air/fuel mixture in your car’s engine. If they are not working properly, it can cause the engine to run lean (too much air and not enough fuel) or rich (too much fuel and not enough air).

Either way, this can trigger the check engine light. In hot weather, the spark plugs can expand and contract due to the heat, which can cause them to become damaged or dislodged.

5. A clogged air filter

The air filter is responsible for keeping your car’s engine clean by trapping dirt and debris. If it becomes clogged, it can restrict the flow of air to the engine and cause the check engine light to come on.

In hot weather, the air filter can get clogged more easily due to the increased amount of dust and pollen in the air, and also this is a huge problem if you live in an area with a lot of construction. This is because you come in contact with more dirt and debris, which can clog your air filter.

6. A dirty Mass Air Flow (MAF) sensor

The MAF sensor is responsible for measuring the amount of air flowing into the engine. If it becomes dirty, it can cause the check engine light to come on. In hot weather, the MAF sensor can get dirty more easily due to the increased amount of dust and pollen in the air.

All of these reasons can cause the check engine light to come on in hot weather. But why doesn’t it come on in cold weather? There are a few reasons for this as well.

Reasons why engine light does not come on in cold weather

  1. The oxygen sensor is less likely to malfunction in cold weather. This is because the oxygen sensor is designed to work best in warmer temperatures.
  2. Excess heat from the engine is not an issue in cold weather. This means that the spark plugs and catalytic converter are less likely to be damaged by heat because of the cold temperature
  3. A clogged air filter is not as much of a problem in cold weather because there is less dust and pollen in the air.
  4. A dirty MAF sensor is not as much of a problem in cold weather because there is also less dust and pollen in the air.

All of these reasons can cause the check engine light to come on in hot weather, but not in cold weather. If you’re having this problem, it’s best to take your car to a mechanic and have it checked out.

What to do if your engine light comes on when the weather is hot

The engine is one of the most important parts of your car, hence it. is very important that you take care of it and maintain it properly. There are a few things you can do to prevent the engine light from coming on in hot weather:

1. Check your car’s oil level regularly

The first thing I would suggest you do is to check your car’s oil level. If it’s low, top it off and see if that fixes the problem. If not, then you should change the oil. by doing so it will help your car’s engine to run smoothly and prevent the light from coming on.

2. Keep your car clean, both inside and out

It’s important to keep your car clean, both inside and out. By doing so, you will prevent dirt and debris from clogging up your air filter and causing the check engine light to come on.

3. Check your spark plugs and replace them if necessary

If you think your spark plugs may be the problem, you can check them and see if they need to be replaced. You should do this every few months to keep your car’s engine running smoothly.

4. Regular maintenance

The best way to prevent the check engine light from coming on is to give your car regular maintenance. You can do this by regularly checking the air filter and replacing it when necessary. You should also get your car’s engine cleaned professionally every few months. This way, they can catch any potential problems before they become big issues.

5. Check for leaks and repair them immediately

Finally, If there are any leaks in your car’s exhaust system, they need to be repaired as soon as possible. This will help to prevent harmful gasses from escaping before being converted and also prevent the check engine light from coming on.

If you take these preventive measures, you can avoid the engine light from coming on in hot weather. However, if it does come on, make sure to take your car to a mechanic as soon as possible to get it checked out.

Final thoughts

These are the reasons I think causes your engine light to come on in hot weather. By following these tips, you can prevent the check engine light from coming on. However, if it does come on, don’t panic. Just take your car to a mechanic and have it checked out. They’ll be able to diagnose the problem and get your car running smoothly again in no time.

Thanks for reading! I hope this was helpful. 🙂

Gideon Ansah Baffour

Hello, passionate reader My name is GIDEON BAFFOUR ANSAH. There are a lot of things in this world that I love. My family, my friends, dogs, video games, and of course – everything with engines. It has been a passion of mine for as long as I can remember. There is just something about them that makes me happy. I've been blazing up the trails and immersing myself in this wonderful hobby turned career and on this website, I'm excited each day to share everything I've learned and continue to learn a day in day out.

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