Can Hot Weather Cause Check Engine Light to Come On, thermometer and sun image

Can Hot Weather Cause Check Engine Light to Come On

When summer came, I experienced illumination from both the bright sun and the check engine light. Then I questioned myself: can hot weather cause check engine light to come on?

Hot weather can cause the check engine light to come on due to various factors. Weak battery issues, broken vehicle AC, a broken serpentine belt, an overheating engine, engine oil thinning, clutch wear and tear, cooling system problems, and battery strain can all contribute to the check engine light’s activation.

I did thorough research to find out the connection between hot weather and the check engine light. In this article, I will explain common reasons for the check engine light to illuminate during the summer months and how to fix them.

Reasons For Check Engine Light in Hot Weather

Weak Battery IssuesBattery strain in hot weather Terminals become loose Increased electrical loadCheck for corrosion
Secure battery mount
Carry jumper cables
Broken Vehicle ACFluid level issues Electrical malfunctionCheck fluid levels
Inspect the battery and electrical functions
Check refrigeration fluid
Overheating EngineLow coolant levels Oil leaks Blocked hoses Radiator issuesMaintain appropriate coolant levels Inspect for leaks and blockages
Check the radiator and water pump
Engine Oil IssueThinning oil at high temperaturesConsider using oil suitable for higher temperatures
Regularly check and change the oil
Clutch Wear and TearIncreased pressure on the clutch during Summer drivingDon’t ride with the clutch pressed
Sit in neutral when stopped
Use the handbrake while parking Change gear quickly
Broken Serpentine BeltWorn-out beltHave an expert inspect and replace the belt if necessary
Cooling SystemOverworked system due to extreme temperaturesEnsure proper coolant levels Regularly replace coolant fluid

Let’s discuss causes and solutions separately.

Battery Issues

The hot summer weather puts additional strain on your vehicle’s battery. This shortens its lifespan and reduces efficiency.


  1. Check for any visible corrosion or damaged plastic pieces on the battery.
  2. Ensure the battery is securely mounted to reduce vibration.
  3. Carrying jumper cables is always a good idea.
  4. If your battery is more than 3-5 years old, consider replacing it to avoid potential damage to the alternator and other costly repairs.

Vehicle AC Problems

car AC hole

Driving without a properly functioning air conditioning system during the scorching summer months can be uncomfortable.


  1. To prevent AC issues, ensure the fluid levels are adequate, and the battery is in good working order.
  2. Check the refrigeration fluid if the air conditioner fails to blow cold air.
  3. If you notice any abnormalities in your electrical functions, have an expert inspect the system.

Overheating Engine

Summer temperatures place a significant strain on your vehicle’s engine. Ensure that coolant levels are appropriate and regularly top them off.


  1. Check for blocked hoses, corrosion, mineral deposits, radiator issues, and a broken water pump.
  2. Inspect the engine for leaks.
  3. If the engine begins to overheat, pull over and let it cool down.

Note: Continued driving with an overheated engine can cause severe damage. Don’t let it become as hot as fire.

Engine Oil

Hot weather causes engine oil to thin, leading to increased friction and potential damage to engine components.


  1. Consider using an oil grade suitable for higher temperatures.
  2. Check your oil regularly and change it at the recommended intervals.

Tip: Consult your vehicle’s handbook for specific recommendations.

Clutch Wear and Tear

High temperatures in the summer months can lead to clutch wear and tear. Watch out for warning signs like a high clutch bite or a heavy clutch pedal.


  1. Don’t ride with the clutch pressed
  2. Sit in neutral when stopped
  3. Use the handbrake while parking
  4. Change gear quickly

Broken Serpentine Belt

Serpentine belt

The serpentine belt drives various engine components, including the AC, power steering, and alternator. In hot weather, this belt wears out faster. This leads to a complete failure of these systems.


  1. Regular maintenance is essential to avoid unexpected breakdowns.
  2. To prevent this, you have to get the belt inspected before summer comes.

Cooling System

Your vehicle’s cooling system works harder during extreme weather conditions. To keep the engine at the right temperature, ensure the coolant levels are sufficient. Over time, coolant can break down and accumulate contaminants. This affects the radiator’s performance.


  1. Regularly inspect the coolant levels
  2. Replace the fluid as needed

All the above issues you face in hot weather result in a check engine light.

Other Minor Problems Cause Check Engine Light in Hot Weather

Other than the problems mentioned above, here are some minor things that may cause the check engine light in cold weather.

Faulty Oxygen Sensor

The oxygen sensor’s duty is to regulate the fuel-to-air ratio in the engine. If it becomes faulty, it may provide incorrect readings. This leads to improper fuel combustion and increased emissions. This triggers the check engine light.

Loose Gas Caps

In hot weather, the air inside the gas tank can expand, increasing pressure. If the gas cap is loose or not properly sealed, it can allow fuel vapors to escape and disrupt the pressure balance in the fuel system.

Faulty Spark Plugs

Spark plugs are responsible for initiating the combustion process within the engine cylinders. In hot weather, if the spark plugs are worn out, covered in carbon deposits, or not functioning properly, it leads to misfires or inefficient combustion. The check engine light comes on when there is a fault in the spark plugs.

Malfunctioning Catalytic Converter

The catalytic converter plays a crucial role in transforming harmful gases into less harmful ones within a vehicle’s exhaust system. Under normal operating conditions, it efficiently converts these toxic emissions.

However, elevated temperatures, particularly during hot weather conditions, can impose excessive heat stress on the catalytic converter. This potentially leads to overheating or damage.


How can I tell if the check engine light on my car is serious?

The check engine light may flash or stay on continuously, depending on the problem. Something needs to be corrected immediately away when a light is blinking or, in some cars, when a red light appears in place of a yellow or orange light.

Why does my car run OK even though my check engine light is on?

These issues can include problems with the engine, the electrical system, the fluid levels, or the car’s emissions system. Even something as easy as forgetting to tighten your gas cap might cause a problem; in fact, this is the most frequent cause of check engine lights in the first place.

Are car sensors susceptible to heat?

More humidity in the air and warmer temperatures can have an impact on a variety of factors, including failed sensors and reduced fuel efficiency.

Can dust cause the check engine light?

The electronic control unit in your car receives crucial information from the oxygen sensor, often known as an O2 sensor. The check engine light may come on if a sensor sends the wrong data to the ECU due to failure or contamination with oil, dust, debris, or rust. 


Again, “Can hot weather cause check engine light to come on?” Yes, it is. Keeping an eye on your vehicle’s check engine light during the summer months is crucial for maintaining its performance and avoiding costly repairs.

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