family auto mechanics - helping you find the problem

family auto mechanics - helping you find the problem

Bad Coolant Sensor? Find Out The Signs & How To Fix The Problem

by Herman Mills

The coolant sensor helps your car determine the temperature within the engine. This temperature is easily transmitted to you and could help you avoid damage from overheating. But the sensor can fail, and you should know the signs associated with a bad sensor and how to take care of it.

Signs Of A Bad Coolant Sensor

Look out for the following:

  • A bad coolant sensor may make your car work harder than it needs to. This happens because your car may begin to overheat often, so you may notice excessive fuel consumption.
  • The car may not know how much gasoline your engine needs, so it will pump excess amounts of gasoline. This rich fuel mixture will produce black smoke from your exhaust pipe.
  • You may notice problems starting your car when it finally reaches normal operating temperature. This is due to your car's inability to read the temperature and regulate the fuel-to-air mixture.

Talk to your auto care specialist to help confirm your suspicions. If the problem is your coolant sensor, you can try the following.

Replacing Your Own Coolant Sensor

You will need the following:

  • A new coolant temperature sensor that fits your car specifically
  • Your socket and wrench set
  • A container to drain coolant.
  • New coolant
  • Protective glasses and gloves
  • Your repair manual


  1. Park the vehicle in a safe and leveled place.
  2. Make sure the engine is cool.
  3. Put your glasses and gloves on for your safety.
  4. Disconnect the car battery, just to be cautious.
  5. Locate your radiator's drain valve. Place the container under your car, directly under the valve, and open it. Let the coolant drain. You can use your repair manual to find the drain valve.
  6. Look for the coolant temperature sensor, which is usually on the side of your engine. You can use your owner's repair manual to find it.
  7. Unscrew the coolant temperature sensor using your wrench and socket set.
  8. Screw in your new coolant temperature sensor. Be careful not to screw the coolant temperature sensor too tightly. 
  9. Add coolant to your vehicle.
  10. Reconnect the power cables to your battery, and you are done.

Hopefully this solves the problem. And remember that you can have your auto care specialist (from Oak Hollow Tire Car Care Center Inc or another company) replace your sensor if you do not feel comfortable with these steps. The issue may be due to other issues, like a clogged fuel filter or a bad catalytic converter, if the problem still exists. 


About Me

family auto mechanics - helping you find the problem

As the son and grandson of mechanics, I spent much of my child hood under the hood of many cars. I have listened and learned about so many different problems and how to repair them effectively. I created this blog to cover as many car problems as possible without overwhelming readers. You will find tips for troubleshooting, advice for when to take it to a professional and suggestions for when to stop driving the car or truck immediately to prevent further and more costly damage. We hope that you find all of this information helpful and useful, allowing you to have a great running car.