Coolant Temperature Reading: What’s Normal and What’s not?

It is very important to keep an eye on the coolant temperature reading on your instrument cluster. Auto manufacturers install coolant temp sensors and temp gauges to help drivers track the engine and coolant temperature while driving.

As technology evolves in the automobile space, more features and computers are installed on newer cars. Some of these sensors are there to track temperature (we’ll get to it later on). Once the coolant temperature is high, one of these sensors will register a trouble code on the car computer.

These features have helped protect our vehicles from engine overheating by notifying the driver when something goes wrong.

In this article, we’ll discuss at length where your coolant temperature should be, how to fix high coolant temperature, and how the symptoms of a bad coolant temp sensor. Sit back and read the provided information.

What Should My Car Coolant Temperature Be?

coolant temperature gauge

Knowing exactly where your coolant temperature should be will keep you from a lot of hassles because engine overheating is far from inconvenient. Engine overheating can cause catastrophic damage to system components like cylinder head, engine block, radiator, head gasket, and other internal components. Hence, you should be watchful of the temp reading.

So, where should the coolant temperature be?

Normal coolant temperature varies from car to car. However, the normal engine temp should be in the range of 195 degrees to 220 degrees Fahrenheit. Though, most vehicles do not display the degrees of the coolant temp on the instrument cluster. They have markings that indicate low and high temperatures.

In this type of reading on the instrument cluster, if the temp gauge needle is resting on or close to the middle of the markings, it shows the temperature is normal. It takes the engine 1-2 minutes to get to normal operating temperature.

Do not think your coolant temperature is low when you start your car and the needle is close to the lowest point because it will start rising to its normal point as the engine warms up.

In some cars, the temp gauge will not get to the middle. What you should do is monitor where the needle rests when the engine is fully warmed. That way, you will notice on time when the needle starts creeping up, indicating a temp rise.

When you place a load on an engine, your temperature will typically go up. So, do not worry if you turn on the AC at full blast, or when towing and notice a rise in the temperature. It’s pretty normal.

In any case, if you suspect the rise is getting too much, pull out of the road and park in a safe place, switch off the AC, and turn off the engine. Consider opening your bonnet and allow the car to sit for 45 minutes to 1 hour. When the engine is cool, check your coolant level and top it with antifreeze if needed.

If you consistently notice temperature rise on your instrument cluster, inspect or consult a certified mechanic to thoroughly diagnose your vehicle. There are possible components that could be the underlying cause of the temperature rise. These components include; a lousy water pump, clogged thermostat, blown head gasket, low coolant level, bad radiator fan, or fan clutch.

Automakers are shifting from temperature gauges to temp warning lights. A blue light illuminates when you start your vehicle, indicating that the engine is below normal operating temperature. The blue light will disappear once the engine warms up.

All vehicles have a way of indicating how the temperature is running at every given time. Without it, you won’t know when your car is running low or high, resulting in severe damage to some system components.

If a yellow or red temp warning light glows on your instrument cluster, it indicates your car is overheating. Pull off the road, turn off your engine and inspect your cooling system components and check for leaks. If you don’t know the workings under the hood, consult your dealership or mechanic.

Note: whether you are asking for Prius’s normal coolant temperature, or any vehicle makes or model, the temp should be in the range of 195-220 degrees Fahrenheit.

coolant temperature high

What temp is too high for coolant?

Normal coolant temperature Celsius should be between 75 to 195 degrees. If your engine runs higher than this, consider inspecting your cooling system components. Prevention is better than cure, they say. You wouldn’t want to damage your engine parts which will result in an expensive fix because of ignorance or not inspecting your vehicle.

Why is my engine bay so hot?

If your temp gauge or temp warning light consistently shows your engine is overheating, or your engine bay is running so hot, you need to check your cooling system components immediately. Fix or replace any faulty components.

How do you fix high coolant temp?

  • If you notice a high coolant temperature while cruising on a sunny hot afternoon, do not panic. Instead, turn off the air conditioner to reduce the list on the engine. Then turn on the heater.
  • Don’t keep driving; find a safe place and pull over. Turn off the engine and allow it to cool for about 20-45 minutes. Call a friend or mechanic to tow your car.
  • Check things out. Inspect your cooling components and check the coolant level. If the coolant is low, top it with antifreeze( If you have any). This will help get your engine back to normal operating temperature.
  • If you did not start your car earlier, start it and inspect how the components are working. Gently drive your car to the nearest auto garage for thorough inspection and fixes.

Is engine temperature the same as coolant temperature?

The engine temperature is usually hotter than the coolant temperature, especially around the cylinders. However, engine and coolant temp is considered to be the same since the engine and coolant temperature are usually controlled by one sensor.

Coolant temperature sensors are usually found on the cylinder head, and mostly on the pipe that transports antifreeze from the radiator to the thermostat. This demonstrates that this sensor monitors both engine and coolant temp.

Why are the signs of a bad coolant temp sensor?

Like other cooling system components, a faulty coolant temp sensor will display some signs to notify the driver of a problem. These symptoms include;

  • Black smoke from the engine
  • Poor fuel economy
  • Temp warning light
  • Check engine light
  • Overheating engine.

Final Word

Ensuring your cooling system components are working optimally is key to keeping your engine temperature as it should. So, if you suspect your coolant temperature is running high, make sure your system is working properly by diagnosing your vehicle and fixing or replacing any damaged parts.

As I always advise, if you’re not a car enthusiast or a petrolhead who knows the working principles of the underhood components, seek professional advice to avoid causing injury to yourself. In case you choose to check your coolant level, allow the engine to cool down before opening the radiator cap. If you open it when it is still hot, it’ll splash hot water on your face.

Osuagwu Solomon

Osuagwu Solomon is a certified mechanic with over a decade of experience in the mechanic garage, and he has over five years of experience in the writing industry. He started writing automotive articles to share his garage experience with car enthusiasts and armature mechanics. If he is not in the garage fixing challenging mechanical problems, he is writing automotive repair guides, buyer’s guides, and car and tools comparisons.

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