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How Can You Tell If Your Engine Coolant Temperature Sensor Is Bad?

How Can You Tell If Your Engine Coolant Temperature Sensor Is Bad?

The coolant temperature sensor is a key part of your vehicle’s optimal performance, ensuring the car runs safely and securely. While you operate and drive your car, the engine goes through continuous engine combustion. Continuous combustion can make it overheat and potentially gain too much friction while driving, especially during warm temperatures and the day time. If the sensor overheats, this is an easy way to answer, “how can you tell if your engine coolant temperature sensor is bad?”


 

The engine coolant temperature sensor can determine if the coolant is working properly in your car, using different fluids and liquids through the engine. You might also know that overheating can affect engine performance and cause the engine to break down over time. The water is passed through the pipes to maintain temperature and keep the pipes cool, showing your engine coolant temperature sensor’s importance.

 

However, suppose the engine coolant temperature sensor cannot remain cool while performing the necessary duties. In that case, it can help you answer, “how can you tell if your engine coolant temperature sensor is bad?”

Engine Coolant Temperature Sensor

 

As we know, the coolant temperature sensor, which is also known commonly as the coolant temperature switch, is a key part of the engine system. This sensor can help analyze and manage the engine system by monitoring the engine’s coolant temperature. The coolant is a liquid mixed with water to keep the radiator from freezing or overheating in extreme weather conditions or conditions within your engine. 

 

Also known as antifreeze, coolant comes in many different kinds of types for various types of engines and cars. It is important to know what specific coolant variety is correct for your car to get the right variety. Getting the wrong kind of coolant can help you answer, “how can you tell if your engine coolant temperature sensor is bad?”

  • Engine Coolant Temperature Sensor Function

Once the engine coolant temperature sensor measures the coolant temperature in the engine, the next step is that the coolant temperature sensor operates using electrical resistance to determine the precise temperature. This signal taken by the engine coolant temperature sensor is then sent to the car’s computer so the proper changes can be made to the engine’s timing and fuel calculations for optimal performance. If the engine timing is incorrect, this can answer, “how can you tell if your engine coolant temperature sensor is bad?”

  • Engine Coolant Temperature Sensor Computer

If the computer and the engine are not working right and determining the engine coolant temperature, then this can be a way that you can tell if your engine coolant temperature sensor is bad. The car’s computer is also in charge of turning back the engine performance settings if it detects that the engine temperature is too high and can cause overheating. 

 

Reducing the engine performance is done to prevent any further damage to the engine that can occur from excessive friction and heat within the engine system. If there is excessive heat within the engine, it can answer, “how can you tell if your engine coolant temperature sensor is bad?”

  • Engine Coolant Temperature Sensor Location

Usually, the location of the coolant temperature sensor is directly behind the coolant pipe. In most modern cars and vehicles, this is present behind the right cylinder head located right underneath the air intake pipe. 

 

Different kinds of cars and manufacturers, dependent on the make, model, and year of the car, have different ways of placing the coolant temperature sensor that differs depending on the car design. Finding the engine coolant temperature sensor can help you answer the question of “how can you tell if your engine coolant temperature sensor is bad?”

 

Some vehicles contain more than one temperature coolant sensor. These different engine coolant temperature sensors sometimes send signals to the dashboard and the engine control unit within the engine system. The use of multiple engine coolant temperature sensors is optional, with only one coolant sensor necessary to send signals to both of the desired receivers. 

Steps of the Engine Coolant Temperature Sensor

  • Reading Engine Functions

The engine coolant temperature sensor works by reading the engine functions. The ECT sensor is located near the engine thermostat, which calculates the temperature within the engine. The engine coolant temperature sensor measures the temperature provided by the thermostat and the coolant. If the engine coolant temperature sensor does not correctly read the engine functions, this can answer, “how can you tell if your engine coolant temperature sensor is bad?”

  • Records Engine Temperature

The engine’s recorded temperature transfers to the ECU, which adjusts the engine functions accordingly. If you can tell that your engine coolant temperature sensor is bad, you will notice your engine overheating. Engine overheating helps determine “how can you tell if your engine coolant temperature sensor is bad?”

  • Adjusting the Cooling Fan

The onboard computer also functions by opening and shutting down the cooling fan depending on the temperature reading and the controls. This computer determines the exhaust gas recirculation and the fuel combustion process. 

Faulty Coolant Temperature Sensor Symptoms

  • Overheating Engine

A sign that the coolant temperature sensor is not working correctly, and the coolant temperature sensor is bad is an overheating engine. Although the engine overheating can be due to various seasons a poor coolant temperature sensor is a root cause. Along with this reason, the other causes of engine overheating and excessive friction is too little coolant, cooling system leaks, broken water pump, radiator issues, the oil being too low, thermostat failure, issues with hoses and belts, and the heater core congested. 

 

The coolant temperature sensor can also fail because it causes the car to send a consistently hit signal to the car. This can cause the car’s computer to incorrectly compensate for a lean fuel mixture, resulting in consistent overheating, engine misfiring, or engine knocking. These loud noises and the overheating engine can help answer, “how can you tell if your engine coolant temperature sensor is bad?”

  • Reduced Fuel Economy

One of the first symptoms that are widely noticeable is a poor fuel economy and reduced gas mileage. If the coolant temperature sensor goes bad and becomes damaged over time, this can lead to the wrong signals being transmitted to your car's computer. The coolant temperature sensor will not be able to do the correct fuel and timing calculations necessary for proper fuel economy. 

 

Furthermore, it is not uncommon for the coolant temperature sensor to fail and be damaged, sending a permanent signal to the computer. The permanent signal can cause the computer to consistently read that the engine is cold and result in higher fuel usage even when it is not necessary. A reduced fuel economy is a clear way to answer, “how can you tell if your engine coolant temperature sensor is bad?”

  • Black Smoke from the Engine

Black smoke pouring out of the exhaust pipe is a sure way to see something wrong with your engine’s cooling system. If you are trying to answer, “how can you tell if your engine coolant temperature sensor is bad?” this dark smoke is an easy way to tell something that needs to be fixed as soon as possible. 

 

If the fuel mixture in your vehicle is too rich to the point where the fuel can’t be burned properly in the combustion chamber, this can lead to the fuel being burned in the exhaust pipes and causing black smoke to emit from the exhaust pipes. In the worst cases regarding your engine’s coolant system, the black smoke could mean you can no longer safely drive your car. 

 

Faulty readings from the coolant temperature sensor can cause your car’s engine to miscalculate the fuel to air mixture within the engine. When the air to fuel ratio for the mixture of the engine is not in the correct proportion, and if the fuel mixture is too lean or too rich, the fuel will not be able to burn within the combustion chamber properly. 

  • Check Engine Light

Another symptom that is easy to see in your car from either the driver or the passengers is that the illuminated check engine light will appear on your dash, showing how you can tell if your engine coolant temperature sensor is bad. For some types of cars, depending on the make, model, and year, the computer can turn off a Check Engine Light if it notices an issue with the sensor’s signal or circuit. The check engine light will stay on until the problem is fixed.

  • Rough Engine Idling

Due to a faulty engine coolant temperature sensor, the fuel mixture will adjust according to the senor’s calculations. The adjusted fuel mixture can cause the engine to vibrate uncontrollably or shake when the car is idling at a low speed or driving slowly. Consistent shaking can lead to other power losses within the car, and strange behaviors, like loud noises and thinking coming from beneath the hood. These loud noises and shaking movements can help answer the question of “how can you tell if your engine coolant temperature sensor is bad?”

Coolant Temperature Sensor Replacement Cost

 

The coolant temperature sensor’s average replacement cost is between $100 and $220, with the labor cost averaging around $40 and $140, while the parts itself usually run you about $50 to $80. The coolant temperature sensor is not as expensive compared to other key components of your car’s engine system and other installed sensors in your vehicle. The average cost for the engine coolant temperature sensor replacement is between $123 and $165, depending on the kind of vehicle you own. 

Average Cost of Parts

The average cost for most vehicles of the coolant temperature sensor replacement cost for parts ranges between $55 and $80. However, the lower end of the coolant temperature sensor price can go as little as $35, while the high end of the coolant temperature sensor parts price is around $90.

Cost Comparison

When comparing how much you might spend on the coolant temperature sensor replacement, we have listed your local mechanic prices, various chain stores, and parts-only stores. 

 

If you are getting the replacement at your local mechanic, this procedure will run between $89 and $272, depending on the type of car you have. The total price of the engine coolant temperature sensor replacement at chain stores will typically range between $87 and $299 depending on the make, model, and year of your vehicle. The least expensive choice for chain stores is NAPA, ranging between $79 and $289.

 

If you decide to do this repair on your own, Walmart sells parts averaging between $25 and $89, while Amazon ranges between $33 and $96 for the parts for this replacement. Figuring out if you need a replacement can help you determine the answer to “how can you tell if your engine coolant temperature sensor is bad?”

Sample Replacement Costs

Regarding popular vehicles on the market, we have included sample coolant temperature sensor costs to have an idea of how much you might spend. This cost comparison is useful when asking yourself, “how can you tell if your engine coolant temperature sensor is bad?”

 

The least expensive option is the Honda CR-V, costing only between $80 and $123 on average for the labor and parts in the car. The next least expensive option is the Honda Civic and Honda Accord, both averaging between $108 and $141 for the replacement’s total price.

 

The most expensive options for engine coolant temperature sensor replacement costs are the Toyota cars – the Corolla and the Camry. Both of these vehicles range between $179 and $272 for the total price. 

Conclusion

 

When asking yourself, “how can you tell if your engine coolant temperature sensor is bad?”, you need to know the function of this part in your car, the signs and symptoms of a faulty engine coolant temperature sensor, and the average replacement price.