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What is an Engine Coolant Sensor?

Updated: Apr 28, 2021

An engine coolant sensor measures the temperature of the engine’s coolant and it attached to your engine’s cylinder head.

Why is this sensor important and why does coolant temperature matter? Let’s learn more about this important automotive feature!

The engine coolant temperature sensor, or ECT, is an engine management system sensor used to monitor your engine’s coolant temperature. Your vehicle’s engine requires more fuel when it is cold, and less fuel when warmed up. Your car’s computer being aware of the coolant temperature of the engine helps it to know when to scale back engine performance settings if the engine becomes too hot, which prevents your car from overheating.

Temperature is very important to proper engine function, which is why the sensor’s proper functioning is essential to a healthy vehicle. Any problems with the engine coolant sensor can easily translate into larger engine performance problems.

How Do I Know my Sensor is Bad?

There are a few common symptoms and signs that can alert you of a bad coolant sensor:

Engine Overheating

There is a gauge on your car’s dashboard that shows you the engine’s temperature. If you see the needle on the “hot” side, rather than in the middle between hot and cold, your engine is likely overheating.

Bad Fuel Economy

When your coolant temperature sensor goes bad, it can send a false signal to the car’s computer and throw off the fuel calculations. The computer will think that the engine is cold when it really isn’t and therefore will use more fuel than is necessary, which reduces fuel economy.

Black Smoke

If you see black smoke coming from your car’s exhaust, the problem could be with your engine coolant sensor. The sensor sends the false cold signal to the computer causing it to over-enrich the fuel mixture. This makes it difficult for the fuel to be burned properly in the combustion chamber, resulting in black smoke that exits your vehicle through the exhaust pipes.

Check Engine Light is On

Your coolant temperature sensor is a part of your engine, so it makes sense that your car’s computer will notify you to check the engine when the sensor goes bad. However, the check engine light can come on for a number of different reasons and doesn’t always mean the issue is with the coolant sensor.

If your check engine light comes on, or you notice another symptom of engine or vehicle malfunction, get your car to a trustworthy repair shop as soon as possible. Getting the problem diagnosed and fixed by a professional ensures you’ll be back on the road safely in no time.

Looking for reliable Maryland engine repair service? Contact the professionals at Hillmuth Auto Care today!

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