About Engine Coolant Temperature Sensors:

Coolant (with antifreeze) is an important part of keeping an engine at a safe temperature, and sustaining the optimum temperature of your engine. The coolant sensor constantly tells the engine car computer what the temperature of the coolant in the engine is. This gives an indication of how the operating temperature of the engine. Using this data, the car adjusts the engines electric radiator cooling fan speed, and also may adjust the fuel injection timing and fuel to air ratio in order to make your engine run smoother and cooler. Please note some cars also have an electronically controlled thermostat, which rely on the engine coolant sensor data sent to the engine computer to control when the engine temperature by controlling how open the engine thermostat is.

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Engine Coolant Temperature Sensor

How serious is a damaged engine coolant temperature sensor:

An engine coolant temperature sensor is an important component to stop your engine from overheating and damaging other components in your car. If you find that your coolant temperature sensor is damaged, it would be best to get your car checked immediately, to prevent further damage.



The most common fault code for engine coolant temperature sensors is P0118. This indicates a high voltage from the coolant temperature sensor and could indicate an overheating engine. Some causes of this fault code are:

– Faulty coolant temperature sensor: The most likely cause of this fault code is just a faulty coolant temperature sensor. The sensor may have corrosion, faulty wiring, or may not work at all. These would trigger this fault code.

– Bad Coolant: If your coolant is old or you haven’t had a service or cooling system flush and new anti freeze in a while, your coolant might be stale and not performing correctly. This means the coolant could have rust or corrosion and may not be cooling the engine properly. If this is the case, the coolant temperature sensor might be reading very high temperatures, and this fault code may appear.

Learn more about the fault code


Symptoms of a damaged coolant temperature sensor:

Check Engine Light

– Check Engine light: This will turn on if the car computer detects a engine coolant temperature sensor.

– Overheating engine: If your engine is overheating it could be a sign that your coolant temperature sensor is damaged as your radiator cooling fans may not be coming on while idling or in slow traffic. You can tell this by the temperature gauge on your dash board if your car is equipped, or there may be an overheating dash warning light.

– Rough idling: If your engine is idling roughly or even worse to drive, it could be because the coolant temperature sensor is damaged so the engine is not making the correct air fuel mixture, or timing ignitions properly.

– Poor fuel mileage: Fuel is expensive these days and a damaged coolant temperature sensor could be adding more cost to that bill. A damaged coolant temperature sensor could be responsible for a worse fuel efficiency and less mileage.

– Increased exhaust emissions: if the engine computer has an incorrect coolant temperature sensor reading there will be increased green house gas emissions from your cars exhaust pipe.



Engine coolant temperature sensor diagnostics and replacements in Hamilton:

At Grimmer Motors we offer a range of car diagnostics and repairs. We specialize in diagnostic vehicle scans and repairs and can get it right first time. Our reliable mechanics will be able to diagnose a faulty coolant temperature sensor and replace if required.

For all cooling system diagnostic checks or coolant temperature sensor replacements in Hamilton, contact Grimmer Motors today!


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