What is an engine oil temperature sensor (EOT)? What are the symptoms of a malfunctioning engine oil temperature sensor? What is an EOT sensor?
What is an Engine Oil Temperature Sensor?
Engines can be complex and require extensive testing to ensure they are working properly. How much air is the engine able to take? Is the fuel burning correctly? What is the noise level? All of these measurements require special equipment. Oil temperature is perhaps the most difficult to measure. Because oil has a specific operating range, it must be controlled. The engine won’t be properly lubricated if it gets too cold. Too hot oil can cause the viscosity to drop, which will again lead to engine damage. The oil temperature will change depending on how hard you run the engine. The measurement should be continuous.
The engine oil temperature sensor (EOT) is a component that monitors engine oil temperature and reports it to the powertrain control module. The oil temperature is critical for proper operation of the engine. The engine oil should only be a few degrees above the coolant. It usually has an optimum operating temperature of 85°C to 100°C. Because it is in constant contact with the internal components of the engine, it can exceed the coolant temperature by 10 – 20 °C. However, if the temperature of the oil is too high and rises to around 140-145°C, the oil will lose its properties and serious damage may occur to the engine.
The EOT sensor can be described as a type negative temperature coefficient (NTC thermistor). The temperature of the oil is an inversely proportional indicator of the internal resistance. The voltage signal is proportional to the temperature of the oil. It decreases as the temperature of the engine oil rises. It works by receiving a 5-volt reference signal (from the PCM) and sending a signal to it according to the oil’s temperature. This information is used by the PCM to determine fuel quality, timing of injection, and glow plug operation for diesel engines.
It may not be possible to install the EOT sensor on all vehicles. It is sometimes integrated into the oil level sensor on some vehicles. Some applications combine oil pressure and temperature sensors. Many performance cars also have an oil temperature gauge, which allows the driver to check the oil’s temperature.
What are the symptoms of a failed engine oil temperature sensor?
An engine can be damaged by a defective sensor in minutes. If the engine temperature is higher than 120 degrees but the sensor reads 80 to 90 degrees, the PCM will be informed that the engine should not cool down. This can lead to engine damage and overheating within minutes.
The oil temperature sensor can fail for many reasons. Most common causes of oil temperature sensor failure are damaged cables, connection problems, corrosion, rust, and a poor installation.
Here are some warning signs that your engine oil temperature sensor is about to stop working.
- – Illumination for check engine light
- – High or very low oil indicator
- – Immobility in the oil gauge
- – Engine overheating
- – Increased fuel consumption
- – The exhaust pipe is black with smoke
- – The engine can be extremely noisy
- – Cooling system problems
A malfunctioning cooling system can cause high oil temperatures. The coolant may not be reaching your engine properly if both the oil temperature gauge and engine temp gauge read high. This could be caused by a bad thermostat, radiator, and other components of your cooling system.
