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Coolant Level Sensor Replacement Cost

Know what price you should pay to get your vehicle fixed.

The average cost for a Coolant Level Sensor Replacement is between $47 and $114. Labor costs are estimated between $26 and $67 while parts are priced between $21 and $47. Estimate does not include taxes and fees.
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What is an Engine Coolant Level Sensor?

During normal operation, an engine produces a lot of heat. The cooling system makes sure that the engine runs within a consistent temperature range without overheating. A mixture of coolant and water is circulated through the engine block to absorb excess heat. It is routed out of the engine and through the radiator, where its temperature drops before it enters the engine again. The coolant is moved through the system by the water pump, driven by a serpentine belt on the front of the engine. And the temperature is regulated with a thermostat placed in the path of the coolant. It is essential that the amount of coolant in the system be kept full. The engine coolant level sensor alerts the driver should the amount of coolant drop too low.

How do Engine Coolant Level Sensors work?

The coolant level sensor detects the amount of fluid in the cooling system. The sensor may be mounted in the radiator or in the coolant overflow bottle (also known as an expansion tank). The coolant level sensor works in concert with a float mechanism containing a magnet. As the fluid level rises and falls, the float raises and lowers - along with its magnet. The magnet affects the coolant level sensor, causing its metal terminals to make or break contact with one another. The resulting electrical signal is sent to an Electronic Control Module (ECM), which turns on a dashboard warning light to tell the driver that the coolant level is low. The ECM may also modify engine performance - effectively shutting down engine operation - should the coolant level drop too low.

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What are the symptoms of a bad Engine Coolant Level Sensor?

Symptoms of a bad coolant level sensor include a dashboard warning light that will not go out, or an engine that repeatedly overheats. If the sensor is not functioning and the engine coolant level drops, the engine can overheat with no warning. This can cause significant damage to the engine.

Can I drive with a bad Engine Coolant Level Sensor?

If the engine on a car, truck, or SUV overheats, the vehicle should be pulled over immediately and should be towed to a trusted repair facility. In some cases, the ECM will force the engine into emergency "limp" mode, effectively idling the engine so that the vehicle cannot be driven fast or far. Eventually the ECM will shut down the vehicle completely. But if the coolant level sensor is not sending a signal to the ECM, the engine can overheat with no warning, and the ECM will not know to initiate safety measures. If a vehicle shows signs of overheating - a temperature light on the dash, high temperature gauge reading, steam coming out from under the hood - do not attempt to continue driving the vehicle. Otherwise, significant engine damage can occur.

How often do Engine Coolant Level Sensors need replacement?

The engine coolant level sensor should last the lifetime of the vehicle. But it is not uncommon for a sensor to fail. In fact, it is fairly common. Still, there is no regular replacement interval scheduled. Ensuring proper maintenance of the cooling system may help prevent premature failure due to corrosive buildup on the sensor.

How are Engine Coolant Level Sensor issues diagnosed?

With the engine cool, a technician will check for a faulty coolant level sensor by removing the radiator cap and checking the fluid level. If the level is low, but the dashboard warning lamp is not lit, the sensor is likely to be at fault. A low fluid level is not caused by a bad sensor. It simply is not detected when the sensor is bad. So, if the engine is overheating, but no warning light comes on, the sensor is indicated. If the warning lamp is lit, but will not go out, the technician will use a scan tool to check for a diagnostic trouble code that might reveal a bad sensor. A multimeter may also be used to test the sensor circuit.

How are Engine Coolant Level Sensors replaced?

With the engine cool, a technician will disable power to the coolant level sensor by pulling a fuse or disconnecting the battery before unplugging the sensor from the wiring harness. On some vehicles, the sensor is removed by simply twisting and pulling it from its mounting location. On other vehicles, the sensor may be attached with clips or bolts. Many sensors can be removed without any loss of fluid, but when some sensors are removed, fluid will leak out and need to be replaced and the air bled from the system before the repair is complete.

RepairPal Recommendations for Engine Coolant Level Sensor issues

RepairPal recommends that the cooling system be thoroughly inspected by a qualified technician at a trusted repair facility as soon as possible when signs of overheating appear. Also, ensure that the cooling system is properly maintained to help avoid this, and other possible complications.

What to look out for when dealing with Engine Coolant Level Sensor issues

An engine in a late model vehicle is designed to run somewhere between 195 and 220 degrees. But the fluid in the cooling system can rise well in excess of 220 degrees when the engine overheats. This produces steam that will cause severe injury from scalding if the system is opened when hot and under pressure. Burns are possible as the engine components are also at a high temperature. Extreme caution should be exercised when working on a hot engine, especially one that is overheated. If steam is seen coming from under the hood, the engine should be allowed to cool for at least a half hour before the hood is opened, and the radiator cap should not be removed until the engine is cool enough to touch with a bare hand.

Can I replace the Engine Coolant Level Sensor myself?

The cooling system is typically serviceable by the DIY mechanic, however, following guidelines for properly bleeding the engine coolant system of air is mandatory to prevent overheating and damage to the engine. If the sensor has failed without any other issues to the cooling system, it can be replaced easily by nearly anyone who follows proper safety procedures as mentioned.

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