Coolant Level Sensor Replacement Cost Estimate

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.

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 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.

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.