Im am selling my Mustang and just recently getting the low coolant dashboard reading off and on, mainly when the car is sitting on a hill when the engine is cold.Usually goes away after I get down the road a waysto a stop sign and shut off my car thenrestart it. My fluid always stay full, so I know it must be the sensor. Rather then spending 100 bucks to replace the whole coolant resevoirsensor capassembly, is there something I can do as an alternative, clean the sensor, flush the system, etc.Just need a temporary fix that is cheep sinceI am selling thecar.Thanks

 

Add some anti freeze to the resivor tank.