my "fill coolent idiot light" comes on once in a while... but my coolent is fine what do i need to replace. i know on some cars the sensors are in the overflow bottle but i havent had time to look..........

 

You have to check the level by looking into the radiator. Looking at the coolant level with the dipstick in the overflow tank is not an accurate check. If the coolant is up to the bottom of the radiator neck and the low coolant lite is on, you have a problem with the sensor. You can try cleaning it up or replacing it. The sensor is the little black box stuck on the top of the radiator on the passenger side.