My cooling fan races more than it used to. The coolant level appears to be fine. Could it be a faulty sensor and where is it located and is it something I can replace myself? The engine temp gauge reads in the mid range so the system isn’t overheating. Thanks.
Try a new radiator cap. If your present one is not holding as much pressure as it should, the system efficiency goes down. As the cap gets worse, you will start to see higher temperatures when going up hill or sustained high speed driving.