Make sure your radiator cap is on right if you put it on upside down it doesn't feel right and you start losing antifreeze also change your antifreeze put the green antifreeze in your car because the orange antifreeze heats the gaskets away make sure your radiator cap is not cracked on the plastic or rubber part if that is not the problem your water pump may not be pumping check your vehicle when it's hot and see if the thermostat kicks open when you turn on the heater if the hose has pressure your thermostat is stuck..Hey guys, I have a 2011 Cadillac CTS 3.0. I was headed into town which is about a 15-20 min drive one way and once I was headed home I noticed I was hearing a humming noise coming from the engine compartment. All of a sudden I got a ding alert from the gauge dashboard then it had an alert message show up saying: engine overheating Turn off AC. And to mention that at the time when it did this my ac was off. After the message alert the temp gauge shot up in a matter of seconds from a notch below the halfway point to all the way past red. As soon as this happened I pulled into a parking lot and after shooting up to red it only stayed there for about five seconds then shot back down to normal temp. I parked and opened up the hood and could smell coolant but could not locate any leaks and for the other ten minute drive back home never shot back up again. So my question is has anyone else known or experienced this issue? I’ve heard it could be one of the fans or the water pump?