Driving down the interstate and a 80 degree day so I flipped the AC on. AC is putting out cool air and then a couple minutes later my check gauges light comes on and my Temp is near 240 degrees. I flip the AC off and the temp drops fairly rapidly back to normal 210-215 degrees. The AC compressor does make a small chirping noise when clutch engages. Let me here your best guesses as to why this would happen all of a sudden when I didn't see anything more than 5-10 degree increase last year?