the other day i replaced the thermostat on a 1996 deville and when running it on the high way it runs about 194 but when you get off the high way it runs up to 215 and is over flowing can any one tell me what temp these cars are suposed to run at and when the fans are suposed to kick on and what the LBS for the radiator cap should be thanks alot

Hi!! I am having the same problem with my 98 Deville. It always runs around 215- up to 221. On the forum I've been told that the car should run 180, my mechanic told me the car is running where it should be now, and that 180 is way too cold. I still think 221 is way too hot, but car never has a problem. The mechanic also told me that the fan isn't supposed to come on until 227. That's all I've been able to find out. Also, guy at Autozone also thought 215-221 way too hot. Actually I keep meaning to call Cadillac and ask them directly, but then I forget. If I ever get around to that I'll let you know what they say, and if you hear any more please let me know!! Good Luck!!

normal is around 195-210 check be sure you don't have any leaks and then you probably have blown head gaskets....common problem