1999 deville coolant temperature

[MagicRat]

This is a long shot, but check to see if the thermostat was installed upside-down (aka. backwards). The description of the problem is quite consistent with a backwards t-stat.

[hingber]

changed all cooling system hoses when i got a new engine in 2004 or 25.000 miles ago.no loss of coolant for 5 days since i had caddy install new radiator and thermostat. will check hoses in a day or 2. drove a few miles tonight with outside temp at 76 and never got above 199F. will post in more detail tomorrow.

[hingber]

sorry for the delay in replying but i have spent most of the week with microsoft (india of course) trying to straighten out my email. microsoft deceided not to support outlook express on sept. 1st. i tried for about 10 hours to get it to work again with my MSN account. after 5 more hours on the phone i was finally told that outlook express will no longer sync with anything let alone MSN email. now back to the car. the car is still losing coolant as of sat sept 5th. i can see a small amount on the garage floor. i went to the caddy service on sat but due to the holiday they did not have any spare mechanics. i had gone 2 days before and just asked them to confirm that the water pump belt was working correctly. i will go back wed and have them check the hoses which i changed 5 years or 25000 miles ago.
the car is not overheating it is just not acting as before. at night on a flat street it will stay at 196-201F with the AC on or off. during the day it will(outside temp 75-85F) stay at 200F for long periods or stay at 215 -222F for long periods with no change in load such as speed or hills. this is with or without AC. i am sure the thermostat is in correctly because i had it changed when they installed the new radiator and the coolant temp is acting the same.
got peace of mind by turning off the digital temp indicator. i will wait for the coolant level warning before i panic.