Cadillac Repair: 1999 CADILLAC FLEETWOOD LIMITED, cadillac fleetwood, engine coolant temperature

Question
Dear Bill:

I have several questions. First of all, I own a 1999 Fleetwood Limited. It seems as though only a few thousand of these were made.  What is the difference between this model and the Deville?  Also, I just recently experienced some small antifreeze leakage.  The Cadillac dealer replaced the water pump and a radiator place replaced the seals on the radiator.  Although I am no longer leaking antifreeze, I have been monitoring my coolant temperature on my dashboard and my engine temperature seems to run higher than it had been (239-257 degrees).  What is a normal engine coolant temperature for this type of car.  Note:  Although it only happened once, when the coolant temperature reached 257 degrees, my dashboard indicated "engine hot, A/C off".  Could my head gaskets be going bad?

Answer
Hi Darryl, As the name says limited means a special run of cars was produced and it could be in just one area of the country that gets those cars. Normally a Fleetwood will have more power options as standard over the Deville. Maybe the seat heater will be standard equipment in the Fleetwood where as it is an option in the Deville for example. The temp range should be between 208 and 220. Maybe the radiator has a restriction internally or the thermostat chose this time to open later. I would start with replacing the thermostat and make sure the coolant is up in the resivior and then see what the temp is. If it is still higher then I would go back to the dealer and have them recheck their work and possibly have the radiator taken out and flow tested at a radiator shop or have them install a differant one under warrenty. At this point I do not feel that the head gaskets are an issue but if they find nothing wrong with the water pump, radiator or thermostat then it could be a problem. When the dash indicated "engine hot, A/C off" that is a safety deactivation so that the A/C isn't causeing excess heat to be built up in the engine or radiator. At that point turning your cliamate control to 90 and hi fan would help cool things off also instead of having to sit at the side of the road with the engine off waiting for things to cool. The Northstar System has a unique feature in that so long as the vehicle is moving the computor will turn off the fuel injectors to cylinders in pairs to help cool things off and will turn off up to 4 cylinders at a time and then change the cylinders so that they only pump air to help cool the engine. Hope that helps. Bill