My 09 DTS II has been over heating but never running hot, the fan will come on and cool it off but today it reached hot, I didn't smell any coolant burning and there does not seem to be a coolant leak. Any ideas or known problem?
Also check the purg line to see if it is clog this is the line from the coolant tank to the water pump housing. To check is it easy when the car is cold disconnect the line from the tank star the car and coolant should come out of it if nothing come out disconnect it from thewater pump housing to see if coolant come out remeber you have to do thing with a cold motor
This morning it was down a liter of dexcool, I have a test drive booked for tomorrow and I have until Aug 23 before the powertrain warranty ends (phew). I will let you know if it is the water pump, gasket or hoses.