In the coolant recovery tank
location of 2003 cadillac coolant temperature sensor
Check the coolant level. check the radiator fans.
That means the engine is running HOT. Need to check the coolant level and check for coolant leaks.
Check coolant level Could be a weak thermostat
It could be symptomatic of a larger problem. The coolant may not be circulating properly, or the indicator panel or car's computer could be developing trouble.
Check to see if your electric fan turns on. Else check coolant level and replace thermostat.
You can tell the oil cooler is bad in a Cadillac CTS 2003 when oil is in the coolant and the water turns into a white muddy substance
Most likely cause is low coolant. Check your antifreeze level.
take it to a dealer or a junk yard that does repairs
If the coolant level is correct there are at least two reasons. First one is the thermostat and second one is the temperature sensor. You have to check basically the coolant level, the thermostat and the temperature sensor.
That means the engine is overheating. Check in this ORDER. First check coolant level in radiator, if low then Find and FIX the LEAK and refill the system with COOLANT. Check engine FAN clutch, Thermostat, Radiator making sure it is NOT stoped up. You will find your problem in these AREA.