To check the coolant level on a 2003 Cadillac CTS, first ensure the engine is cool to avoid burns. Open the hood and locate the coolant reservoir, which is typically a translucent plastic tank. Check the fluid level against the marked indicators on the side of the reservoir; it should be between the "MIN" and "MAX" lines. If the coolant is low, add the appropriate coolant mixture as specified in the owner's manual.
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.
In a 2003 Cadillac CTS, you should add antifreeze to the coolant reservoir, which is typically located near the front of the engine bay. Look for a translucent plastic tank with a cap labeled for coolant or antifreeze. Make sure to check the coolant level and add a 50/50 mix of antifreeze and water if it's low. Always ensure the engine is cool before opening the cap to avoid burns.
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.