Why is your 1993 grand marquis overheating and not showing on thermostat?

Your 1993 Grand Marquis may be overheating without the thermostat indicating a problem due to a faulty thermostat, a malfunctioning coolant temperature sensor, or low coolant levels. Additionally, a clogged radiator or a failing water pump could impede proper coolant circulation, causing overheating. It's essential to check for leaks, ensure the cooling system is filled with the correct coolant, and inspect for any obstructed hoses or components. If the issue persists, consider having a mechanic perform a thorough diagnostic.