Cooling System Problems:
* Low Coolant Level: This is the most common and often easiest to fix. Check the coolant reservoir and add coolant if necessary. A leak somewhere in the system is the underlying problem if the level keeps dropping.
* Coolant Leaks: Inspect hoses, radiator, water pump, thermostat housing, and heater core for leaks. Look for wet spots, corrosion, or signs of dripping. Pressure testing the cooling system is often necessary to find small leaks.
* Clogged Radiator: A radiator choked with debris (like bugs, leaves, or rust) restricts coolant flow, leading to overheating. Flushing the radiator is often the solution.
* Faulty Water Pump: The water pump circulates coolant. A failing pump won't circulate coolant effectively, causing overheating. Listen for unusual noises (whining or grinding) from the pump area.
* Bad Thermostat: A stuck closed thermostat prevents coolant from circulating until the engine reaches extremely high temperatures, then suddenly opens causing a large temperature swing. A stuck open thermostat will prevent the engine from reaching optimal operating temperature.
* Faulty Radiator Fan: The radiator fan helps cool the coolant. If it's not working (or the fan clutch is failing), the engine will overheat, especially at idle or low speeds. Check the fan operation; it should come on when the engine gets hot.
* Clogged Radiator Cap: A faulty radiator cap can prevent proper pressure buildup in the cooling system, reducing its efficiency.
* Air in the Cooling System: Air pockets can impede coolant flow. Properly bleeding the cooling system is necessary to remove air.
Engine Problems (Less Common but More Serious):
* Head Gasket Failure: A blown head gasket allows coolant to leak into the engine cylinders or oil, causing overheating and potentially white smoke from the exhaust. This is a major repair.
* Cracked Engine Block or Cylinder Head: A crack allows coolant to leak, leading to overheating. This is usually a catastrophic failure and requires significant repair.
* Low Engine Oil: Low oil pressure can lead to overheating as the oil is crucial for lubrication and heat dissipation. Check your oil level.
Other Possibilities:
* Faulty Temperature Sensor: An inaccurate temperature sensor can give a false reading, leading you to believe the engine is overheating when it's not (or vice versa).
* Incorrect Coolant Mixture: Using the wrong coolant mixture (too much water, not enough antifreeze) can affect the boiling point and cooling efficiency.
Troubleshooting Steps:
1. Check the coolant level: This is the first and easiest thing to do.
2. Visually inspect the cooling system: Look for leaks.
3. Feel the radiator hoses: Are they hot? If not, the thermostat might be stuck closed.
4. Check the radiator fan operation: Does it come on when the engine is hot?
5. If you're comfortable, feel the temperature of the engine block. (Caution: Hot engine parts can cause serious burns!)
If you're not comfortable diagnosing and repairing these issues yourself, take your 1998 Chrysler Concorde to a qualified mechanic. Overheating can cause serious engine damage if not addressed promptly.
