* Leak: The most common cause. Coolant can leak from various places including:
* Radiator: Cracks, leaks in the hoses connected to it, or a failing radiator cap.
* Water pump: A failing water pump can leak coolant internally or externally.
* Hoses: Cracks, deterioration, or loose clamps.
* Engine block: Cracks in the engine block itself (a very serious problem).
* Heater core: Leaks inside the cabin can lead to a sweet smell and damp carpets.
* Thermostat housing: Cracks or a faulty gasket.
* Head Gasket Failure: A blown head gasket can allow coolant to leak into the engine oil (creating a milky substance in the oil) or into the combustion chamber (causing white smoke from the exhaust). This is a major repair.
* Internal Leak: Coolant could be leaking internally within the engine, perhaps into a cylinder. This often leads to overheating and other problems.
* Incorrect Reservoir Reading: Though less likely, there's a chance the coolant level sensor in the reservoir is faulty. This is less common than a leak.
What to do:
1. Don't just add coolant: Adding coolant without finding the leak is a temporary fix and could mask a serious problem leading to engine damage.
2. Check for leaks: Carefully inspect all hoses, the radiator, the water pump, and the engine block for any signs of coolant leaks. Look for wet spots, corrosion, or white residue (indicating coolant).
3. Check the engine oil: If the oil is milky or has a brown, mayonnaise-like substance, it strongly suggests a head gasket leak. This requires immediate attention.
4. Check the exhaust: White smoke from the exhaust can also indicate a head gasket or other serious internal leak.
5. Pressure test the cooling system: A mechanic can perform a pressure test to pinpoint leaks that might not be readily visible. This is the most reliable way to diagnose the problem.
6. Consult a mechanic: If you're not comfortable inspecting the cooling system yourself, take your Oldsmobile Aurora to a qualified mechanic for diagnosis and repair. Ignoring a coolant leak can lead to severe engine damage, overheating, and costly repairs.
