Common Causes:
* Loose or Damaged Hose Clamps: These clamps secure the radiator hoses and other coolant hoses. If loose or broken, coolant will leak. This is a relatively easy and inexpensive fix.
* Cracked or Perished Radiator Hoses: Hoses degrade over time due to age, heat, and exposure to chemicals. Cracks or holes will cause leaks. Replacement is straightforward.
* Radiator Leak: The radiator itself can develop leaks due to corrosion, damage from debris, or simply age. Leaks might be pinhole-sized or larger. Repair may involve patching or replacing the radiator.
* Water Pump Leak: The water pump circulates coolant. A leak can occur from a failing seal or a cracked pump housing. Replacement is necessary.
* Thermostat Housing Leak: The thermostat housing can crack or develop a leak around the gasket. This is a relatively common point of failure.
* Head Gasket Failure: This is a more serious issue. A blown head gasket allows coolant to mix with engine oil (you'll see milky oil) or leak externally. This requires a major repair.
* Coolant Reservoir Leak: The plastic reservoir can crack or develop leaks, especially if it's brittle from age. Replacement is the solution.
* Heater Core Leak: This is less likely to cause a significant leak *under* the engine, but a heater core leak will certainly lead to coolant loss. The leak manifests more inside the cabin.
Troubleshooting Steps (don't attempt major repairs yourself unless you're experienced):
1. Safety First: Let the engine cool completely before inspecting anything. Coolant is hot and can cause serious burns.
2. Visual Inspection: Carefully examine all hoses, clamps, the radiator, water pump, thermostat housing, and coolant reservoir for any visible leaks, cracks, or signs of damage. Look for wet spots, stains, or traces of coolant.
3. Pressure Test: A mechanic can perform a pressure test on the cooling system to pinpoint the leak more precisely. This is the most reliable method for finding small leaks.
Important Note: Ignoring a coolant leak can lead to engine overheating and catastrophic engine damage. It's best to have a mechanic diagnose and repair the problem as soon as possible. The severity and cost of repair will depend on the source of the leak.
