* Radiator: A crack or hole in the radiator itself is a common cause. The pressure in the system builds as the engine warms, and this pressure pushes water out even if there's a small leak.
* Radiator Hoses: These hoses connect the radiator to the engine. A crack, hole, or a loose clamp on a hose will leak coolant. This is often exacerbated when the engine is started and the system begins to pressurize.
* Water Pump: While less likely to cause a *sudden* large leak *right* at startup, a failing water pump's seal could be leaking. As the pump spins, it might start leaking more significantly once it's running.
* Heater Core: While less likely to cause a large puddle under the engine, a leak in the heater core (located inside the passenger compartment) can lead to coolant accumulating and eventually dripping down to the floor under the engine, *especially* after the car has been running for a while and the heater has been on.
* Engine Block Crack (rare but serious): A crack in the engine block itself is a far more serious issue and would require major repair or engine replacement.
You should NOT continue driving the car. Running the engine with a coolant leak can lead to overheating, which can cause catastrophic engine damage.
To determine the exact source, you'll need to:
1. Let the engine cool completely. Coolant is extremely hot when the engine is running.
2. Carefully inspect the entire cooling system. Look for wet spots, puddles, or signs of corrosion around the radiator, hoses, and water pump.
3. If you are comfortable working on cars, you can try a pressure test on the cooling system. This will help pinpoint the leak. (A pressure tester is available at most auto parts stores.)
4. If you're not comfortable performing this check yourself, take the car to a mechanic immediately. The sooner you get it checked, the better, to prevent more extensive damage.
Ignoring this leak could result in expensive repairs. It's best to address it promptly.
