
No, you should not pour cold water into a hot engine if your car is overheating. Doing so can cause catastrophic thermal shock, cracking the engine block or cylinder head due to the extreme and rapid temperature change. The immediate action is to safely pull over, turn off the engine, and let it cool down completely on its own, which can take 30-45 minutes. Only then can you slowly and carefully add coolant or a 50/50 coolant-water mixture to the radiator (not the overflow tank) if the level is low.
An overheating engine indicates an underlying problem, such as a coolant leak, a faulty thermostat, or a broken water pump. Simply adding water is a temporary fix at best. Modern engines operate at high temperatures under pressure, and using plain water can lead to corrosion and freezing in cold climates. The correct response prioritizes safety and preventing further damage.
| Action | Correct Procedure | Risk of Incorrect Action |
|---|---|---|
| Engine Status | Turn off engine immediately. | Continuing to drive can cause severe engine seizure. |
| Cooling Down | Let it cool naturally for 30+ minutes. | Pouring cold water can crack the engine block. |
| Checking Level | Check coolant level in radiator after cooling. | Opening the radiator cap when hot can cause severe burns from erupting steam. |
| Adding Fluid | Add a 50/50 coolant-water mix to the radiator. | Using only water risks corrosion and freezing. |
| Next Steps | Drive to a mechanic for diagnosis of the root cause. | Ignoring the underlying issue will lead to repeated overheating. |
The safest plan is to call for a tow truck. If you must drive a short distance to safety, turn on the heater to its highest setting and fan speed. This draws heat away from the engine into the passenger cabin. Drive carefully and stop immediately if the temperature gauge rises further.


