Everyone knows the little red light on the dashboard that warns us of engine overheating. Often, a low coolant level is the culprit. But what actually happens if you drive without coolant? Today, we’ll explore this question and shed light on the serious consequences for your engine.
Even after a short time without coolant, the engine is at risk of overheating. The reason for this lies in the functioning of the cooling system. 
Diagram of a car cooling system lacking coolantThe coolant circulates through the engine block and absorbs the heat generated. The heated fluid is then passed through the radiator, where it is cooled down before the cycle begins again. If coolant is missing, the heat can no longer be dissipated.
The Fatal Consequences of Driving Without Coolant
“Driving without coolant is like a marathon without water for a human,” explains engine expert Dr. Markus Wagner in his book “Modern Engine Technology.” “The engine is extremely stressed and can suffer irreparable damage.”
The most common types of damage include:
- Scratched or cracked cylinder head gasket: Extreme heat can cause the cylinder head gasket to lose its sealing effect. Coolant can enter the combustion chamber and lead to engine damage.
- Warped cylinder head: High temperatures can warp the cylinder head, which also leads to serious engine damage.
- Piston seizure: Without cooling, the pistons expand in the engine block and can become stuck, resulting in engine failure.
The repair costs for such damage are enormous and can quickly exceed the value of the vehicle.
What to Do in Case of Coolant Loss?
If you notice while driving that the temperature gauge is rising into the red zone or the coolant warning light comes on, stop immediately! Turn off the engine and let it cool down. 
Person refilling coolant into a car engineNever open the radiator cap when the engine is hot, as boiling coolant can escape under pressure and cause severe burns!
Then check the coolant level. If it is too low, you should try to find the cause of the coolant loss. Possible causes are:
- Leaky cooling system (hoses, radiator, water pump)
- Defective cylinder head gasket
If the cause is found and fixed, you can refill coolant. Pay attention to the manufacturer’s specifications and use the correct coolant.
Prevention is Better Than Repair
To avoid getting into the situation of having to drive without coolant in the first place, you should regularly check the coolant level and refill coolant if necessary. The hoses and seals of the cooling system should also be checked by a specialist workshop at regular intervals.
More Interesting Topics About Cars
Are you interested in more tips and tricks about your vehicle? Then visit our website! There you will find exciting articles on topics such as “Car cooling without air conditioning” or learn everything about “Swedish heater” (likely referring to engine block heater or similar pre-heating systems).
Do you have questions about your vehicle or need help with repairs? Our experts are happy to help you with advice and assistance. Contact us today!
