Skip to Content

What Happens If Water In Radiator Freezes? [ Know Everything ]

What Happens If Water In Radiator Freezes? [ Know Everything ]

Running your car in cold temperatures invites several mechanical issues. Among these, you might end up in a mess if water freezes inside your car’s radiator. This happens to be one of the most dreaded and agonizing troubles for car owners.

Experts recommend using a branded antifreeze or coolant in your system. However, if you have been using water rather than the recommended agents, it might freeze inside the radiator.

This would result in an excessive amount of internal pressure. Sometimes, frozen water in the car’s radiator can inflict severe damage to the engine.

Let’s explore this topic deeper, and we are going to discuss the exact conditions when water might freeze in the radiator. Besides, we have briefed up the viable solutions that should help in case you have frozen water in your radiator.

What happens if water in radiator freezes?

When water freezes inside the radiator of the car’s engine. It won’t be able to circulate. Besides, you would notice overheating issues in the engine even when the temperatures remain low. With a frozen radiator in your car, there would be no steam. Eventually, it wouldn’t be possible to shut off your engine until it seizes.

Experts recommend not using water without any antifreeze or coolant in the engine’s radiator. Rather they recommend using an antifreeze, which would be safe for your car.

When water gets into the metal parts of the radiator, it can oxidize the material and result in rusting. The water pump and the impeller, both of which have metal in them, are susceptible to rusting.

In these situations, no coolant would flow through the engine’s block from the radiator. This can inflict severe damage to the mechanism, and you would end up with expensive repairs.

So, if you want to use water in the radiator, make sure to go with distilled water. Besides, tap water or bottled water would be fine for the radiator.

However, bore water or tap water contains traces of minerals. This implies that when you use this water, it would leave deposits in the cooling system. As a result, the radiator would be susceptible to corrosion, which would eventually rob it of its lifespan.

What temperature will water freeze in radiator?

If you have been using water in your radiator, it might freeze at -36 degrees Fahrenheit. So, when you drive in extremely cold conditions, it would be wise not to use water in the radiator of your car’s engine. Rather, you can go with an antifreeze.

What do you do if your radiator is frozen?

In case the radiator of your car freezes under extremely cold conditions, follow these recommendations to avoid further damage.

1. Make sure not to run the car

If you run your car with the radiator frozen, it might lead to overheating of the engine. Therefore, you need to park the vehicle in a warm place and let the frozen radiator thaw.

Now you need to put the car’s engine on and let it warm up gradually. This way, you can slowly loosen the cooling system up. In the process, the fluids would start moving once more.

Unless you have a steady flow of antifreeze or coolant, the engine might overheat quickly. At times, it can even explode as the pressure would mount due to the blockages in the cooling system.

2. The engine must thaw

The engine might take as long as two days to thaw out completely. Particularly, it would take time to thaw when the conditions outside are still cold. However, if you manage to move the car to a shelter or covered garage, it might respond faster.

Now, you must speed up the process by using a fan heater.

Place this device in front of the radiator, so that the air flows directly to the car. The heat would help melt the frozen water in the engine’s radiator. Besides, make sure not to drive your car until the frozen system has completely thawed.

After this, you have to drain the cooling system and flush it. Use a high-grade antifreeze or coolant to replace the fluid. This ensures that the radiator would have the right kind of protection, regardless of the weather conditions outside.

3. Put the antifreeze

When you fail to replace the coolant in the engine of the car, it tends to freeze under extreme temperatures. When you get the system unfrozen, put in a new antifreeze after draining the old coolant out.

When the radiator freezes, you don’t have many options but to wait and let the system thaw. Therefore, experts recommend checking the level and strength of the antifreeze or coolant in your system before the arrival of winter.

When you purchase the antifreeze or coolant, make sure to go for an equal proportion of ethylene glycol-based agent. This solution would keep your car protected, despite the freezing conditions around.

In case you don’t know how to prepare the cooling fluid, reach out to your local garage, and the experts will prepare the ideal strength of the cooling fluid or antifreeze for you.

Can frozen water crack an engine block?

Yes, frozen water can lead to cracks in the engine blocks. The engine block might crack when you put excessive water in the cooling system without adequate antifreeze.

This happens because the frozen water expands, exerting huge pressure on the engine block. Therefore, experts recommend checking the coolant and antifreeze strength before the onset of winter.

Will antifreeze melt ice in the car’s radiator?

The function of antifreeze is to minimize the water’s freezing point, so that it doesn’t freeze easily even if the external temperatures are cold. However, antifreeze cannot make any difference in the melting point of ice. This is the energy required to transform ice into water, both of which remain at 0 degree.

Will antifreeze defrost ice in the radiator of the car?

Some of the reputed brands have come up with antifreeze capable of melting ice in the engine’s radiator. Firstly, you need to prepare the area where you want to work. Now try doing away with as much ice as you can. You can also try using warm water to melt the ice before you apply the antifreeze.

What happens if the coolant freezes or becomes hot?

In case there is coolant in the system, and it freezes, it would get seized up. Besides, it would result in cracks in the lines of your system. When the coolant freezes, it expands. On the other hand, when the coolant becomes extremely hot, it can damage your car’s cylinder head and engine.

How does antifreeze work in winter?

Antifreeze can prevent the water present in the radiator of your car’s engine from freezing during the colder months. It diminishes the freezing point of the fluid.

With a drop in the temperature outside, the coolant circulates all the way inside the engine. This ensures that every part of your engine, including the radiator, has the same temperature.


It would be dangerous for your engine to operate without a good-quality antifreeze or coolant. Unless absolutely necessary, don’t try to operate your car without having the antifreeze or coolant.

The vehicle can hardly run for a minute or so without the coolant. The amount of damage your engine would incur largely depends on the strength of the blockage and the temperatures outside.

It wouldn’t be wise to risk your car’s engine amidst freezing temperatures outside. Therefore, you should have proper coolant or antifreeze in your engine. In spite of this, if water freezes inside the radiator, you already know how you can sort the issue out.