Can Cold Weather Cause Antifreeze to Leak

Yes, factors such as cold weather can cause antifreeze to leak from a car radiator. The colder the weather, the more likely that fluid will freeze and expand inside the radiator.

Over time, this may cause damage to the fan or other components of the cooling system. So, today we will inform you more about how cold weather can make antifreeze leak.

What would cause antifreeze to leak? 

If your car’s antifreeze leaks, a few things could be causing the problem. In this section, we inform you of 8 causes of antifreeze leaking.

1. Improperly maintained radiator

Radiator failures can cause antifreeze to leak. A common reason for a radiator failing is improper maintenance, such as not topping off the coolant reservoir or leaking fluid.

Over time, corrosion and metal fatigue can also lead to leaks. In severe cases, cracks in the cooling system may allow liquid coolant to seep out and onto the engine block or surrounding areas.

2. Damage to the cooling fan or other components

Suppose the fan or other components that are responsible for circulating coolant inside the radiator are damaged. This can cause the fluid to seep out and onto the engine block or surrounding areas.

For example, this may occur if there is a broken wire in the fan motor. Additionally, debris accumulation on blades or impellers can also lead to damage and consequent leakage.

3. Defective hoses and fittings connecting the radiator to the engine block

Suppose the hoses and fittings connecting the radiator to the engine block are defective. This can cause liquid coolant to seep out onto the engine block or surrounding areas.

This may occur if there is a hole in one of the hoses. Additionally, if one of the hose connections is loose or worn out, it may fail when pressure builds up inside the cooling system.

4. Frozen gas cap

If the gas cap is frozen, this can cause it to twist off the fuel pump connector. When this occurs, liquid coolant may trickle onto the engine areas around it.

This may occur even if there are no broken hoses or connections between the radiator and engine block. In severe cases, a break in one of these lines may allow fluid to flow directly from the tank into the engine compartment.

5. Damaged or clogged radiator cap

When the radiator cap is damaged, this may cause coolant to seep out and onto the engine block or surrounding area.

This may occur even if there are no broken hoses between the radiator and engine block. In severe cases, a break in one of these lines (e.g., at an existing over seal) may allow fluid to flow directly from the tank into the seating compartment

6. Leaks in the cooling system hoses and fittings

Leaks in the hoses and fittings connecting the radiator to other engine components may cause coolant to flow from one area into another.

These leaks are distinct from the above holes because they occur regularly regardless of how fast an installation is (e.g., when there’s no leak within these systems, it still appears that liquid is leaking around them).

7. Defective thermostat or temperature sensor

If the thermostat or temperature sensor is defective, it will fail to adjust appropriately as the coolant warms. These sensors can recognize when fluid is leaking. Using that information, they will keep heater core temperatures within a safe range even with persistent leaks in cooling system hoses.

On later models of this vehicle (1997 & newer), these vehicles can also “learn” how much would be enough for an operating temperature target by monitoring fluid evaporation.

The sensor will automatically adjust to keep heater core temperatures at the preferred setting for a given temperature on that day and time of year.

8. Frozen water pump

One of the most dangerous leaks occurs when a water pump bearing collapses, freezing in place and significantly reducing its ability to move fluid.

This condition can often only be detected after the damage has already occurred; however, misdiagnosis by unscrupulous dealers who are more concerned with unloading the vehicle than clearing it may lead them to clear an obvious “head gasket problem incorrectly.”

The resulting overheating will cause damage over time, including at least the engine oil. Frozen heat exchangers are also a factor when water pump bearing failure releases trapped moisture which freezes in place and severely reduces this bearing’s ability to move fluid.

Why does coolant leak only when it’s cold?

When the outside temperature starts dipping below the freezing point, your car’s antifreeze starts to thaw. This liquid is made of ethylene glycol, water, and glycerin and is used to counter the freezing and thawing of engine parts.

When the antifreeze begins to thaw, it leaks out of the car’s joints and hoses. Therefore, antifreeze can leak when it’s cold outside – because it’s liquid and doesn’t have a solid form.

What are the signs of an antifreeze leak? 

The most common sign of an antifreeze leak is a puddle on the ground. If you see this, it’s time to take your car to a repair shop. Other signs include wet carpet, blue ice around the car, and steam coming out of any hoses.

How to find out where the coolant is leaking from?

If you are experiencing a leak from your cooling system, the first step is to determine where the coolant is leaking. This can be done by following the coolant’s route from the radiator, down through the system, and onto the ground. Once you have determined the source of the leak, you can start to fix it.

Suppose the leak is coming from the radiator. You will need to remove the radiator and replace the faulty part. If the leak is coming from a hose or other component, you will need to replace that component. If the leak is coming from the system itself, you will need to replace the entire cooling system.

Can you drive my car if antifreeze is leaking?

Driving your car while an antifreeze leak is occurring is not recommended. The liquid may contain harmful toxins, which could be absorbed into the bloodstream if it meets the skin. In addition, driving with a leaking system can cause severe damage to your car.

How long can you drive on a car that is leaking antifreeze?

It is not recommended to drive in a car leaking antifreeze for more than an hour. Driving any longer could result in severe damage to the car.

Is a coolant leak expensive to fix?

A coolant leak can be expensive to fix, depending on the extent of the damage. For example, if the coolant has leaked into the engine, it might require a complete engine replacement. If the coolant has leaked out of the system and onto the ground, it might only require a repair kit to fix the problem.

Regardless of the extent of the damage, getting it fixed as soon as possible is always the best option. The longer the leak persists, the greater the risk of additional damage and potential engine failure.

Why is your car leaking antifreeze but not overheating?

There are several reasons why a car may be leaking antifreeze but not overheating. The most common reason is that the thermostat is not working correctly. If the thermostat is not sending a correct signal to the heat exchanger, then the car will not be able to cool properly.

Overheating can also be caused by several other issues, such as a blown head gasket, cracked radiator, or faulty cooling fan. You will need to take your car to a mechanic to diagnose the problem. They will be able to diagnose the issue and recommend a solution.


Although antifreeze is meant to protect your car’s engine from freezing and subsequent damage, it can still leak when cold outside. In this blog, we have described the various causes of antifreeze leaking and given you handy tips on preventing it from happening in the first place.

Make sure to read through the article and take the necessary precautions to keep your car safe in (or even outside) cold weather.

Garry Rodruguez

Hey! It's me, Garry Rodriguez, A researcher. I'm passionate about learning new things & sharing my knowledge with information enthusiasts.

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