Can I Drive With a Cracked Radiator?

Your car engine is a marvel of engineering, a beast that powers about two metric tons of metal over long distances. To do this requires combustion, a process where a lot of heat energy is generated.

As impressive as this is, the heat energy could damage the engine, and this risk is counteracted by the existence of a cooling system that lowers the car’s temperature through the circulation of a coolant.

Essential parts of the cooling system include hoses, your engine, the radiator, the pump, the cooling fan, the thermostat, and a radiator. The radiator is a crucial part of this system.

Before looking at how you can temporarily fix a leaking radiator and how far you could drive your car in such a situation, it is essential to understand its role and how it works.

How does the radiator work?

Being an important part of the cooling system, the radiator’s primary purpose is to prevent the car from overheating. The engine coolant itself is a liquid that absorbs heat from the engine. The coolant is released from the radiator and pumped through the engine when the vehicle starts.

cracked radiator

After the liquid absorbs the heat, it goes back to the radiator, which helps to dissipate the heat from the coolant. It does this through the metal fins, which release the energy to the outside of the car. Air that is lower in temperature flows through the radiator when the vehicle is idle, and the cooling fan would typically blow extra air to keep the coolant temperature low.

After the coolant passes through the radiator, it circulates the engine again for another round of temperature optimization.

How can radiator leaks appear

Since radiators are made for temperature absorption, it makes sense for car makers to use metals with high thermal conductivities in their construction. Radiators in most modern cars are made of aluminum, but also copper and brass.

While these materials are durable in their own right, they are also vulnerable to wear and tear and can present you with a cracked radiator. Things that might cause your radiator to crack include:

  • Accidents

Even minor accidents could despoil the state of your radiator as it’s located in the front of your car.

  • Rust and corrosion

All metals are vulnerable to rust. Rustiness compromises the integrity of the metal and leaves it open to cracks. Dirty coolants can cause corrosion.

  • Impaired thermostat or cooling fan function and leaking head gasket

These problems could cause overheating, which would, in turn, cause high coolant pressure due to the expansion of the coolant liquid in the radiator. The pressure would then cause cracks

  • Temperature fluctuations

There are a host of climatic conditions that could cause stress to your radiator. Heat in summer could imbalance the radiator’s cooling by outside air, and chills in winter could freeze the coolant liquid.

  • Debris

Debris could easily get into the radiator if you live in rocky or sandy places. It would not do your radiator any favors

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Can I drive with a cracked radiator?

The short answer is yes. You can drive with a cracked radiator for a limited time, but it is never advisable. There are cases when you can edge it due to necessity, but in most cases, it is never advisable to do so in the long run.

If the crack is tiny and you only just noticed, it is within reasonable bounds to drive short distances, after which the radiator should be fixed IMMEDIATELY. If the crack is considerably large, it is best just to leave your car idle and focus on fixing it as soon as possible. You would not want to incur extra charges to rectify more significant problems.

How far can you drive with a broken radiator?

If you notice your radiator is cracked, but you’re feeling adventurous nonetheless, you should be aware of just how long your radiator can take you before you get into major engine issues (debilitating issues would most likely arise).

The answer to this lies mainly in the size of the leak and the make and model of the car. If there is a small leak, you could drive the car for months as long as you top up the coolant. If the leak is considerably bigger, you might be able to drive for a couple of miles only.

Most new models can offer much on performance without tasking enough to overheat. Sources that have tried this mention that driving a car with a small crack for 4 hours on an open-road journey is possible.

For bigger cracks, it is recommended to have a tow truck come, as the coolant will most likely leak out in just a couple of miles. You would have to watch your temperature meter, though.

Although this might sound counterintuitive, drive slower than usual for a higher chance of reaching your destination. It will help to have some water in your vehicle and top up the coolant as soon as the engine temperature starts to rise.

A better solution in this situation is to try and do a temporary fix.

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How can I temporarily fix a cracked radiator?

Short of replacing the radiator with a new one, a great temporary fix for radiators is the use of adhesives to seal the crack. While not all radiators would respond to this, it is a valid method to try.

The method should depend on what kind of material your radiator is made of and where exactly the crack is. One can also weld the crack, use epoxy, or sandpaper the crack.

Can I use epoxy on any type of material radiator?

Yes, you can use radiator epoxy on any type of radiator. Although an easy DIY solution, remember that epoxy will only temporarily fix the leak. It is important to address the issue and have a mechanic do the repair as soon as possible.

Depending on where the leak is located, you might have to replace the radiator. If lucky, sometimes you could end up replacing just a hose.

Is JB Weld good for fixing a cracked radiator?

JB Weld offers a wide range of products for fixing tank and radiator leaks. They provide solutions for fixing plastic, composite, or metal radiators, and although some of the products are advertised as permanent repairs, I would still use them as a temporary fix.

Is a cracked radiator expensive to fix?

Radiator maintenance prices usually are not very high unless you are replacing them. The prices would, of course, be dependent on the make and model of your car. If you’re just going to replace the coolant or fix the crack, you should expect to spend upwards of $80.

Replacing the radiator would be more expensive because the cost of the new radiator is included, along with labor costs from the mechanic. The overall price you would spend on replacement would be around $300-$900, so it’s best to take preventive measures to avoid spending this much on replacement.

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How do you tell if your radiator is cracked?

There are a couple of signs you should look out for to identify a cracked radiator. These include:


Your radiator is much needed for cooling the engine down. If it is cracked, the engine will start to overheat. Keep an eye on the engine temperature gauge inside the car.

Leaking coolant

If your radiator is cracked, this is the first thing you should look out for. It would typically pool underneath your car. You would also notice your vehicle’s alert for low coolant levels constantly going off.

Discolored coolant

Rust might affect the consistency of the coolant.

Frequent refills

If you find yourself constantly needing to top up your coolant, there is definitely a leak in the cooling system. It might be a cracked radiator or a leaking hose, but you need to get it inspected sooner rather than later.

What happens if you don’t fix a radiator leak?

Simply put, your engine will overheat, and you could end up with a blown engine. An overheated engine is bad news for your car in any case. Most parts will become compromised, and you will be faced with a hefty repair bill.

Although some repairs can wait, a leaking radiator is definitely one of those. Addressing the issue should be a top priority, and it is important not to risk driving the car unnecessarily.

Final words

A cracked radiator should not be treated lightly, as it can result in a blown engine. Most new cars do have systems that will prevent the engine from blowing up in case of overheating, but older models lack this feature.

You should perform regular checks to ensure that the coolant is in good condition, and in case you need to top up frequently, you should look for a leak in the cooling system.

Replacing coolant every two years or 30,000 miles will ensure your engine’s cooling system is working properly. Over time, the coolant loses its properties and will start corroding the radiator. And this is how you end up with a leaking radiator.

Remember, maintenance is key to a happy car!