Summer Heat & Radiator Cracks – Causes Behind A Cracked Radiator

Have you ever tried starting your car and it won’t just work?

You may even try to jumpstart the battery to see if there is anything wrong with it.

Most car owners can relate to this.

Your car doesn’t just stop working. Most times, it would have shown warning signs that you intentionally or not intentionally choose to ignore.

If after you get it checked and you discover you have a cracked radiator, the next question that comes to mind is: “how come?”

You are about to find answers in this article.

How do radiators crack?

The radiator is a vital part of a vehicle. It is one of the components of your car’s cooling system that helps remove heat from getting to the engine.

While the radiator is important to prevent engine overheating, it can develop issues as time goes by. It could crack.

There are different factors that could be responsible for a cracked radiator. They include:

Faulty Thermostat

One of the reasons why you could have a cracked radiator is if the thermostat (temperature monitor) is faulty.

It is an important feature responsible for monitoring the engine’s temperature. It determines when to add coolant or water to the radiator to prevent overheating.

However, if you have a faulty temperature monitor, it would be impossible to detect the engine’s temperature, thus, feeding the radiator with coolant when not necessary or when it’s past filling time.

And your car’s temperature monitor can only develop faults when there is too much coolant in the radiator, resulting in high pressure inside the radiator and ultimately breaking this component.

Leaking or Broken Head Gasket

The way radiator cracks due to a damaged temp. Monitor is also the same way it does for a leaking or broken head gasket.

The head gasket is the barrier between the engine and cylinder head. It prevents coolant from getting to the engine directly.

So, it is definitely a part that shouldn’t be damaged at all.

Road Debris

For someone who drives on off-roads a lot, a cracked radiator is inevitable. Your radiator can be hit by rocks or road debris, and the impact may damage it.

Bad Radiator Fan

Radiator fans are designed to pull outside air into the vehicle to cool the coolant.

If there is a problem with the radiator fan, it may be impossible to pull air, causing the coolant system to misbehave and then the engine to overheat.

Ultimately, you will experience radiator cracks.

Anomal Weather

Weather has an influence on how a radiator works.

In hot weather, the radiator overworks, consuming too much coolant to prevent engine overheating.

In cold weather, the coolant could freeze and expand inside, causing radiator cracks.


If the radiator’s metal fins or caps become rusty from long use, it could crack.

What are the signs of a cracked radiator?

Before you have a damaged radiator, you must have experienced certain things. These are warning signs that you need to replace your vehicle’s radiator.

They include:

Leaking Radiator Fluid

One of the first signs of a cracked radiator is a coolant leak.

The coolant is a transmission fluid that often appears a bright color – it could be yellow, green, or pink.

So, if you park and you observe liquid like this underneath your car, that means you have a radiator leak.

Constant Drop in Coolant Level

Apart from radiator leaks, if the coolant level drops quickly, you should suspect a radiator crack. The low coolant level is also often a result of a leaking coolant.

Engine Overheat

Another sign of a radiator crack apart from coolant leaks is an overheating engine.

If you have your engine running at high temperatures because the radiator fluid isn’t being supplied optimally, overheating would definitely happen.

If the issue persists, it could cause engine damage.

Radiator Cap Corrosion

Discoloration or corrosion around the radiator cap is also a sign of a broken radiator.

What happens if my radiator cracks?

If you have a cracked radiator due to a broken temperature monitor or head gasket, a series of things would happen.

First, the cracked radiator would allow the transmission fluid to leak from the coolant system to underneath your car.

Secondly, the engine starts getting hot due to the low amount of radiator liquid and that can cause overheating.

Prolonged overheating can cause significant damage to the engine.

Besides, a low coolant level affects the entire cooling system such that the water pump won’t get lubricated properly-, and ultimately fails.

Is it Safe to Drive With a Cracked Radiator? What Could Happen?

It isn’t. In fact, it is extremely dangerous.

When you have a cracked radiator, your car doesn’t stop working immediately. It may take some days before you start noticing certain things.

However, if you are lucky to discover the crack, you should stop driving and get a replacement.

If you keep driving with a radiator crack, your pistols will snap, eventually causing severe damage to your engine.

And with a damaged engine, your car automatically breaks down. But before it breaks down, you may lose control which could cause a serious road accident.

That being said, if you are driving and you notice steam coming out from your vehicle’s hood, you should park immediately and leave the vehicle.

When it cools down, you can now get the radiator replaced.

How Long Can You Drive With a Cracked Radiator?

The purpose of a radiator is to keep the engine cool. But what happens if it cracks while on a journey, how long can you drive?

Ideally, you may be able to move within 5 to 10 miles with a cracked radiator but at low speeds.

However, within that distance, you should start planning how to get it fixed before further destruction or damage.

The Cost of A Cracked Radiator

If there are holes or cracks on your radiator, you need to get a replacement as soon as possible.

In that case, you should budget between $700 to $1000 to fix the problem. 

The replacement cost and repair cost vary depending on the car model. You may even not spend up to $300 if you do it yourself. 

Besides, added to the fees is labor cost.

How to prevent radiator cracks?

Monitor the Radiator Fan or Cooling System Often

One of the things you need to do to prevent cracks in your radiator is to constantly monitor your radiator fan or cooling system in general. 

They are the most consequential parts because they are responsible for cooling the engine and making sure it doesn’t overheat.

Hence, if you notice you have a bad radiator fan, you should replace it at an auto repair shop immediately.

Observe the Coolant System

There is so much observing the coolant system of your car can do. 

If this feature isn’t maintained properly, it could leak, reducing the level of coolant in the vehicle. 

And when the coolant level is low, what can be provided to the radiator to cool the engine is limited.

You can also check underneath your vehicle for a leak.

Replace with Clean Coolant

A dirty coolant can be one of the reasons why you are experiencing issues with your radiator. When a coolant is dirty, it could clog the radiator. 

If the radiator gets too clogged, it could expand, and eventually crack.

But before that happens, you should endeavor to fill your vehicle with a clean coolant and make sure it doesn’t leak.

Monitor Car’s Temperature Often

Finally, you should always monitor your car’s temperature. 

Sometimes, it isn’t advisable to rely on the temp. monitoring device because it could be faulty with you realizing on time.

So, while you use the device, you should also make physical checks and observe the weather so you don’t have issues with your radiator anymore.


How do radiators crack?” The simple answer: improper maintenance of your car.

A damaged radiator is very dangerous because not only does it destroy your engine, but is capable of causing serious accidents while driving.

If you don’t want to experience issues on the road, you should make sure to have your car checked regularly and change important parts that need replacement.

Overall, no one can maintain your car better than you. 


Dean Alvarez, TireForge Head Author

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