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Cracked Car Radiator (Causes & Fixes)

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  • 7 min read

Last Updated on: 7th September 2023, 12:47 am

The radiator in your car plays a super important role in keeping your car’s engine cool. It does this by making sure the coolant doesn’t get too hot (it should be around 90-105°C or 195-221°F).

If your car radiator gets a crack, it can cause big trouble for your car and you might end up having to pay a lot for repairs. This can happen for lots of reasons like getting hit by stuff on the road, or if the coolant gets too hot, if there’s too much pressure, or if the temperature fluctuates.

In this article, we’re going to figure out why radiators get cracks, what to look for if you think yours might be cracked, and what you need to know if you think your radiator has a cracked.

Cracked Radiator Causes

There are quite a few reasons why a radiator might get a crack. Let’s take a look at some of the main ones.

  • Changing coolant temperature
  • Debris hitting radiator
  • Bumps and bangs
  • Radiator fan issues
  • Dirty coolant
  • Too much pressure
a cracked radiator

1. Changing Coolant Temperature

If the temperature of the coolant keeps going up and down, the metal of the radiator can stretch and squeeze. This can put a lot of heat stress on the metal and can end up making the radiator crack.

2. Stuff on the Road

The radiator is usually at the front of the car, so it’s easy for it to get hit by rocks and other things that get thrown up by other cars’ wheels.

3. Bumps and Bangs

If your car gets into a collision or gets hit by something, it can damage the radiator and cause it to crack.

4. Radiator Fan Problems

If the fan that’s supposed to cool the radiator isn’t working right, the radiator can get too hot and crack.

5. Dirty Coolant

Over time, the coolant can get dirty and blocked up. This can mean it doesn’t cool as well as it should, and that can make the radiator crack.

6. Too Much Pressure

If there’s too much pressure from the coolant fluid inside the radiator, it can make the metal crack.

Even though these are the usual reasons a radiator might crack, they’re not the only ones. There could be other things going on too.

Signs of a Cracked Radiator

Here are some easy-to-spot signs that your car’s radiator might be cracked.

  • Coolant Level Going Down: If you see that the amount of coolant in your car is getting lower, this could mean your radiator has a crack.
  • Mucky Radiator: If there’s muck or bits in the coolant or the radiator, this could mean the radiator is leaking.
  • Car Getting Too Hot: If your car is getting hotter than it should, this could mean the coolant is leaking out through a crack in the radiator.
  • Coolant on the Ground: If the radiator is cracked, it can make the coolant leak out onto the ground. You might see a puddle of liquid under your car.

Other Signs

Below are a few more signs that your car’s radiator could be cracked.

  • High temperature gauge
  • Heater not working correctly
  • Coolant looks different or smells sweet
  • Weird engine noises
  • Bubbles in coolant

High Temperature Gauge

If the temperature gauge in your car is often higher than it usually is, this could mean your radiator has a crack.

Heater Not Working Right

If your engine is getting too hot often, and if the heater in your car isn’t working as well as it usually does, this could be because the radiator is leaking coolant because of a crack.

Coolant Looks Different or Smells Sweet

If the coolant has changed color or if there’s a sweet smell coming from the engine, this could mean the coolant is mixing with oil. This could be a sign that the radiator is cracked.

Weird Engine Noises

If your engine is making strange sounds like knocking, ticking, or hissing, this could be because it’s getting too hot. This could be a sign that the radiator is cracked.

Bubbles in the Coolant

If the radiator is cracked, the coolant can leak out and mix with air, making bubbles. You might see this if you look at the coolant reservoir or the coolant in the radiator.

Cracked Radiator or a Head Gasket Issue?

Figuring out if a radiator is cracked or if there’s a problem with the head gasket can be tough. A skilled mechanic can help find out what’s wrong by doing a pressure test on the cooling system.

One clue to help you know if it’s a head gasket problem or a cracked radiator is to look at the engine oil filler cap. If it looks creamy and frothy, it might mean the head gasket is busted.

damaged head gasket

Is It Safe to Drive With a Cracked Radiator?

Driving when your radiator has a crack is risky and you should try not to do it. If your radiator is cracked, your engine can get too hot really quickly, and this can damage the engine and other parts of your car.

The best thing to do is to get a broken car radiator fixed or swapped for a new one as soon as you can.

Can You Fix a Cracked Radiator?

Sometimes, you might be able to fix a radiator that’s cracked. But a lot of the time, it’s a better idea to get a whole new radiator to make sure your car works as well as it can for as long as it can.

A mechanic can help you decide if it’s better to fix the radiator or replace it.

Do You Have to Get a New Radiator if It’s Cracked?

If the crack in the radiator is pretty small and can be fixed, then you might be able to just repair the radiator.

But if the crack is big or if the radiator is really damaged, then you’ll probably need to get a new radiator.

Cost to Fix or Replace a Cracked Radiator

How much you’ll have to pay to fix or replace a cracked radiator can change depending on what kind of car you have, and whether you get the work done by a mechanic or at a place that specializes in fixing radiators.

It’s a good idea to get quotes from a few different places before you decide what to do.

How Big of a Deal Is a Cracked Radiator?

A cracked radiator can make big problems for your car. It can make your engine get too hot, which can damage the engine and other parts of your car.

Also, it can make the coolant leak out, which can make the coolant level go down and make the cooling system not work as well.

Can a Cracked Radiator Cause a Car to Fail an Inspection?

A cracked radiator could make your car fail an MOT or an inspection, because it shows there’s something wrong with the car’s cooling system.

It’s a good idea to get a cracked radiator fixed or replaced before you take your car in for an MOT or emissions test.


A cracked radiator can make big trouble for your car and might mean you have to pay a lot to get it fixed.

It’s good to know what to look out for, like if the coolant level goes down, if there’s muck in the radiator, if your car gets too hot, or if there’s coolant leaking out.

If you think your car’s radiator might be cracked, it’s a good idea to get a mechanic to check it out and get it fixed or replaced as soon as you can.

References & More Information

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  • Andy Lewin

    Andy Lewin is a senior mechanic, ASE qualified master technician, and an experienced automotive engineer. He's passionate about serving the automotive community with the highest-quality and trustworthy information on all things automotive. He loves to write about car repairs, maintenance, car modifications and tuning, faults, and much more.

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