The radiator in your car is a vital component to the smooth running of your engine, it helps keep the engine's temperature inside a safe range and prevents overheating.  

There are a few ways your radiator can become damaged and a few different ways to tell when it needs replacing or repairing. Read on to find out how much a radiator repair costs.  

How Much Do Car Radiators Cost to Replace? 

The average cost to replace a car radiator in the UK is between £300 - £950. 

This is based on all other components such as hoses, the water pump, and coolant tank being in good working order. As with most car repair tasks, the cost will be directly affected by how complex the vehicle is.  

Typical radiator replacement costs per make and model 

Radiator replacement cost will depend on things such as; location, age of car, etc, but most importantly the make and model: 

• Toyota Aygo - £300 
• Ford Fiesta - £325 
• Mazda 3 - £400 
• Fiat 500 - £325 
• BMW 3 Series - £450 
• Mercedes C-Class - £510 
• Volvo XC90 - £415 

Split the cost with Bumper at trusted repairers near you. 

How Much Do Radiator Leaks Cost to Fix? 

Expect to pay anything from £50 - £600 to fix a serious coolant leak from your radiator or cooling system in general. 

However there are a few other components that can cause leaks, we discuss those in more detail below.  

What Does Car Radiator Do? 

The radiator is the largest component in the cooling system, and acts as a heat exchanger to remove heat from the engine coolant, allowing it to run at its optimal temperature. 

Coolant is pumped around the engine and radiator by the water pump, which is usually driven from the cambelt. The expansion tank also connects to the top of the radiator to act as a reservoir for coolant after it has passed through the radiator. 

5 Signs Your Car Radiator Needs Replacing 

As the radiator is instrumental in the engine's coolant system, any changes in the engine temperature from normal should warrant a radiator and coolant check. Other symptoms may include: 

1. Engine running hotter than usual 
2. Engine overheating during normal use 
3. Coolant level drops below the minimum level after refilling 
4. Coolant is leaking from the car after parking for a period of time 
5. There is damage from an accident or strikes from road debris 

How Long should a car radiator last? 

With a modern alloy car radiator, providing the coolant is replenished and flushed as per your service interval, and no damage is sustained the radiator on many cars can last the lifetime of the car.

How long do car radiator repairs take? 

It’s always best to ask your garage or mechanic the expected completion time, but we’d suggest planning to be without your car for at least half a day. For premium and performance cars, budget more time, as these types of vehicles generally require more disassembly.  

Most garages will only be interested in replacing the radiator, as the cost of buying and fitting a new one takes around the same amount of time and money as investigating and repairing an old one. 

Can I fix a car radiator myself? 

If you’re a reasonably accomplished home mechanic, replacing a car radiator shouldn’t be much trouble. If it's your first experience with fixing things on your car, however, we’d suggest you consult a garage for assistance. 

The process of replacing a radiator will differ from vehicle to vehicle, but is likely to generally involve: 

• Draining the coolant system 
• Removing ancillary components such as air filters/intake pipes and undertrays 
• Removing the radiator 
• Reinstalling in reverse order 

There are fixes you may be able to tackle at home, such as replacing a broken radiator cap or straightening the radiator fins with a radiator tool. 

Can I fix a radiator leak at home? 

If your radiator is leaking, it needs to be fixed as soon as possible. The more you drive the car, the more coolant will leak out, as the system is pressurised with the engine running. We would not recommend using a radiator leak-stop product.  

Whilst radiator leak stoppers may be okay to use in an emergency situation, it can cause further damage in some cases Radiator leak products use a chemical solution that congeals at the source of the leak and blocks it. 

Unfortunately they usually only offer a temporary solution, and there are many other coolant routes that the substance can block, such as the narrow passageways in the engine head, or cooling pipes going to your turbo. 

Can I fix my radiator with an egg? 

A trick that may get mentioned by older drivers when faced with a leaky radiator is to crack an egg into the radiator or expansion tank. Whilst it may seem absurd, there are many accounts of this working in much the same way as off-the-shelf radiator leak stoppers do.  

However, unless in an emergency - and on the way home from the shop! - we wouldn't recommend adding an egg to your radiator or expansion tank. As well as creating a bad smell, your mechanic won’t thank you when the radiator needs to be replaced a short while later! 

What Causes A Coolant Leak 

An engine's coolant system is made up of many different components, all of which can cause leaks or the disappearance of coolant. 

• Broken expansion tank - these are usually made of plastic and are exposed to high heat and pressure, which can sometimes cause hairline cracks to form, especially when under pressure. 
• Split hoses - The radiator will have multiple rubber hoses connecting it to the engine, if any of these develop a split, they will leak coolant from the system. 
• Head Gasket issues - coolant passes through to the engine head from the block. If the headgasket is blown, coolant can enter the combustion chamber, oil channels or even escape the engine altogether. 
• Leaking water pump - The water pump creates coolant flow around the radiator and engine. If the sealant or gasket between the pump and engine block breaks down, water can leak from here too. 

Can I drive with a leaking radiator? 

Your car may well still drive fine, and if the leak isn't too severe, it may not overheat even on longer drives. However, all it takes is an unexpected traffic jam or unplanned journey needed, and you could cause thousands of pounds of damage to your car.  

An overheated engine can easily cause a blown head gasket or warping of the head and engine block. Both events will require extensive mechanical work to fix, and a whole load more cost.  

Speak to the experts 

With Bumper, you can split the cost of repairs into monthly payments at no addtional cost. 

Apply online before booking in with the garage and choose from 1,000s of trusted repairers on our network. 

Author - Joseph Law

Joseph has been writing about cars for over seven years and writing for Bumper for over two, blending his passion for automobiles with a talent for storytelling.

Joseph has written about engineering and cars for Autozilla, Komaspec, and several engineering manufacturers. When he's not writing or tinkering with one of his five cars, Joseph dreams of owning an Alfa Romeo 33 Stradale.