The radiator and cooling system in your car is just as important and yet still prone to failure over time, as many of the other parts in your car. We’re going to take a quick look into what your radiator does, the typical problems that can occur, and what it might cost to carry out a car radiator repair or replacement.

So, with no further ado…

What does a car radiator do?

Your radiator is part of your car’s cooling system. Its job is to keep your vehicle’s coolant cool. It does this by passing the coolant (stored in a tank to its side), through the radiator’s core, which is cooled by a large fan blowing cold air over it. The hot air dissipates from the liquid, and the coolant is sent back around the hot engine to maintain the correct temperature—and the whole process starts again.

Most of the heat generated by your car’s engine leaves via the exhaust system, but it’s the cooling system—and your radiator’s job—to deal with the residual heat.

If the coolant levels are too low, or they’re leaking from the system—that’s when you have a problem.

How can you tell when there’s something wrong with your radiator?

  • The first and most obvious sign is that your engine will overheat, your temperature gauge will head towards the red end of the scale, and there could well be a lot of steam escaping from under your bonnet.
  • Your check engine light will illuminate whenever there’s a problem with your radiator.
  • You might spot puddles beneath your car where the coolant is leaking. The liquid is quite likely to be coloured. The colour will depend on the type of antifreeze in your coolant.
  • Wet patches may appear on or around the surface of your radiator and hoses.

How long does a car radiator last?

There isn’t really an average lifespan for a radiator. In time, and depending on the weather and typical usage, your radiator could last a lifetime. However, constant exposure to extreme weather conditions, dirt and dust, could add to its wear and expected lifespan.

How much does a car radiator repair cost?

Vehicle radiator repairs will vary in type, seriousness, and their costs will vary accordingly.

Depending on your make and model, a radiator repair or replacement could cost you anywhere between £150 and £500. With Fixter, you can save up to 30% compared to dealers, franchises, and other mechanics. Give our experts a call to see how much they can save you with our car radiator repair service.

Is my car leaking coolant or oil?

Oil is golden yellow when it’s new, and brown or black after regular use. Coolant, on the other hand, is typically coloured orange, red, blue or green.

If you think you might have a leak, monitor the levels in the reservoir before and after a journey. Use a marker or tape to register the level. If you place your marker when the engine is cold, be sure to wait until it cools down again after driving.

How to repair a car radiator leak

The simplest and most stress-free way of dealing with a leaky radiator, or something amiss in your cooling system, is to book it in for examination and repair with a qualified mechanic.

If you want to take on the job yourself, then we’ve got a few pointers to help keep you on track.

Preparing to seal a leaking radiator

Of course, you should have all the tools you’re going to use ready at hand, and the appropriate safety wear.

Because your radiator works under pressure, there’s a chance that it could spit out coolant or gas when you remove the cap, so get yourself some safety glasses too, just in case.

Many parts of your cooling system will heat up and could become quite hot, so a pair of gloves wouldn’t go amiss either.

Give your radiator time to cool down

If you’ve been driving your car, it could take an hour or two for the radiator to cool down. When the coolant is up to temperature, the whole system is pressurised. The system should be cold before you try and locate or seal the leak.

Clean your radiator

You’ll be able to spot any drips, leaks or damp patches if the radiator is clean. Use a hose or scrub with soapy water to remove grease and grime.

Examine your radiator thoroughly

When you start your engine, examine the radiator, its hoses, and the rest of the cooling system closely.

You may see water pouring out; there might be a slow drip; you might not even see any liquid pooling under your car, only a slow seep from a tiny crack. You need to be thorough, though, as there could be more than one area where the coolant is escaping.

Pressure testing

You can pick up a coolant pressure system tester from motoring and car part centres. This handy tool could help you locate the problem areas. They fasten to the radiator where the cap usually fits and allows you to pump air into the system, adding pressure. This will push air or coolant out of the leak, making it easier to detect by sight or sound.