Auto Express explains how antifreeze keeps your engine from overheating and why you should check your levels
As the name suggests, the primary function of antifreeze is to stop your car’s coolant freezing (with coolant being a combination of water and antifreeze). Everything from your standard variety Ford Fiesta, to premium cars like the Jaguar F-Type relies on this liquid, but to understand what it is, we need to know what it does.
There are channels inside an engine which allow coolant to circulate, removing excess heat from the engine block. The heated mixture is then taken via connecting pipes to a radiator, where heat is removed from the fluid. It is then pumped back into the engine to begin the whole process again.
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The problem is, when you turn your engine off, the fluid stops moving and the engine begins to cool. It’s especially important to keep an eye on your coolant if you live somewhere where temperatures drop below freezing. If the water in the coolant channels freezes, it can expand and cause stress on the engine block. The knock on effects of which can result in a wide range of problems, including coolant leaks or even a warped cylinder head.
On top of lowering the freezing point of the mixture, antifreeze also serves another purpose – it acts as a lubricant/projector for the engine internals. Most engines are made from either iron, or aluminium, both materials which can be eroded by water. Therefore, modern antifreeze coolant contains chemicals which protect the internals of and engine from corrosion – including the water pump, which is often located in awkward places that make repairs expensive.
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How do you check your car’s coolant level?
Well, there are two common ways to do this, and it depends on the cooling system your car has. Firstly, there are systems which have a coolant reservoir allowing the coolant level to change as the system heats up without dumping fluid. To check the level of a system like this, follow the steps below:
Check engine coolant on cars with a reservoir
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Check engine coolant on cars without a reservoir
There are also systems which do not have a reservoir. They may have an overflow tank where water can be released to, but it cannot return to the engine.
If, after checking coolant level of your car it is below the minimum, you will either need to top it up, or even better, drain the system and replace the coolant. A mechanic will be more than happy to replace your engine coolant for you.
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If you decide to do the work yourself, there are a couple of things to bear in mind. Firstly, most modern cars have completely sealed systems, meaning coolant should only need replacing if there has been a leak, so it may be worth investigating that sooner rather than later or the problem may continue to get worse. Also, the different types of antifreeze do no mix and can have adverse effects on your car, so make sure you get the correct one.
Have you had any coolng related horror stories? Let us know in the comments below…