During the summer months, temperatures can get extremely high both inside and outside the car. Sitting in slow moving traffic can quickly cause engine temperatures to soar, which can take its toll on tired and poorly maintained cooling systems as there’s less air passing through the radiator. As a result, the vehicle relies solely on the efficiency of the radiator and cooling fans to keep temperatures down. If the cooling system is blocked or the fluid level is low and leaking, you may soon see the temperature needle climb into the red.

Over the last 12 months, our Roadservice team received more than 5000 callouts related to cooling systems. Most of these were in larger cities and areas of New Zealand with a warmer climate.

Most modern cooling systems are built to maintain a temperature of 85-100⁰C. If an engine gets too hot, internal engine components can expand, melt and seize, causing a very expensive repair bill. Fortunately, modern vehicles have a clever cooling system that uses cooling liquid and a series of pumps, hoses, thermostats and fans to keep the temperature in check.

The engine’s cooling system is pressurised by the radiator pressure cap. This raises the boiling point so the engine can operate at higher temperatures. Combining water with engine coolant – also known as antifreeze – allows the engine to operate at wide range of temperatures; anything from freezing cold to very warm summer days.

The coolant’s secondary function is to act as an inhibitor that protects internal parts of the cooling system from corrosion. Over time, the aluminium, plastic, rubber and steel parts within the system can suffer if tap water or weak, older coolant is used. Depending on the manufacturer, engine coolant can last from 30,000km up to 100,000km. If a cooling system is poorly maintained, corrosion will begin to form inside the system, leaving you totally unaware of what’s really going on inside the engine. That’s why testing the strength of the cooling system is vital during vehicle servicing as it’s often not until you notice a leak that you find out something might be wrong.

You’ve probably seen an ad on TV or even a car broken down on the side of the road with steam coming out from under the bonnet. This happens when a cooling system overheats and once the cooling system fluid hits the atmosphere it instantly boils and turns to steam, just like an unground geyser. The coolant is dangerously hot and people can receive serious burns from just removing the radiator cap when the engine is hot. Unless you know what you’re doing, never remove a radiator pressure cap until the engine has completely cooled down.

If you’re constantly topping up your radiator reservoir, we’d recommend getting your vehicle checked by a professional. If you also notice a puddle of coolant on the ground every time you park or the temperature needle is no longer happily sitting where it used to, get it checked to avoid journey disruptions and a roadside rescue.

Regular vehicle servicing and maintenance can help minimise the potential for problems in the future. After all, you don’t want to be left at the side of the road just a few kms into your summer road trip.