What is coolant?

Coolant is a liquid mixture composed mainly of distilled water and chemicals (either ethylene glycol or propylene glycol). There is a small percentage of additional elements including corrosion inhibitors, antifoams, dyes and other additives – which distinguish one coolant from another. It is used in vehicles to maintain the engine’s ideal operating temperature and prevent the radiator from overheating. Coolant regulates the temperature of a vehicle’s engine by absorbing the intense heat generated by a running engine, in addition to protecting the engine’s components against corrosion. It can also contain antifreeze to prevent the engine from freezing in very cold climates. Coolant changes the freezing and boiling points of water; raising the boiling point of the cooling system in summer and lowering the freezing point in winter. An ideal coolant has high thermal capacity, low viscosity, is non-toxic and chemically stable. There are three main types of coolant that car companies use; Inorganic Additive Technology (IAT), Organic Acid Technology (OAT), and Hybrid Organic Acid Technology (HOAT).

How does the cooling system work?

Only about one third of the total heat produced during combustion from the engine is converted into energy to propel the vehicle forward. The cooling system removes approximately a third of the engine’s heat by circulating coolant through the engine. The remaining excess third is removed by the exhaust systems. A pressurised radiator cap raises the boiling point of the coolant, while the overflow bottle lets the coolant expand when it’s hot, and the cooling fan provides air flow through the radiator when the car is idling.

How to check your engine’s coolant level

Coolant is just as important to check & maintain as oil is to your car. Coolant requires changing because the chemicals in the coolant break down and become less effective over time. This ends up producing rust and sludge, which can cause damage to the cooling system. If the cooling system becomes damaged, it can result in the engine overheating, which is a costly repair. A regular visual check of the coolant level in the overflow bottle should be sufficient in between services to determine if the level is satisfactory. If the level is low and you need to top it up, or if your car is overheated, never remove the cap of a hot radiator. The radiator cap is pressurised and opening it while hot causes a spray of hot steam & coolant, which can result in serious burns. Ideally, wait a couple of hours with the bonnet up & then carefully & slowly open the radiator using a rag or towel. The different colours of coolants indicate different chemical compositions. Mixing different colours together can compromise the performance of your vehicle. Always consult your vehicle’s user manual to determine the correct coolant for your vehicle.

How to tell if there is a problem

If you find you are having to top up the coolant level frequently, and/or you notice a puddle under the car, it is a sign there may be a leak. An external leak is easier to fix than an internal leak, however both require a visit to your mechanic before further problems occur. Another sign there is an issue with the cooling system is the car running hotter than normal. In this case the temperature gauge will rise above its normal range; usually activating a warning light. If this occurs, it is important to stop the vehicle somewhere safe and call your mechanic. During Summer, we see a lot of busted radiators. If you notice a problem, need help checking or topping up your coolant, or are due for a service; contact one of the friendly team at Burleigh’s Mobile Mechanic on 0412 161 776. We will check your cooling system and have you back on the road safely in no time! Don’t forget to like our Facebook page for helpful information, tips and special offers.