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05.08.2019

When Should You Replace Coolant in Your Subaru WRX? Perth Expert Advice

City Subaru - Subaru WRX

When they own a Subaru WRX, Perth petrol heads have one of the best performance saloon cars available on the market. The Subaru WRX has an excellent engine, but like any modern technologically advanced power plant it requires coolant. Sadly, some drivers neglect their engines coolant needs, and this can impact performance. Let’s take a closer look at engine coolant and examine when it should be replaced.

What is Engine Coolant?

Modern engine coolant is now sourced from a plastic bottle rather than a tap. Simple water will not cut it as a coolant anymore because many modern engines have an alloy head. Engine coolant is usually mixed with propylene glycol, which can lower the freezing point of the solution to -37º and raise the boiling point to 129º if a pressurised cooling jacket is used.

How Important is Engine Cooling?

When two different metals come into contact with each other, galvanic corrosion can occur. Even is these metals are separated by a rubber gasket they can still corrode when they are in proximity to one another. Over time, engine coolant circulating through the engine will pick up metal particles from the cooling jacket and distribute them throughout the entire engine. When this “plaque” is carried in the coolant the anti-boil and antifreeze properties are diminished. This is why it’s vital to secure the long term durability of the engine by flushing out the engine coolant and replacing it in accordance with the manufacturer’s recommendations.

How Does Corrosion Affect Engine Cooling?

A buildup of corrosion in the cooling jacket will restrict the engine coolant flow. This could increase pressure inside the cooling jacket and place additional stress on the radiator hoses. This will reduce the ability of the WRX cooling system to remove heat from the engine. This will make the engine run hotter than it should, the thermal management will suffer, and the fuel combustion will be far less efficient. If a radiator bursts under this sort of pressure the cooling system contents could be discharged entirely and the engine may overheat catastrophically before the driver notices. When overheating occurs, the alloy head will warp, it will then lift off the engine block, and all the cylinders will lose compression. This is expensive to repair, the cylinder head will need to be removed, machined and refitted, the valves and pistons may be damaged, and the gasket will need to be replaced.

How Often Should Engine Coolant be Changed?

Every car manufacturer will have guidelines on how often the engine coolant should be checked, topped up and changed entirely. The service technicians will check you Subaru WRX as part of your regularly scheduled servicing. If the engine coolant needs to be flushed and replaced they will do this for you. But, it’s essential to maintain the coolant level between the servicing visits to maintain optimal engine cooling.

If you are looking to buy Subaru WRX cars, get in touch with Perth City Subaru to arrange a no obligation test drive.