This week, as we are heading into Summer here in Perth, I want to discuss the cooling system of the car.

Cooling systems are a really important system in keeping your car running. It does exactly what it says - keeps the engine cool.

If an engine overheats, then it can cause catastrophic engine damage. Probably the most important thing you can do, is get into the habit of checking your temperature gauge while you are driving. For most cars it will sit at around half, but please check with your mechanic about your specific car.

If it starts to get over the halfway mark, you need to pull over as soon as it is safe to do so to help prevent engine damage. Other cars will only have a light which stays blue when cold and turns red when it over heats. If it turns red, you need to stop as soon as it is safe to do so. Other indications that the car is starting to overheat, is the air-conditioning system not working as well as it normally does. If this happens, check your temperature gauge.

Basically - keep checking your temperature gauge!

What are the components that make up a cooling system? Most people will have heard of a radiator, this is always at the front of the engine bay. This holds the coolant.

Off the radiator are the radiator hoses. Connected to these is usually a radiator overflow tank or otherwise known as an expansion tank. This also holds coolant and is usually where you would top the coolant up from.

Other components are the water pump (responsible for pumping the water through the engine) and the thermostat. The thermostat controls the water flow to keep the engine at the correct temperature (so it runs well).

What if one of these components fails or starts leaking? Ideally, you want to be checking your coolant (and oil level) at least once a month. If you notice that your coolant level is low, then it needs to be topped up.

Just like oil, each manufacturer has their own coolant. It is important to put the correct coolant in the cooling system to prevent damage. Long term you cannot put in plain water. Coolant helps prevent corrosion of the engine and cooling system. Think about it: you can't put metal into water without it rusting, so that's what coolant helps prevent. Most car parts places, such as Repco, will be able to sell you the correct coolant for your car already premixed with distilled water.

This is a Toyota Coolant expansion tank. You can see the coolant is pink. The tank is connected to the radiator by a small hose at the top.

This is an overflow bottle from a Nissan. The coolant is green.

This is an overflow bottle on a Volkswagen. Its coolant is also pink, but a different coolant from Toyota.

Here is an expansion tank from a Ford. It is empty at the moment, as we are replacing the water pump. The coolant will be orange.

If the coolant levels are low, it is important to take it into your mechanic to get it checked out. You may not be able to see the coolant on the ground to know that you have a leak, so checking under the bonnet is really important.

When one part of the cooling system goes, you may find that your mechanic recommends replacing all of the components at the same time. This is because the cooling system works under pressure. If there has been a small leak, the system won't have been under full pressure. So then, when it is fixed - and under full pressure -, other leaks tend to pop up. Thus, often it is just safer to replace all parts at once.

The water pump will be the exception to this. It is often situated behind the timing belt (not always though). So, when the timing belt is done, if the water pump doesn't look great - you would replace it at that point.

That is a really brief overview of the cooling system and some cars have additional components, such as oil coolers, but these are the main ones.

If you have any specific questions about your cooling systems or recommendations given to you by your mechanic please don't hesitate to drop me a line, I would love to hear from you. Have a great weekend, Gabbi

The Author, Gabbi is a mum who helps to run a family owned car service workshop in Dianella WA. Gabbi also produces her own blog called Mechanical Mums