Engine cooling: maintenance tips for your car’s cooling system

Arif/Jul 29, 2020 11:00 AM

A heatstroke can cause escalate your pulse, make you dizzy, and can be fatal. It takes 1 hour of sitting in a closed hot car (parked under the sun) to kill an adult human being. Just like us, car engines too can be severely damaged if operated in overheated conditions.

The engine can warp, swell, expand, or even crack in case of overheating. Overheating is bad for both human beings and engines. To keep engines cool, cars are equipped with a cooling system. In this article we will share some easy maintenance tips to keep your cooling system in check.

Cars with heaters have the heating system joined with the engine cooling system. Photo: cars.com

The cooling system of a car engine operates on the very simple concept of heat transfer. The concept of heat transfer can also be found in air conditioning systems, refrigerators, or even a water-cooled gaming PC. To keep your cooling system in check, let’s go through the components of the system.

Major components of the cooling system are:

  • Coolant
  • Water Pump
  • Radiator
  • Radiator fan (includes relay and thermostat)

Let’s go through them one by one so we can understand how they work and know how lookout for problems. We’ll start with the easy ones first.

1. Coolant liquid

Pop the hood and one of things you’ll notice is a little cap with warning to not open it while it’s hot. Do not open it when it is hot. This is the radiator cap. Besides the radiator cap, you might also notice the radiator reserve tank too. These are filled with coolant liquid. The coolant draws heat away from the engine, gets cooled down by the radiator and is then circulated back into the engine.

How long are coolant change intervals?

For the Perodua Bezza, 40,000 km or 24 months. It depends on your car model but that’s generally the time period for radiator coolant changes.

What can go wrong with coolant liquid?

The coolant can become more acidic and become corrosive if left unserviced. Since the coolant moves throughout the whole cooling system, neglecting this would further corrode the radiator, water pump, thermostat, radiator cap, hoses and other parts of the cooling system. A coolant liquid that has turned brown indicates rust in the cooling system.

Coolants can also leak. Obvious leaks are usually visible to the naked eye, but you can also pay attention to the coolant levels in the radiator reserve tank to detect irregular drop in coolant levels.

2. Water Pump

Water pumps are what make the coolant circulate in the engine. Water pumps are usually belt driven but some modern cars of today are equipped with electric water pumps. You might have heard the mechanic recommend you change the water pump when going for a timing belt replacement. That's about the correct interval for it. Water pumps are consumables which means you just replace them with a new one at the recommended intervals

Water pumps impellers can rust and corrode. Photo source

What can go wrong with water pumps?

Inside the water pump is an impeller that can be either plastic or metal. If it’s plastic, it can break. If it’s metal in can corrode until there are no blades left. Water pump bearings may also go bad and emit a grinding sound with the occasional screeches. If you detect signs of a bad water pump, change it. Water pumps are consumables.

3. Radiator

The radiator is where the hot coolant liquid gets cooled down. The radiator is made of multiple tiny fins that increase the surface area for heat transfer.

What can go wrong with radiators?

A cracked radiator

They can crack, clog, or leak. Cracks and leaks can be detected visually. To detect a clog, you will need to do a drain test and see how fast the radiator is drained out with the drain plug removed. Slow draining of the coolant indicates a clogged radiator.

4. Radiator Fan

A motorized radiator fan

Radiator fans blow air onto the radiator. Some longitudinal engines have belt driven radiator fans which have their own set of problems. Most cars in Malaysia are front-wheel-drive and have transverse engine configurations. Hence our radiator fans are usually motorized.

Some longitudinal engines are equipped with belt-driven fans. Photo: liveabout.com

What can go wrong with radiator fans?

The electric motor can fail and the fan can stop spinning. This means air is no longer blown onto the radiator. If your car uses one fan for both the radiator and the air-conditioning system, you may be able to detect this problem when the air-conditioning no longer blows cold air.

The Perodua Bezza does not have a water temperature gauge. Only a light to show if the engine is too cool or too hot. That's a thumbs down from me.

Other than that, you may also notice a spike in water temperature if the fan fails. In the event of a spike in water temperature, immediately shut off the engine to avoid further damage.

The Proton Persona's gauge cluster has a water temperature gauge. Photo: kensomuse

One annoying thing that can happen is to have the radiator fan relay or thermostat fail. These are the components that control whether the radiator fan is turned on or turned off. When these components fail, the radiator fan will not turn on when it needs to. Always replace these items with genuine parts to ensure a safe driving experience.

A cracked engine head. Photo: enginebuildermag.com

In summary, those are the 4 major components of the engine cooling system that you can monitor yourself. Always consult an expert before you decide to DIY anything. You can also check the hoses for damages or leaks. If you plan to travel far, make sure to have your cooling system in check. If in doubt, turn off the engine and consult an expert. Damaging your engine because of a failed cooling system is not a great experience.