A car engine generates a huge amount of heat while running. This heat is generated by the friction from the fast moving parts, as well as the ignition of the fuel and conversion of this fuel to energy.
While heat generation in an engine is inevitable, a build-up or excess of heat can have catastrophic consequences. This means that engine temperature must be closely regulated to prevent engine damage and keep your car running efficiently.
A vehicle’s cooling system is designed to monitor and control engine temperature. The key components include the fan and radiator, coolant tanks, hoses, thermostat and water pump.
How does the cooling system work?
As an engine burns fuel, it creates energy and generates heat, as per the first law of thermodynamics. That heat needs to be vented to prevent damage or excessive wear to the engine. This is the job of the cooling system.
The radiator is essentially a heat exchanger that works to eliminate heat from the engine. When the thermostat detects sufficient engine heat, the coolant is released from the radiator. The coolant is a mix of water and chemicals designed to extract heat and prevent engine corrosion. This mixture is moved through the engine, extracting the excess heat. The heated coolant is then moved back to the radiator, where cool air is moved through the heated mixture, cooling it down and releasing the heat into the air outside the vehicle.
Why cooling is important?
The radiator, and broader cooling system, is an essential vehicle system for a number of reasons.
- Maintaining safe operating temperature
Car engines are designed to operate within a safe temperature range. This safe range will differ for different types of vehicles, with high-performance or air cooled vehicles generally running at higher temperatures.
For standard water cooled engines, the recommended running temperature is somewhere between 80-90℃ depending on the make and model. Within this temperature range, your cooling system thermostat will open, allowing the water/coolant mixture to move through the engine, maintaining a safe operating temperature.
It’s worth noting that running below the recommended operating temperature for prolonged periods of time can also be bad for an engine. If the thermostat is stuck open or there is a problem with the engine coolant temperature sensor or the fan clutch, this could lead to overcooling. An over-cooled car will be less fuel efficient, produce higher emissions and increase the wear and tear on moving parts, as they will be less effectively lubricated.
- Prevent damage and wear
Maintaining the engine temperature within safe operating parameters is vital for preventing engine damage and excessive engine wear. Most car engine tolerances are designed to allow the metals to expand to a certain limited point, depending on the oil and coolant normal operating temperature.
Overheating can damage an engine by expanding the metal outside of these tolerances. This can cause excessive or increased wear and tear on moving parts. It can also lead to major and irreparable damage to the engine.
Signs you’re having radiator problems
There are a number of clear and telltale signs that you are having problems with your radiator or cooling system.
- Leaking coolant
If you find that you are regularly topping up the coolant or noticing coolant drips beneath the radiator, then chances are you have a leak somewhere in your cooling system. This should be fixed immediately.
- Discoloured coolant or sludge
Coolant is usually green or yellowish and has a consistency thicker than water, but thinner than oil. If your coolant is a dark or rusty color or is thick and sludgy, it likely has been contaminated with debris from the engine. Contaminated coolant won’t move through the cooling system as smoothly and won’t cool the engine as efficiently.
- Temperature gauge rising
A car temperature gauge indicates the temperature of the coolant in your vehicle’s engine. If the temperature gauge is rising into the red zone, it means that the cooling system isn’t working properly and that heat is no longer being removed from the engine.
- Overheating, steam or smoke coming from under the bonnet
This one seems obvious, but if you see steam (or what may look like smoke) coming from under the bonnet, it’s a pretty sure sign that there is something wrong. If the smoke is steam-like and accompanied by a sweetish smell, then chances are the coolant is either overheating or leaking. Both are signs there’s something wrong with your cooling system.
- Thumping sounds coming from the engine
Extreme cases of engine overheating can start to warp engine components. This can cause thumping and knocking sounds from under the bonnet. Unfortunately, if you’re hearing this as a result of overheating, chances are you’ve already done some pretty serious engine damage.
If you notice any of these issues, it’s recommended that you get your car to a mechanic as soon as possible.