INFINITI Cooling System Guide: How Your INFINITI Keeps Its Cool

December 2, 2021

When it comes to engine performance, heat is your worst enemy. Excessive heat breaks down vital engine components and can leave you with a massive repair bill. Thankfully, if everything is working as it should under the hood, your engine cooling system will help keep your INFINITI running smoothly. Keep reading to learn how your INFINITI's cooling system works, how long you can run an engine without coolant, how to make an engine run cooler, and more.

Parts of an Engine Cooling System

Your INFINITI's heating system features many components, and when it fails, you could have more than just low coolant levels to blame. What are the different parts of the cooling system, and what do they do?

Coolant

Coolant, as the name suggests, is the fluid responsible for keeping your engine cool. Engine coolant acts as a heat exchanger by absorbing heat generated during combustion and transferring it away from the engine block. This is essential to keeping your engine at optimal operating temperatures.

Coolant is made up of a mixture of distilled water and antifreeze. While water acts as the primary heat exchanger, the ethylene glycol (sometimes propylene glycol) in antifreeze minimizes corrosion on engine parts. It also raises the coolant's boiling point and lowers its freezing point. The proper ratio of water to antifreeze in your vehicle's coolant will depend on the climate you're driving in, though a 50/50 ratio is standard.

In extremely hot or cold climates, your car will likely need a higher ratio of antifreeze to keep the coolant from boiling or freezing and inadvertently damaging your engine.

Radiator

The radiator sits at the front of your vehicle, just behind the grille. Its purpose is to cool down hot coolant coming from the engine block. Radiators work by pushing hot coolant through thin tubes with cooling fins attached. Air flows over the radiator's cooling fins and between its tubes while you drive, taking heat from the coolant with it.

Radiator Fan

Right behind the radiator is the radiator fan. If there is not enough air flowing through your car's grille while driving, the fan activates to draw more air through the radiator.

Pressure Cap

The pressure cap, also known as the radiator cap, is a pressure-regulating valve at the top of the radiator. It helps maintain the necessary pressure in the cooling system to raise the boiling point of the coolant. If the pressure from hot coolant entering the radiator is too great, the pressure cap diverts coolant into an overflow tank so the remaining coolant can flow into the upper radiator.

Water Pump

The water pump powers the circulation of coolant throughout the cooling system. It is driven by an engine belt and pumps cooled-down coolant from the radiator back into the engine block.

Thermostat

The thermostat maintains the engine's operating temperature by regulating the flow of coolant into the radiator. When coolant flowing around the engine gets too hot to effectively cool the engine, usually around 200°F, the thermostat opens so the hot coolant can be sent to the radiator for cooling. While the thermostat is closed, coolant is sent back through a secondary hose to the water pump, where it is recirculated through the engine block until it becomes hot enough to open the thermostat.

Heater Core

Toward the back of the cooling system, just behind your car's dashboard, is the heater core. The heater core is what sends warm air into the cabin of your car when you have the heat turned on.

When you switch on the heat inside your car, hot coolant is diverted through a bypass hose to the heater core. Air blown over the heater core by a motorized fan absorbs the heat and transfers it through the vents of the passenger cabin to warm the inside of your car. If you have an overheated engine, turning the heat to full blast in the passenger compartment will help cool it down.

How Does a Car Cooling System Work?

Most cars on the road these days use liquid cooling systems to keep the engine working at optimal temperatures. Coolant is necessary because internal combustion engines are actually quite inefficient. Even the best engines are only about 15% efficient at turning fuel into power, and the other 85% of engine power is lost as heat. Though some of this heat is released through the exhaust system, it is the cooling system that does most of the work to help keep your INFINITI's engine from overheating.

Here's a step-by-step process for how a cooling system works:

1. When you start your engine, the water pump immediately begins pumping coolant from the lower radiator tank into the coolant passages surrounding the engine cylinders.
2. Coolant flows first to the engine block and then to the cylinder head, absorbing heat along the way to the radiator outlet hose.
3. The coolant continues to circulate around the engine until it becomes hot enough to open the thermostat. If the heater is turned on, hot coolant will first flow to the heater core to warm up the passenger cabin before being sent back to the water pump via a bypass hose.
4. When the thermostat opens, hot coolant flows through the radiator hose into the upper radiator tank. A thermostatic switch activates the radiator fan.
5. Hot coolant flows from the upper radiator tank through the radiator's tubes, where it is cooled by airflow over the radiator's cooling fins. If the incoming coolant is too hot and pressurized, the radiator cap opens to divert some of the coolant into an overflow tank, thereby decreasing pressure in the radiator.
6. When the coolant reaches the lower radiator tank, it is cooled off enough to begin circulating around the engine once again.

How to Tell If There's a Problem with Your Cooling System

With proper maintenance, liquid cooling systems can help keep your engine running smoothly for a long time. It helps to visually inspect cooling system parts and check coolant levels regularly to make sure everything is working as it should. Still, it's not uncommon to experience problems with your cooling system when parts inevitably get damaged or wear out. Watch out for these signs that may indicate your cooling system has a problem:

• Your car is frequently overheating
• The engine coolant temperature gauge is running hot or fluctuating
• Coolant in the reservoir is constantly running low
• Leaking coolant (greasy yellow, pink, or green liquid) is visible under your vehicle
• Steam or smoke is coming from under the hood
• White exhaust smoke
• A noticeable decrease in gas mileage

These symptoms can be caused by any number of problems with your cooling system, from a small leak to a damaged component. Here are some of the most common causes of cooling system failure:

• Radiator leaks
• Clogged radiator
• Low coolant levels
• Contaminated coolant
• Burning coolant
• Failing water pump
• Faulty thermostat
• Broken radiator cap

Careful: If you notice steam coming from under the hood of your car, you likely have a busted radiator cap. Turn off your car and allow the engine to cool at least 30 minutes before attempting to open the hood. If steam or hot coolant is coming from the radiator cap, do not open it unless the engine has cooled down completely. Opening the radiator cap while the engine is still hot puts you at risk of serious injury from scalding, pressurized coolant.

If you suspect your vehicle has a cooling system problem, the best thing you can do is have it inspected by a trained technician at your nearest INFINITI service center.

How Long Can You Run an Engine Without Coolant?

The short answer is not long. Your engine depends on coolant to properly function and would likely overheat in a matter of minutes without it. Without coolant to extract heat from the engine, you risk a serious and expensive breakdown of engine components.

How to Make an Engine Run Cooler

Heat is the biggest threat to a well-functioning engine. If your cooling system isn't up to par, consider replacing parts that aren't working as well as they should. Whether an old cooling system part has worn out or you'd like to increase the efficiency of a component, sometimes the simplest solution is to replace a part with something better. Upgrading to a more efficient radiator, water pump, or radiator fan are common ways to help keep your engine cooler. Cooling system can't stand the heat? Shop genuine INFINITI cooling system replacement parts from INFINITI Parts. Find the parts you need online and visit your nearest service center for professional installation.