5 Tips to Keep Your Jeep Running Cool this Summer

It’s essential to understand the basics of your Jeep’s cooling system. While there are minor variations between engine configurations and generations, all platforms share the same basic components. These include: 

• Radiator

• Radiator cap

• Coolant (Antifreeze)

• Coolant overflow tank

• Coolant hoses

• Thermostat

• Water pump

• Heater core

• Heater hoses

You should also know that internal combustion engines produce an exceptional amount of heat during operation. If left unchecked, engine temperatures would reach well above the safe threshold of approximately 200º F, resulting in catastrophic engine damage.

Fortunately, modern vehicles are fitted with liquid cooling systems to combat excessively high temperatures. These systems serve three key roles: allowing the engine to quickly reach operating temperature, maintaining proper operating temperature (195–200º F), and extracting excess heat from the engine. But how does the cooling system work? 

To keep things simple, let’s discuss the elementary components of your Jeep's cooling system, beginning with the water pump. This belt, chain, or gear-driven pump kicks on when you start your Jeep, which initiates coolant circulating through the engine’s internals. 

Once coolant within the engine reaches your Jeep’s desired operating temperature, the thermostat opens, thus allowing cold coolant in the radiator to circulate through the engine, drawing out heat as it travels. The hot coolant from the engine then flows into and through the radiator, which uses airflow to cool the once-hot antifreeze before it’s returned to the engine, and the cycle continues! 

This constant coolant flow through the system continually extracts heat from the engine block and cylinder heads, thus allowing your Jeep to maintain a steady operating temperature. 

Maintaining proper engine temperature is critical to your Jeep, which is why it’s constantly monitored on your OEM cluster guage or on any aftermarket Jeep engine monitor. 

Other cooling system components include the heater core and hoses, which use warm coolant from the engine to heat incoming air into the cabin with the heater on. Most cooling systems also employ a spring-loaded radiator cap which vents excess pressure into the coolant overflow tank. 

Now that you understand the basics of the cooling system, you can use these five tips to prevent leaks and accidents that will leave your Jeep’s engine vulnerable to damage.

5 Tips to Keep Your Jeep Running Cool

Inspect for External Leaks

Before digging into your Jeep’s cooling system, it’s best to check for any external leaks, as this is one of the first indicators of an issue. Check your driveway or garage floor for sweet-smelling puddles, which may range from electric green to orange, depending on your year. 

Even if you haven’t noticed any sweet-smelling drips beneath your Jeep, that's not to say it’s leak free! Coolant, composed primarily of water, evaporates when exposed to hot metals like your exhaust, engine block, and cylinder heads. However, unlike water, it tends to leave a crystalized residue when it dries. So inspect areas around coolant hoses, heater hoses, radiator, water pump, and thermostat housing for any visible signs of leakage.

Inspect the Radiator and Heater Hoses

While pliable and heat-resistant, rubber has an expiration date. After years of use, the compound can degrade and swell, resulting in cracks, tears, and leaks. 

Before gearing up for the Summer, check your Jeep’s hoses for signs of excessive wear.

Inspect Your Jeep’s Coolant

While antifreeze has a significantly longer service life than some of your Jeep’s other fluids, it still requires routine replacements every 3–5 years. Prolonged coolant flushes can result in corrosion in the cooling system, excess wear on the water pump, a clogged radiator/heater core, and overall reduced efficiency. 

Before taking your Jeep out this Summer, check the condition of the coolant. Depending on your year and type of coolant, it should be a vibrant green or semi-transparent orange. A murky appearance, especially coupled with a brown hue, is a surefire indicator that your cooling system is due for a flush.

Inspect Your Jeep’s Serpentine Belt

Well, technically, only some Jeeps come with serpentine belts; others, like early YJ Wranglers, came with V-belts from the factory. Regardless, a worn drive belt can seriously hinder your Jeep’s cooling system performance. 

When belts age, they tend to dry out and crack, which causes them to slip across the water pump and fan clutch pulleys. As a result, your Jeep’s water pump and fan spin slower, resulting in reduced efficiency. Additionally, an aging belt poses a risk of breaking on the road, which can simultaneously cut power to the power steering pump, alternator, and other essential accessories. 

Before hitting the road, it’s always best to monitor the condition of your Jeep’s serpentine and V-belts. If cracked, slipping, or squealing, replace them!

Monitor Your Jeep’s Operating Temperature

A tell-tale sign of cooling system woes is abnormal temperature readings, typically resulting in overheating or taking too long to reach operating temperatures. Overheating can stem from multiple causes, including: 

• Low coolant (resulting from an internal/external leak) 

• Failed water pump

• Failed fan clutch/electric fans

• Failed thermostat (closed)

• Internal failure (failed head gaskets/cracked cylinder head)

At the opposite end of the spectrum is an engine that takes too long to reach normal operating temperatures. Generally, this condition results from a thermostat failing in the open position, which allows coolant to circulate through the engine before it can reach proper operating temperatures. In either case, a failed thermostat or water pump is typically caused by a poorly maintained cooling system. 

Now that you have a basic understanding of your Jeep’s cooling system and how to take care of it, you’re ready to hit the trails this summer and put the pedal to the floor.