What Goes In the Dex-Cool Tank?

Ideally, traditional green coolant changes color due to corrosion. The color change informs you when to change the coolant inside your engine. However, aluminum engines differ from this. Hence, Dex-Cool coolant is specifically designed for engines with aluminum parts to minimize corrosion. Dex-Cool coolant is an antifreeze in coolants that uses organic technology.

General Motors introduced the ethylene glycol coolant in their 1996 model year vehicles. Its formula is silicate and phosphate-free to extend the coolant’s lifespan. Dex-Cool follows the same approach. Let’s dig deep into the engine coolant.

Engine Coolant Temperature Gauge

The engine coolant temperature gauge is your vehicle’s coolant warning system. It is one of the dials on the dashboard, and from it, you can tell the engine temperature, like whether the engine coolant is cold, normal, or overheating.

Engine Coolant Temperature Gauge

The optimal engine temperature ranges between 195 and 220 degrees. Ideally, the needle on the temperature gauge should point right at the middle. Cold could mean that your vehicle has not warmed up yet. This could be due to cold weather, the presence of an open thermostat, or the gauge being broken. On the other hand, a high read could mean that your vehicle’s engine is overheating. When this happens, avoid opening the radiator pressure cap, and instead, pull over at a suitable place and let the vehicle cool down.

Coolant Surge Tank

A coolant surge tank allows the expansion of the heated coolant from a hot engine without causing the cooling system to fail. It also keeps your vehicle’s cooling system rust-free.

When your car’s engine is running, it needs a coolant to keep it at the optimum temperature. The coolant absorbs heat from the engine causing it to heat up in the radiator. Heat build-up causes the coolant to expand, thus increasing pressure in the vehicle’s hot cooling system. Once the pressure becomes more than what the radiator pressure cap can hold, the coolant overflows past the radiator’s seal, through the overflow tube, and into the coolant surge tank.

Coolant Surge Tank

The coolant will then cool down later when you turn off your vehicle’s engine. The antifreeze then decreases in volume, causing a decline in pressure, which creates a vacuum. The vacuum causes a valve to open in the radiator cap. Once the pressure cap opens, the coolant overflown into the coolant surge tank flows back into the radiator.

If a car does not have a coolant overflow tank, the vacuum created by a decline in pressure in the radiator causes air to be sucked into the radiator in place of the coolant. This eventually leads to the formation of rust in the radiator.

Cooling System

The work of a cooling system is to cool your vehicle’s engine. It has six parts: an engine, a radiator, an engine cooling fan, a water pump, hoses, and a thermostat.

All these parts work together to offer an efficient cooling method. This ensures the vehicle’s engine is operating at an optimal temperature. It also removes excess heat to prevent engine overheating and to heat the engine to its best operating temperature as fast as possible.

Your car generates heat which is transferred to the coolant. The hot coolant moves to the radiator through the hoses in the cooling system. The engine cooling fan then transfers the heat to the air. The coolant is then carried back to the water tank.

Engine Coolant

Engine coolant is a fluid, such as Dex-Cool coolant. The coolant passes through your vehicle’s engine, keeping it at the optimal temperature. The antifreeze fluid keeps the radiator from freezing in low temperatures and protects it from overheating in extreme heat.

Engine Coolant

Engine coolant consists of water freeze and antifreeze mixture. Water is readily available, hence efficient, and antifreeze helps to improve the water’s qualities. It prevents water from freezing in lower temperatures by lowering the freezing point. Coolant also prevents water from boiling by raising its boiling point.

The coolant mixture also contains a rust protection formula that helps prevent the internals of the cooling system from rusting because of water. The coolant mixture can also store heat to heat the inside of your vehicle through a heater matrix and keep you warm.

How Do You Deal With a Hot Engine?

In such an instance, pull over, put your car in park or neutral, and let the hot engine parts, including the coolant surge tank pressure cap and the upper radiator hose, cool down.

How Do You Deal With a Hot Engine

Once the engine parts are no longer hot, use a thick cloth to turn the pressure cap slowly counterclockwise. Steam comes out at high speed and could hurt you; thus, step back and let the pressure build-up release before continuing to turn the pressure cap slowly until you remove it. Using the specific coolant fill procedure, add the proper coolant mixture to the cold fill line, replace and tighten the radiator cap to avoid coolant loss, and engine damage. You can also use drinkable water in place of the coolant in emergencies. However, be sure not to spill coolant on a hot engine as it could burn the engine parts.


Now you know the way to a long engine life. Always check the reservoir tank to ensure proper coolant level before leaving the house. As a reminder, use the vehicle’s specific coolant fill procedure to add coolant to the coolant surge tank. Also, notice the temperature dial to avoid engine overheating and damages. Also, have the engine coolant changed every five years or after 240,000 km – whichever occurs first.

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