Friday, February 1

Cooling Systems


It’s hot. And you’re stuck in traffic, again. No biggie, just crank up the stereo and the a/c, and wait it out. Creeping along, you start to smell that cloying, unmistakable maple-syrup-in-a-Turkish-bath-smell of boiling coolant. Turning off the air helps for a few minutes. Turning on the heater helps for another few hundred yards, but the inevitable happens: a geyser of evil green coolant erupts from under your hood. It takes an hour
for the engine to cool off and you can pour some water into it. That’s okay - CARiD is here to help. If your car’s cooling system fails, your car will grind to a halt by the side of the road in short order. Two-thirds of the energy in a gallon of gasoline turns to heat inside your engine, and it’s the responsibility of the to remove that heat promptly and efficiently. The entire cooling system is filled with a mixture of ethylene glycol and water, laced with additives to retard corrosion.
This coolant is pumped through passages in the cylinder block and heads by the water pump, which is usually driven by a rubber belt. It then passes through the radiator to dump heat into the air passing through it. The customary 50-50 concentration of coolant has a boiling point well above 212F. Cars have pressurized cooling systems—as high as 16psi—so the boiling point is even higher, as high as 300F. That same 50-50 concentration also won’t freeze until -34F, providing low-temperature protection