Coolant is the fluid that captures heat produced by the engine and disposes of it through the radiator. The heat is also dispersed through the heat exchanger in the passenger compartment when you turn on your heater in cold weather. Coolant, normally referred to as antifreeze, is a 50/50 combination of ethylene or propylene glycol and water. Servicing the coolant is a two-step process of draining and/or flushing the vehicle’s cooling system and replenishing what was emptied with a fresh supply.
Should this service be performed at recommended intervals?
Yes, because swapping the old coolant for new rids the cooling system of soot that can clog it up and create issues with heating and cooling in the winter and summer months.
Why is it necessary to change the coolant?
Since coolant operates in an environment where extreme heat is a factor, it naturally breaks down as time passes. Furthermore, the coolant’s rust inhibitors become depleted, leaving the tiny cooling passages of your engine and radiator susceptible to corrosion. Despite the presence of rust inhibitors, corrosion is likely to occur with age. In turn, the coolant will become polluted with rust particles and other debris.
What happens if I stop changing the coolant for a lengthy amount of time?
If the rust inhibitors fail, the interior of the cooling system will begin to deteriorate until the exterior rusts out as well. The biggest contributor of rust in a vehicle’s cooling system is the engine block. As time goes by, rust bits will also cause an obstruction to the small passages inside the radiator and heater. Eventually, this buildup will cause the engine to overheat. When this happens, you can be sure you’ll have to pay a mechanic a large chunk of change to restore your vehicle.
Is there any upkeep that may be necessary between scheduled coolant maintenance?
You should check your coolant level according to the stated interval in your owner’s manual. If the engine temperature is cold when you check the coolant level, the coolant should be even with or above the “minimum” line on the clear refill container. If you check the coolant when the engine is hot, it should be no higher than the “maximum” fill line.
If you notice the coolant seems to have disappeared, this could be caused by an external or internal leak. An internal leak is more expensive to repair, but either one should be fixed as quickly as possible because operating on little to no coolant can result in cataclysmic engine failure and an even larger cost to fix the problem.
If you live in a climate where the temperature often drops below freezing, request that your mechanic checks the concentration of coolant. Watered down or weakened coolant may have the ability to freeze if the temperature falls below 32°F.
Consult your owner’s manual to find out if your vehicle uses “long-life” coolant. If so, the only maintenance your car should require is checking the coolant level to verify whether coolant is leaking or burning.
Quick tip
Antifreeze has a smell and taste that appeals to household pets. A mere half teaspoon is capable of killing an average-sized cat, and eight ounces will kill a 75-pound dog. There is nothing that can be added to antifreeze to decrease its appeal to animals, but antifreeze made with propylene glycol, as opposed to ethylene glycol, is about 67 percent less toxic. Look for the brands Sierra, Prestone Low Tox, and Texaco PG for safer antifreeze.