NAPA AUTOPRO

Does my car need a coolant flush? 

Did you know that the combustion chamber of modern engines reaches temperatures upwards of 4,000°F 2,200°C? That’s not a typo. The metaphorical eggs we cook in the heat of the summer on our car would incinerate in an instant. To keep the engine cool, you need coolant. So don’t overlook this important fluid in your gas-powered car. 

How does engine coolant work? 

Engine coolant is a mix of water and antifreeze that maintains your engine’s temperature. The ratio is usually 50/50, but in extreme hot and cold climates, you may find mixtures of 70/30 antifreeze to water. 

The coolant circulates around the engine to both keep it cool and warm it up, depending on the engine’s needs. In the summer, when temperatures are high, coolant brings those soaring internal temperatures down. 

In cooler weather, especially when outside temperatures reach below freezing, the circulating coolant actually helps warm up your engine so the oil doesn’t become viscous and damage engine parts. 

The coolant thermostat dictates how coolant is used to provide optimal engine performance. 

Maintaining optimal engine coolant levels 

To maintain your coolant on your own between coolant flushes, monitor for these three symptoms every six months: 

  1. Your coolant reservoir will have a mark that shows how much coolant you need to support your engine’s performance. Is your coolant below this mark? 
  2. Does your coolant look milky? 
  3. Do you see debris floating in the reservoir? 

If your coolant level is low, top it up, but don’t overfill it. Also ensure that you don’t mix coolants. Mixing coolants can cause them to gel, which can block the flow of coolant through the engine and eventually cause your engine to overheat. If you don’t know what coolant to use, talk to your automotive technician at a NAPA AUTOPRO service centre

If you find yourself frequently topping up your coolant, you may have a coolant leak. Take your vehicle to a service centre for a proper inspection. 

However, if your coolant looks milky or you see debris floating in it, you need a coolant flush. Although modern cars may not need a coolant flush for ten years, many manufacturers still recommend one every two to three years. Your owner’s manual will give advice specific to your vehicle, but if your coolant looks contaminated, bring your vehicle in right away. 

What is a coolant flush? 

Flushing out the coolant simply means draining it and replacing it. However, this procedure is not as simple as changing your engine oil, and it should not be done at home. 

Antifreeze contains either ethylene glycol or propylene glycol, plus other additives to help protect your engine by inhibiting corrosion and lubricating components. Additionally, discarded coolant includes debris and heavy metals from your vehicle. Although propylene glycol is considered environmentally friendly, coolant is still toxic to the environment. 

People who work with antifreeze must take extra precautions to prevent it from seeping into the environment, being inhaled, or coming into contact with their skin. Your municipality may also have bylaws against allowing hazardous waste – which may include coolant – into the sewer system. 

Why is a coolant flush necessary? 

Because coolant becomes contaminated over time, you need to flush the engine cooling system completely every few years. Otherwise, you can start a cascade of events: contaminated coolant becomes more viscous, causing it to slow down as it flows through the cooling system. This means less heat transfer away from the engine. Your engine overheats and, in worst-case scenarios, you can have catastrophic engine failure, which requires a full engine replacement. That service costs several thousand dollars. 

Or…you can spend a few hundred dollars having your coolant flushed. 

When you bring your vehicle in for a coolant flush, the technician will also inspect the entire coolant system for damage. This includes not only the tubes and hoses the coolant itself passes through, but also the radiator, coolant reservoir, fan, thermostat, and several smaller parts. You’ll have a happy engine at the end. 

For more information on coolant flushes, or to book one for your vehicle, contact your local NAPA AUTOPRO service centre

Photo: IStock_1456865126