Auto Repair Q&A



Cooling System










Auto Repair Products

Servicing Your Cooling System for Winter

Radiator hose

Believe it or not, the best time to service your engine's cooling system, especially if you live in a cold environment, is in the fall rather than the spring. Traditionally, springtime is when most think about their engine's cooling system, but the winter is when it's most likely to have issues due to anti-freeze breakdown or leaks. This is because in the winter, your engine's coolant spends more time "sitting" rather than circulating and is more likely to be subjected to temperature extremes.

An efficient cooling system requires:

  • An adequate supply of coolant.
  • An efficient heat exchange
  • An operating radiator fan.
  • An efficient water pump.
  • And a properly tuned and working thermostat.

If any of these things are not working, the system will likely fail. And soon.

For the winter, the coolant level and mixture and a working thermostat are usually your priorities. Everything on the list above is important, but the most common fail points in winter are the coolant itself and the thermostat.

Know Your Climate

If you live in the extreme cold, you should know the temperatures that are likely to be achieved in your area - both highs and lows. In nothern parts of the United States, for example, overnight lows of -20 degrees Fahrenheit are not uncommon and wind chills that push that number down another 20 degrees are not unheard of.

In those areas, winter mixes of antifreeze are common, with ratings of -20 or -40 or even lower. Your antifreeze will have a freeze rating on its jug. Most common purchases are 0-degree to -20-degree in a 50:50 mix. Many low temperature options have a more antifreeze-biased mixture that uses less water.

Flush and Replace

If your interval is up or you suspect that your antifreeze mixture is not adequate for your climate, flush and replace it. If the weather is already cold, it's recommended that the "flush" be done with antifreeze mix rather than just water. During the flush procedure, checks of the thermostat and hoses are also recommended.

Before the very cold weather comes, be sure to clean your radiator's fins. The jet spray at the car wash, if used with simple soap or just pressurized water - be careful the pressure does not damage the fins - will do the job.

Throughout the Winter Checks

During the season, periodically check your engine's coolant levels as you check other fluid levels. This should be a regular maintenance item you do routinely. Checking fluids weekly is recommended as a part of a thorough vehicle walk-around to look for hazards or problems. Winter checks are very important as added road hazards such as broken snow chains, road sand and salt, and other things can wreak havoc on your vehicle if not noted and taken care of early.