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Should you have your coolant checked before the next McHenry summer?

check coolant for McHenry summer
You can see that the coolant in this reservoir is a bit
brown. It's a good idea to have it checked before
the real heat of a McHenry summer sets in. 
Rich had the car in a McHenry area auto repair shop for an oil change and some other work recently. When he came to pick up the car, the auto repair technician pulled the car out front and brought the key into the office/waiting area.

“I took a look in your radiator – it’s all brown in there,” he said. “You probably want to have your radiator flushed soon.”

That’s a very good idea. Most of the time, we think about checking the antifreeze in October or November. But, this time of year, we tend to refer to antifreeze by its other name – coolant – and it’s a good idea to have it checked before the weather gets too hot.

When the coolant is all brown, there’s a good chance that it won’t work to its intended capacity. As antifreeze, it should be good to 34 degrees below zero Fahrenheit (-37 degrees Celsius). As coolant, it should be good to 265 degrees Fahrenheit (129 degrees Celsius). But, it’s the same liquid. Coolant is antifreeze and antifreeze is coolant. That means that the temperatures above indicate the range of temperatures the liquid can tolerate and continue to perform its intended duty.

Of course, here in McHenry, from the middle of May to the middle of September, we probably won’t see too many days where the temperature falls below zero, no less below 34 degrees below zero. In other words, its capacity as antifreeze isn’t a major concern. But, with temperatures that may reach 100 degrees Fahrenheit, the operating temperature could test the bounds of 265 degrees Fahrenheit.

If you coolant is brown, that’s a good indication that it may have lost its tolerance for extreme temperatures. Even if it isn’t brown, you should have it checked. It could lose its mojo while keeping its color.

Check the thermostat, too!!!


The thermostat in the engine’s cooling system is not a mechanical thermometer. It does more than measure the temperature of the coolant antifreeze; it also opens and closes based on that temperature.

The thermostat will remain closed, stopping the coolant from going through the radiator until the temperature of the coolant is up to operating temperature. And, when the coolant exceeds its best operating temperature, the thermostat will open to allow the coolant to flow through the radiator and cool in the process.

There are even thermostats designed for warmer weather and colder weather. One designed to operate in warmer weather will open at a lower temperature. One designed to operate in colder weather will remain closed longer.

Also check you belts and hoses!!!


The hoses that carry the coolant antifreeze from the engine to the radiator and the heater core are made of rubber. Over time, they wear out. If they wear out while you’re driving, you’ll lose the coolant antifreeze from your cooling system and you’ll find yourself on the side of the road.

The belt at the front of your car’s engine turns the alternator and the power steering (sometimes a separate belt). But, it also turns the water pump. The water pump is a pump inside the engine that moves the coolant through the cooling system. If it stops turning, which will happen if the belt breaks, the coolant won’t move and your car will either overheat or stop running because the alternator isn’t providing the electricity it needs to operate. In either case, you don’t want to lose your belt.

McHenry is a great place to be in summer – warm but usually not as hot as the deep South. But, it’s a pain if your coolant isn’t doing its job.




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