Automotive Tips and Info

What do I pour in my cooling system?

This is becoming a common question these days. Automakers have added a variety of different coolants/antifreeze in their late model vehicles. This is where your owners manual will be a valuable asset to your car.

The newer vehicles cooling systems, consisting of the engine, radiator, heater core, and hoses have changed a lot. The effort to achieve the best heat transfer or cooling has manufacturers using a lot of aluminum. Most radiators and heater cores are aluminum and many of the engines have aluminum cylinder heads along with the engine block itself being aluminum. The coolant in these systems has to change to meet the needs of the newly designed parts.  The color is the first thing that we will notice. All coolant is dyed to achieve the desired color.

Green is the most common that were accustomed to seeing. It was recommended to change the coolant in these vehicles every two years to keep the cooling system protected.  It has been found that drain intervals of this coolant can be increased if the system has the pH level and the freeze point tested on a regular basis.

Since the mid 90’s General Motors started using a different formula. The orange coolant, known as long life, extended life, or Dexcool has different chemicals added to it to achieve the long life status. It is stated that if the cooling system is kept free of contaminants that the service life is 5 years or 150,000 miles. The key to this FREE OF CONTAMINANTS. This means the cooling system needs to have any leak repaired quickly before any other fluid is added to the system. If any water is added then this will deplete the additive package and the long life has status has been shortened.

GO 5 is the latest to join the passenger car and light truck coolant category. The color of this coolant has been dyed yellow. It also is a long life coolant that needs to be handled the same as the Dexcool. The GO 5 coolant is used in later model Ford and Chrysler vehicles.

In my opinion it is best to use distilled water to dilute the coolants to a 50% to a 70% mixture. The use of distilled water and not ordinary tap water will prevent the scale and corrosion to form caused by the hard water. One thing to keep in mind is that in pinch it is not going to hurt the cooling system to add tap water, it is better to use something that can be flushed out than overheat the engine.

- Jeff Powers