Chemistry 101: the pH of Your Car's Coolant

We've all been trained by mom, dad and the car's manual to check our coolant level on a regular basis. We may even been good about checking the visual condition and freeze protection level of our coolant. What we haven't been told is that the pH (acidity) of our coolant can be far more important than its specific gravity (freeze level) or visual condition. Now that aluminum heads and engine blocks and other components have become as common as iron under the hood, the addition of an acid, such as automotive coolant that has dropped below 9.0 pH, creates a textbook battery. The resulting transfer of electrons can wreak havoc on your water pump, engine block, cylinder heads, head gaskets, heater core, heater control valve, radiator, hoses and every other metal component. Your ideal pH range is between 9.8 pH and 10.2 pH and a system below 9.0 pH can cause extensive damage in as little as thirty days. Once a cooling system has been neglected and damaged, that damage sometimes cannot be undone. In the shop we use the term "terminally neglected cooling system" to describe a car that has no hope of economical recovery from electrolytic damage. Tom Dwyer Automotive can test your cooling system's pH level and specific gravity free of charge and recommends you perform this test at least once a year.