How to Determine When to Replace the Coolant
2 Answers
To determine when to replace the coolant, look for the following signs: the coolant changes color, the liquid level is not within the standard range, or it has been more than 3 years since the last replacement. Locate the coolant reservoir in the engine compartment, which has two English markings: 'max' and 'min.' 'Max' represents the maximum level, and 'min' represents the minimum level. Do not mix coolants of different brands and models, as the different chemical compositions may render the coolant ineffective. The functions of coolant are: 1. Preventing freezing when the vehicle is not running—liquid turning into solid expands in volume, which can crack the engine block; 2. Cooling the engine after the vehicle starts, preventing the engine from overheating and causing damage. Coolant also prevents rust and excessive scale buildup, which can clog the pipes.
As a seasoned driver with over a decade of experience, I’d like to share a simple method to determine if your coolant needs replacement. During every maintenance check, I pop open the hood and inspect the fluid color in the coolant reservoir. Fresh coolant in new cars is typically bright green or pink and very clear. If it appears cloudy, darkened, or has floating debris, it’s likely aged and due for a change. I also dip a finger in to feel the texture—if it’s gritty or sticky, the additives have degraded, raising corrosion risks in the system. Personally, I replace mine every two years or 50,000 km, as anti-corrosion agents break down over time. Delaying this can lead to higher engine temperatures, rust in the water pump or radiator. A strong odor from the engine bay in summer is another red flag. I recommend keeping a refractometer to test boiling/freezing points—if readings fall below specs, head straight to the shop. It’s not worth cutting corners here.
