How Often Should the Coolant in a Car Be Replaced?
2 Answers
Vehicle coolant generally needs to be replaced every 2 years or 40,000 kilometers. This is just a reference interval. For commercial vehicles with higher mileage, the replacement cycle should be shorter. Since driving conditions vary for each car, the replacement should be based on actual usage. Check the coolant level regularly; if it is insufficient, top it up promptly. If suspended particles, sediment, or signs of deterioration or discoloration are found in the coolant, replace it immediately and clean the system. Coolant Replacement Method: Before completely replacing the coolant, conduct a thorough inspection to check for any leaks or cracks in the pipes, with a focus on the five-way hose. The five-way hose is named for its five connection points that distribute coolant to different parts of the car. If there are any signs of coolant leakage in this area, replace the hose or reseal the connections as needed. Drain the old coolant and flush the system with clean water. Add water to the coolant reservoir and continue filling until water flows continuously through the engine cooling system. Then, start the engine and let it idle for 3 to 5 minutes to circulate the water. Initially, the water draining from the reservoir may appear slightly pink. Continue flushing until the water runs clear. Remember to remove the heater hose and drain the water from the heater core. After draining for about an hour, add the new coolant through the radiator hose to allow it to flow quickly into the radiator. Then, fill the coolant reservoir with another bottle of coolant until it is nearly full. Start the engine and let it run for about 10 minutes. As some air is expelled from the cooling system, the coolant level will drop. Top up the coolant to the "MAX" mark on the reservoir.
Last time I heard from the repair shop technician that coolant isn’t like mineral water that you can keep using forever. My Honda, after four years and 60,000 kilometers, was recommended for a coolant change during maintenance. This stuff mainly prevents freezing, boiling, and rust, but the additives inside gradually lose effectiveness. Friends in the south might get away with changing it every two years, but for us in the northeast where it drops to -20°C, it’s best to strictly follow the maintenance manual. If the freezing point isn’t sufficient, the radiator can actually freeze and crack. During regular car washes, take a quick glance at the overflow tank—if the fluid level is below the minimum mark or the color turns rusty, don’t hesitate, drive straight in for a check. Last time, my neighbor Old Wang tried to save money and didn’t change it for three years, only to end up with the temperature gauge hitting red on the highway—the towing fee alone cost ten times more than a coolant replacement.
