How often should car coolant be replaced?
2 Answers
The coolant in a vehicle should be replaced every two years. This is just a reference interval. For commercial vehicles with higher mileage, the replacement cycle should be shorter. Since driving conditions vary for each vehicle, the replacement should be based on actual usage. Regularly check the coolant level and top it up if it's insufficient. If suspended particles, sediment, discoloration, or deterioration are observed in the coolant, replace it immediately and clean the system. Coolant replacement procedure: Before a complete coolant replacement, conduct a thorough inspection to check for leaks or cracks in all hoses, with special attention to the five-way hose. The five-way hose, named for its five connection points to different components, distributes coolant to various parts of the vehicle. If there's any coolant leakage in this section, replace the hose or resecure the connections as needed. Drain the old coolant and flush the channels with clean water. Add water to the coolant reservoir and continuously flush the engine cooling system. Then, idle the engine for 3 to 5 minutes to circulate the water. Initially, the water draining from the reservoir may appear slightly pinkish. Continue flushing until clean water flows out. Remember to disconnect the heater hose and drain the heater core completely. About an hour after draining, add new coolant through the radiator hose for quick filling. Then, pour another batch of coolant into the reservoir until it's nearly full. Run the engine for about 10 minutes. As some air is purged from the system, the coolant level will drop. Top up the coolant to the "MAXT" mark on the reservoir.
When my car was almost three years old, the coolant color had noticeably turned cloudy. The mechanic said this regular red coolant is best replaced every two years. One summer, while running the AC on the highway, the temperature gauge nearly hit the red line, which scared me into rushing to the auto repair shop. They used a small thermometer-like device to test it and shook their heads, saying the freeze protection was no longer effective. Later, I switched to a long-life formula, and now five years have passed, with every maintenance check showing good condition. Actually, coolant doesn't just prevent freezing; it also prevents rust and boiling. Friends in the south should also pay attention, as cooling system issues might leave you stranded with an overheated engine.
