What is the replacement interval for antifreeze?
3 Answers
The replacement interval for antifreeze is 2 years or 40,000 kilometers. The replacement method is as follows: 1. Park the vehicle for a period of time, wait for the antifreeze to cool down, then locate and loosen the antifreeze drain valve at the bottom of the radiator. When no more antifreeze flows out of the drain, the old antifreeze has been mostly discharged; 2. Keep the car idling, while pouring clean water into the antifreeze reservoir to continuously flush out the residual antifreeze in the cooling system until the discharged water appears colorless; 3. After the clean water has been completely discharged, tighten the drain valve, turn off the engine, and add new antifreeze to the reservoir until the liquid level is between MIN and MAX; 4. Start the engine for inspection. While idling, air will be expelled from the cooling system, and the antifreeze level will drop accordingly; 5. Wait for a few minutes until the antifreeze level stabilizes, then top up the antifreeze to between MIN and MAX.
I've seen too many car owners neglecting coolant maintenance at auto repair shops. Conventional green coolant should be changed every two years or 40,000 km, while extended-life orange coolant can last five years or 250,000 km. Never judge by color alone - last time a car's radiator corroded due to mixing incompatible coolants. The most accurate method is using a refractometer before winter; the freezing point should be at least 10°C below your local minimum temperature. Modified cars or vehicles under heavy load require shorter intervals - I've seen southern drivers go five years without changes until their water pumps rusted through. Always have mechanics thoroughly flush the system during changes, as residual old coolant contaminates the new fluid.
As a long-distance driver, I'm accustomed to checking the antifreeze condition every 30,000 kilometers. Regular vehicles typically require replacement every two years, but my SUV's manual specifies a long-life type needing replacement every five years. Daily attention should be paid to the coolant reservoir level - if it falls below the MIN mark, top up with the same OEM product. Last winter, I noticed an oily film on the surface, which the technician identified as a sign of cylinder gasket leakage. In hot regions, pay special attention to the boiling point - my colleague in Xinjiang once had an engine boil-over due to degraded antifreeze. The OEM manual actually explains everything clearly: different brands have vastly different formulations, so never trust generic replacement solutions found online.
