How Often Should the Original Coolant Be Replaced?

[OPaislee]

Vehicle coolant generally needs to be replaced every 2 years or 40,000 kilometers, which is just a reference interval. For commercial vehicles with longer mileage, the replacement interval should be shorter. Since driving conditions vary for each vehicle, the actual replacement should be based on usage. Monitor the coolant's condition—if it is insufficient, replenish it promptly. If suspended particles, sediment, or signs of deterioration or discoloration are observed, replace the coolant immediately and flush the system. Coolant Replacement Procedure: Before a complete coolant replacement, conduct a thorough inspection to check for leaks or cracks in all hoses. Drain the old coolant, then flush the fluid channels with clean water. After draining for about an hour, pour the new coolant into the radiator's hose. Methods to Determine Coolant Deficiency: Observe the coolant warning light on the dashboard. If illuminated, it likely indicates low coolant, though it could also signal excessive engine temperature. Inspect the coolant reservoir. If the level is below the minimum mark (MIN), do not continue driving; add coolant promptly. Check the water level markings on the coolant overflow tank. The normal coolant level should be between the MAX and MIN marks. If it falls below the MIN mark, the coolant is insufficient.

[Ruth]

I prefer following the manufacturer's maintenance manual. Generally, the coolant replacement interval for new vehicles is every 2 to 3 years, or every 30,000 to 40,000 kilometers driven. This is because coolant doesn't just prevent freezing—it also protects the engine from corrosion and boiling degradation. Over time, the additives in the coolant break down, reducing its effectiveness and potentially clogging the radiator passages. I recommend checking the fluid level and color every two years. If the liquid appears cloudy or shows signs of rust, it should be replaced early—don't wait until winter when the engine suddenly overheats, which would be troublesome. Regular replacement saves money by avoiding major engine repairs. I always schedule appointments in advance with professional shops to ensure the correct OEM-spec fluid is used, preventing chemical reactions from mixing different brands.