What Causes the Coolant Refill Prompt in Mercedes-Benz?
2 Answers
Common causes of antifreeze leakage in Mercedes-Benz vehicles include: aging or damage to the cylinder head gasket, aging or damage to the return hose, damage and leakage in the auxiliary water tank, and leaks in the sealing rings on the coolant pipes, which may be accompanied by an increase in engine oil level. How far can you drive when prompted about low coolant: The reduction in coolant varies for each individual—some due to normal consumption, others due to leakage. Therefore, it's impossible to determine exactly how far you can drive. However, continuing to drive after the refill prompt will likely trigger a "coolant high-temperature warning," followed by an "engine high-temperature warning." If you suddenly receive a "refill coolant" prompt while driving and don’t have any spare coolant on hand, you’ll have to keep moving forward. In this case, pay close attention to high-temperature warnings. Once the "coolant high-temperature warning" appears, pull over and take a break, then drive a short distance and stop again until you reach a repair shop. Throughout this process, always monitor whether an "engine high-temperature warning" appears. If it occurs within a very short distance, it’s best to wait for roadside assistance.
I've been driving a Mercedes for years, and when the coolant refill prompt pops up, it's mostly due to insufficient coolant or a leakage issue. During long-distance driving, coolant naturally evaporates and decreases, just like how water in a kettle reduces over time due to steam. If the fluid level remains low for too long, the system will automatically remind you to avoid engine overheating and malfunctions. The most direct causes could be small cracks from aging pipes or leaks due to loose radiator connections; sometimes, it's the water pump's seal not being tight enough, as that thing vibrates a lot during operation. I recommend first opening the hood to check the coolant reservoir's fluid level—if it's below the marked line, you'll need to top it up. Remember to use the specified type of coolant; don't just add water. If the prompt persists after refilling, it might be a faulty level sensor, and you should visit a 4S shop for a computer diagnostic. Don't push your luck and keep driving, or you might end up stranded on the road.
