What to Do When the Mercedes-Benz E260 Displays 'Add Coolant'?
2 Answers
Mercedes-Benz E260 displays 'Add Coolant' solution as follows: False Alarm: This is usually an issue with the liquid level sensor and its related wiring. To determine if it's a false alarm, you can only manually open the coolant cap and observe whether the actual liquid level is normal. Engine Cooling: Park the car on level ground and wait for the engine to cool down. Ignition: Put the car into ignition mode. Check Water Temperature: The cooling system is pressurized, so you can only open the radiator cap after the engine has completely cooled down. The coolant temperature gauge must display below 70 degrees Celsius, otherwise, you might get scalded by the high-temperature coolant that could spill out. Filler Cap Operation: Place a cloth over the antifreeze filler cap, turn the cap counterclockwise half a turn to release any remaining pressure. Observe Coolant: If the coolant is level with the indicator rod on the filler cap when cold or about 1.5 cm higher when hot, it indicates there is sufficient coolant in the radiator. Actual Coolant Consumption: Coolant is a mixture of various additives and distilled water. Water evaporates, so as the mileage increases, the coolant will indeed be consumed. After being prompted to 'Add Coolant,' fill it up and observe again. If the prompt reappears shortly after, it indicates that it's not normal consumption.
Seeing the coolant warning light on my Mercedes E260, I immediately pulled over to check the coolant reservoir and found the level was very low. This is quite common and could be due to normal consumption or a minor leak. I quickly topped it up with Mercedes-specific coolant, avoiding tap or regular water to prevent engine corrosion. When adding, don’t fill it completely—leave some space to account for thermal expansion. After fixing it, I drove to the repair shop where the technician found a slight leak in the radiator and replaced the seal, solving the issue. I recommend keeping a bottle of suitable coolant in your car for emergencies, as engine overheating can damage components—safety first.
