What Causes the BMW to Display an Engine Overheating Warning?
2 Answers
BMW displays an engine overheating warning due to the following reasons: 1. The electric fan is not functioning or lacks sufficient power; 2. Insufficient coolant in the cooling system; 3. Malfunction of the water pump thermostat. For optimal operation, a car engine requires a specific working temperature—both excessively high and low temperatures are detrimental to its normal functioning and performance. The cooling system's role is to maintain the engine within the most favorable temperature range, thereby enhancing engine power while reducing wear and fuel consumption. Both overheating and undercooling adversely affect engine performance. The engine coolant temperature must remain within a specified range, with the normal temperature indicated by the central position of the gauge at 90 degrees Celsius.
Last time I drove my friend's old X5, I encountered the same issue—the temperature gauge suddenly shot up to red during summer traffic jams. It turned out the radiator was clogged, especially with tiny insects covering the cooling fins, which drastically reduced its efficiency. This is particularly important to watch out for during the willow catkin season in northern regions. Another possibility is a coolant leak—I've personally seen cases where water seeped from the tank's seams or slow leaks caused by aging water pump shaft seals. If the electric fan isn't running, the engine is especially prone to overheating when idling at a red light. In such cases, it's best to turn the heater to maximum to help cool the engine. Lastly, don’t forget to check for a stuck thermostat—BMW's variable-flow water pump system is particularly delicate.
