How to Solve the Constant Low Coolant Warning in BMW 525?
2 Answers
BMW 525 displays a low coolant warning due to reasons such as insufficient coolant, damage to the coolant reservoir, or deterioration of the vehicle's coolant. Insufficient Coolant: Check the actual coolant level to determine if it is low. If the coolant is insufficient, there may be a leak in the cooling system. For example, leaks in the pipes or radiator require immediate inspection at a repair facility to identify the exact leak point. If the leak is not visible to the naked eye, professional pressure testing is needed. Damaged Coolant Reservoir: The coolant level in the reservoir may be at the upper limit, but the dashboard still prompts to add coolant. This issue is relatively common in BMW 525 models and is often caused by a stuck float in the coolant level sensor. Replacing the coolant reservoir can resolve the problem. Deteriorated Coolant: Vehicle coolant naturally depletes and deteriorates over time, so it is essential to regularly top up and replace the coolant. When adding coolant, ensure the engine is cold to prevent burns and ensure safety.
My BMW used to frequently show low coolant warnings, and it took me several attempts to figure out the issue. The most common causes are leaks at hose connections or the radiator, so carefully check the engine bay for red coolant stains. Also, that plastic expansion tank is particularly prone to cracking, especially in older cars. Last time I replaced the tank, it cost me over 800 yuan. If the leak isn't obvious, remember to check the coolant level on the cold engine every few days. Adding OEM coolant as a temporary fix is fine, but you must locate and fix the leak ASAP, or you risk engine overheating and cylinder scoring—that would be disastrous.
