Why is the BMW 5 Series always low on coolant?

[Jones]

BMW 5 Series frequently being low on coolant may be caused by a stuck float in the coolant level sensor, a leak in the cooling system, or normal consumption and deterioration of the coolant. Cooling system leak: Check the actual coolant level to see if it's low. If the coolant is insufficient, there might be a leak in the cooling system. Solution: Add coolant to the reservoir, fill the radiator to the upper limit, and then bleed the system. After driving for a while, check the level again. If the level is normal, you can drive with confidence. If the coolant is still low, it might indicate internal engine coolant burning, which may require an engine overhaul. Stuck sensor float: Another scenario is when the coolant level in the reservoir is at the upper limit, but the dashboard still prompts to add coolant. This is relatively common in BMW 525 models and is usually due to a stuck float in the coolant level sensor. Replacing the coolant reservoir will resolve the issue. Normal consumption and deterioration of coolant: Vehicle coolant will naturally deplete and deteriorate over time, so it's essential to regularly top up and replace the coolant. When adding coolant, ensure the engine is cold to prevent burns and ensure safety.