Coolant Loss Due to Leak from Expansion Tank on BMW 330xi

Problem Description and Possible Solution

An engine coolant leak may develop from the expansion tank resulting in engine overheating. When a cooling system component fails the entire cooling system should be inspected. It is not uncommon to find additional component have failed or are leaking.

Overheating can cause severe engine damage. If the engine begins to overheat it is recommended to stop at the first available location and have your vehicle towed to a repair shop.

Problem Data
RepairPal Verified
Average mileage: 114,214 (78,000–162,000)
6 model years affected: 2001, 2002, 2003, 2004, more2005, 2006
16 people reported this problem
Viewing 1 - 4 of 4 comments
over heating and coolent leak from driver side up front. discovered it was the expansion tank. treplace tank and solve issues.
Tried to top off with distilled water when low coolant light came on. Kept having to to off. Started overheating. Next morning tried topping off. Drained right out of the expansion tank. Going to remove expansion tank for inspection.
Drove into my driveway and sudden stream of fluid from under the car and steam from under the hood. scared the daylights out of me- thanked my lucky stars that this occurred when I was home. Tow picked her up and had had her back within 1 day...