Coolant Loss Due to Leak from Expansion Tank on BMW Z4

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.

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Average mileage: 76,094 (58,000–107,000)
4 model years affected: 2003, 2004, 2005, 2008
20 people reported this problem
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Viewing 1 - 12 of 12 problem details
Found a hairline crack in the coolant expansion tank that was causing a slow leak. I replaced the tank and the problem was resolved.
2003 BMW Z4 63,400 mi,
Complete cooling system replacement inc. hoses and belts.
2005 BMW Z4 59,658 mi,
expansion tank developed a leak
2003 BMW Z4 74,000 mi,
Bmw repair flow Winston Salem
2005 BMW Z4 105,000 mi,
coolant expansion tank has small leak
2008 BMW Z4 84,000 mi,
2" hairline crack on the front of the expansion tank resulting in spewing coolant everywhere on the floor
2003 BMW Z4 91,000 mi,
bought 1 week ago.after 4 days coolant light came on.tank bubbling and water leaking from it.taken to garage.engine runs nice.
2005 BMW Z4 62,250 mi,
Expansion tank started leaking, expansion tank, upper,lower hoses are being replaced. costs $700 at mechanic, $1500 at BMW service. I go with mechanic
2004 BMW Z4 67,500 mi,
Cost me 1000 and two weeks no zed
Cracked expansion tank
2004 BMW Z4 68,000 mi,
Coolant expansion tank pinhole leak
2004 BMW Z4 58,000 mi,
Top of the tank blew off.