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.

RepairPal Verified
Average mileage: 76,255 (58,000–107,000)
4 model years affected: 2003, 2004, 2005, 2008
19 people reported this problem
11 people shared 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 Z463,400
Complete cooling system replacement inc. hoses and belts.
2005 BMW Z459,658
expansion tank developed a leak
2005 BMW Z4105,000
coolant expansion tank has small leak
2008 BMW Z484,000
2" hairline crack on the front of the expansion tank resulting in spewing coolant everywhere on the floor
2003 BMW Z491,000
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 Z462,250
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 Z467,500
Cost me 1000 and two weeks no zed
Cracked expansion tank
2004 BMW Z468,000
Coolant expansion tank pinhole leak
2004 BMW Z458,000
Top of the tank blew off.
Related Items:
Think it might be the expansion valve. How much to replace it?
was told that fuel tank flaps are broken and whole tank to be replaced. Also now fuel indicato...
My car only has about 80K miles on it and my air compressor is leaking oil. Can I just have my...
Valve cover gasket leaks are common after 60,000 miles. Symptoms will include oil drips under t...

Related Content