2003 BMW Z4 Why does coolant leak under car when coolant at max level but not at min level?
Why does coolant leak under car when coolant at max level but not at min level?
What is your question?
I have paper towels under car to monitor the coolant leak. The majority of leak is in the middle of car, between the front tires. I've only driven 2K miles in 12 months but no overheating yet. The heater core is not leaking because no leaks inside or foggy windows. It's not the water pump because no whining sound and no steam coming out. The radiator hoses appear to be in good shape and no hissing sounds. It's not the intake manifold because car runs fine, good fuel economy & no engine misfires. The radiator cap is not leaking. Everything you read points to a leak in the expansion tank. However, coolant leaks are barely noticeable when the coolant level is low (at minimum level) but still has plenty of coolant in the expansion tank?
What makes this problem better or worse?
It seems worse when I run the heater. It seems less prevalent when running the A/C.
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