This expansion has no leaks and is off my E46 325i Auto which has done 70000 miles. The bobber inside the tank became wedged into the side of the tank during a coolant change and snapped. I bought myself a new tank anyway but this has been on the car for a year in this state with no issues other than not being able to use the bobber to check coolant levels, I just use a torch and check myself. The tank has no leaks or cracks and comes with an official BMW screw on cap (Which are ridiculously over-priced on their own), a coolant temp sensor in working order and the Max/Min guide attached. I don't want to just throw this away so if anyone is in a pinch or just wants to use the other parts supplied, hope it can help, thanks, Dale.
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