I just purchased an 03 cooper s and am losing coolant internally,no external leaks.Milky oil as well.Found out that the head gasket was replaced 1000 miles ago,and the head was not milled.Is it possible to mill the head on these? I have heard of some machine shops having a fixture that heads can be bolted to it and super heated to make them flat again.Is this a common issue on mini coopers? The leak is very slow and the level will only drop overnight.If it were a crack would it leak faster than this? I just think that the head may be slightly warped and is seaping coolant in the oil.

 

Did they use the OEM thicker gasket ? If not, then that's probably the issue.

 

This:CYLINDER HEAD GASKET ASBESTOS-FREE - 0,95MM(+0,3)
Part no. 11127508544

Instead of this: CYLINDER HEAD GASKET ASBESTOS-FREE - 0,65MM
Part no. 11127508543

And if they used a "high performance" aftermarket gasket, I am not surprised of the outcome. Happens fairly often.......