04 Mini Cooper S, manual 6 speed..I recently ran battery too low to start, so I took the battery out and charged battery overnight..next morning..I tried to start..no crank..only a progressive humming noise..starts at a low frequency then runs up to steady sound..stops when key off..towed to mechanic..they unloaded it..started right up..next day, drove 20 miles ,played golf, went to start..same sound..towed again to same mechanic..same thing..started right up..they changed starter motor..ok, for 10 test starts..failed on 11 th..they realized it was not the starter..put old starter in..now trying to reproduce fault..no fault codes..could it be that the ECM just needs some miles on it to reset itself after removing battery..mechanics are pulling their hair out figuirng this one out

 

Good list of DIYs here also.

https://www.northamericanmotoring.com/how-tos/

Gen 1 MINI: https://www.northamericanmotoring.co...001-2006-40469

Gen 2 MINI: https://www.northamericanmotoring.co...007-2013-40470

Gen 3 MINI: https://www.northamericanmotoring.co...-present-40471