Car is currently at BMW getting service done. They said the threads for the sump are gone and as a result cant put the plug in. They have quoted £1000 for new sump which seems crazy. I spoke to an independant guy who can do Helicoil. Only thing with this is the sump would have to come off before this is done as dont want any swarf etc getting in engine, is this a big job? or can it be done saftley leaving the sump on? Any help on this greatly appreciated.