[jimbob2010]

hi all,
I have a 56 plate 320si and it runs real rough on idle, dealer said a software upgrade will cure it but this has been done and failed miserably. Then they said the timing would have to be adjusted, this also has not worked.
Any suggestions?
I dont think the valve clearances have been checked, is it true this must be done every other oil change?
Any advice would be greatly appreciated.