That's the normal engine to chassis ground cable. It's a common failure point due to corrosion. On my 08 535 it was n the same condition.

The other main ground is next to the battery. Double check that it is intact and attached properly.

The starter is grounded through the case. No ground direct to the starter.

__________________
Dave

'05 325xi
'10 E70 35d
'85 911 Carrera
'66 911 Work in progress
'91 Chevy C1500
'95 Jeep Cherokee
‘18 Jeep JLU