It sounds like your rotors are warped, time to change them.
I use Mobil One 5W30 on mine.

__________________
/ / / Mike
BMW X5 Xdrive50i 2015 F15
BMW 325iC 1992 E30
BMW X5 4.4i - sold
BMW 335i X Drive 2010 - sold
BMW Z4 3.0is 2006 - sold
BMW 325is 1993 - sold
BMW 2002 1976 - sold

X5 Garage