I have a similar symptom, but would describe it as a squeal under load, common when cold, less so when warmed up. Was thus far assuming bearings, & I needed to look for an oil leak?

__________________
Chris

~~~~~~~~~
'10 X5 35D - Performance mods & Kassel tune // '04 Mini R53 - lots of mods, rebuilt // '03 Mini R53 - sold
'05 X5 3.0i - Recently acquired for wife & daughter
'03 X5 3.0i - lots of upgrades, passed to son // '98 540i - other son's
'94 E36 318ic - son's wrecked // '96 E36 328ic - son's sold