2004 m 45 sqeeching sound

[kingpin]

new belts in the front , the car makes loud squeching nose when it starts to roll , i had it at the dealer and they said it was the brakes but as soon as i drove out it started again , drop it off friday waiting until tuesday to pick up - any ideas >>>>>

[SteveTheTech]

Brakes. The Y34 uses auto tensioners to keep the belts tight, so belts are out. Since you say it happens once you start rolling, brakes are suspect. You mention the dealer told you it was the brakes but neglect to mention whether you had anything done to resolve the noise?

Sounds like you may have some acid damage on your rotors. What type of pads are you using?

[kingpin]

i

it its the brakes!~ how come it happens when i am stop at the lights also ?

[SteveTheTech]

Maybe one of your drive pulleys' bearings are failing. From the description you gave and the back story you provided brakes seem like the most likely causes.

[maxnix]

Barely perceptible bearing flaws when manually spinning the pulleys are magnified x100 under stress.

Did you check each one?