The M5 is making a strange noise and I am hoping to get some help with it. The noise sounds like a bad wheel bearing in the front left wheel but it is NOT! It is engine and RPM related. The noise is a groaning type wha wha wha noise and comes on around 2K RPM's. NO CEL, no loss of power. The only recent work was a fresh belt change by my mech and I fixed the oil filter canister with new mounts. It is def coming from the left side of the engine, maybe a bad pulley? Any ideas guys? Thanks.